eHam.net - Amateur Radio (Ham Radio) Community

Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net



[Articles Home]  [Add Article]  

Antenna Lessons from the Old Timers

Don Keith (N4KC) on May 24, 2007
View comments about this article!


Lessons From the Old Timers

By Don Keith N4KC (www.donkeith.com)

Down here in Alabama, we know that three things inevitably lead to fistfights:

  • Where your loyalty lies when it comes to Alabama or Auburn football

  • Which rib joint has the best barbecue

  • And which route offers the quickest trip to the beach

On the ham bands and in Internet forums, there are at least three equally incendiary topics:

  • Contesters “crowding the bands”

  • The FCC dropping the Morse code requirement for new licensees

  • And whether an antenna cut to resonance radiates better than one that is not

Don't think these are hot topics? Then you have not been listening or reading! I'll leave the first two alone for now so I can foolishly—and at risk of “flaming,” personal attacks, and questions about my heritage—take on the third topic. I do such a silly thing primarily for three reasons:

  • We are enjoying an influx of newly licensed and newly privileged HF operators who might be able to benefit from a rational discussion on the subject.

  • We now have TEN amateur radio HF bands, and extended Advanced/Extra SSB privileges that challenge the bandwidth of most antenna system installations, especially on 80/75.

  • And as a student of history, I maintain that we can learn valuable lessons from those who came before us. The old timers who pioneered radio were correct on lots of things…including getting the most from limited antenna systems.

Here's the contention of many otherwise knowledgeable hams: you are always better off using an antenna that is cut to resonance for a particular operating frequency. That claim, many say, should be engraved in stone. It's one of the great truisms.

“Resonance.” It sounds like such a nice word. “We're in resonance on that issue, my friend.” “That topic resonates with the people!” Dictionary.com defines the word thusly: “To reinforce oscillations because the natural frequency of the device is the same as the frequency of the source.” Who could possibly argue with such a wonderful purpose? Don't all we hams want to reinforce oscillations? I know I do!

To cut to the chase, when talking about antenna systems, we call them “resonant” when the capacitive reactance present in the system is equal to the inductive reactance, and the two cancel each other out, leaving the impedance at the load point at its design value—typically 50 ohms. In that magic alignment by the gods of RF, the antenna is able to radiate into space most of the radio frequency energy that is sent to it from the transmitter via a feed line. Everything seems predestined to work well together. A dipole antenna hanging high between two trees will—on its design frequency and if properly constructed—present something close to 50 ohms impedance. Our typical coaxial feed line has a characteristic impedance of 50 ohms. The output circuit of your YaeKenEleIcomTech radio craves a 50-ohm load.

There we are! Resonance! Maximum transfer of energy occurs! Music swells, flags unfurl, the sun breaks through the clouds, and all is right with the world! We have achieved resonance!

But then, relatively new ham radio operator, you simply cannot leave well enough alone. You go and do something dumb, like touch the tuning knob and change frequency up or down the band in search of new people with whom to chat, or you go off down the band looking to chase some rare morsel of DX. Or, in a truly desperate move to find someone to talk with or to seek better propagation, you flip the switch to change to another amateur band entirely. Suddenly, your fancy, new transceiver is faced with an impedance value that is considerably removed from the Holy Grail of 50 ohms. The value may climb into the hundreds or even thousands of ohms, or drop to almost nothing, becoming disgustingly capacitive or inductively reactive. Suddenly, standing waves are introduced into the system as the RF energy encounters the ugliness of non-resonance. Energy is rudely deflected back down the coaxial feed line, all the way to the output of the transmitter from whence it came only a fraction of a second before, but it does not like the 50 ohms it finds there either. Zoom! Off it bounces once more, back up the cable, waving at its friends who are on their way back down already. But there are fewer and fewer of the reflected radio frequency waves now because some of them are being burned up—zapped energy—due to the loss in the coax.

Thankfully, if the carnage is too much—the standing waves too large a portion of the originally emitted energy—the transmitter does the only humane thing it can do. It shuts down. Then it refuses to operate at that wavelength ever again. You, dear operator, have no other choice. You return to the vicinity of the spot on the dial for which you originally designed that antenna, ignoring the limitless other frequencies and bands where others seem to play at will with no concern for the impedance encountered by their shiny YaeKenEleIcomTech radios.

But how do they do it? Gosh, there are ten amateur HF bands, and some of them are remarkably broad. Your transmitter only seems to like certain spots on those bands—those that are odd multiples of the design frequency of your nice dipole antenna, but those are few and far between and are mostly dead all the time. Finally, you ask another ham when he wanders down to where you are stuck, in the middle of the band. He is on the air, operating all over the spectrum, even though his signal is not really all that strong when compared to some of the others. Still, he seems able to move and transmit even when he is farther away than a few kilohertz in either direction, so you swallow your pride and ask him how he does it. Somehow, you manage to pull his answer out of the static and noise.

An antenna tuner! Well, of course! All you need is that wonderful device that allows you to show your expensive radio a nice 50-ohm match and all is right with the world. You can dash and flip all over the RF spectrum, working everything you hear. You had no idea the answer was so simple! Soon the box arrives from the manufacturer and you hook the “tuner” up between the rig and the coax feed line. You follow the directions and soon, after some spitting and sparking somewhere inside the radio as you learn to adjust the capacitor and inductor inside the shiny, new box, it shows you a wonderful thing on its sexy front-panel meter—a near one-to-one SWR! The rig's happy again. You go off to the hinterlands of each band, trying the thing out. It still balks in some places, but for the most part, it seems to load fine.

It should. The manufacturer's catalog said it would match almost any load. You've heard guys talk about loading to a bedspring, a hank of wire tossed out the window, a screen door. And it cost two weeks' salary. It has to be good!

Soon you are able to transmit on frequencies previously unavailable to you, using your high-hung, well-designed dipole all over creation. Sometimes you actually get a response to people you call, though they often lose you before the QSO is completed. You even work DX, though the reports are typically bad, and you never seem to be able to get through in the pileups for the really rare ones. The mic bites you when it touches your lip while you are talking. The XYL complains about the answering machine starting up by itself when you are on “that #%&*@ radio!” The neighbor lady stares at you angrily when you meet at the mailbox.

Hey, the sunspots are really bashful nowadays. The ionosphere sleeps most of the time. You only have a hundred watts. The bands are rife with static this time of the year. All ham stations have some RFI and the fact that your mic stings your lip confirms for you that the rig is making RF somewhere inside its box. You'll do a better station ground someday, even though you thought you had a pretty good one already. At least you are on the air, exercising those new privileges, having a blast in the world's greatest hobby.

But there is still that nagging suspicion that other hams are hearing and getting out better than you are. It can't be, though. You have a one-to-one SWR. The meter says so. That's the best you can do. The rig is happy. You work DX sometimes. You get through on the local roundtable most of the time. And all with that one dipole, the only antenna you will be able to put up for a while.

Then, one day you have a nice conversation on a band far removed from your antenna's design frequency, talking with a distant station who has a really big signal. You assume he is running power but when you ask what kind of amp he has, and that you've been considering getting one so you, too, can get out better, he tells you something that is hard to believe. Even though he has an amplifier, he doesn't even have the filaments turned on at the moment. He rarely uses the thing. Doesn't need to. You grin. The guy's clearly lying. He's what you call “arm chair copy,” one of the loudest signals on the band.

You ask about the antenna. He tells you it is a dipole, no higher or longer than yours. How about the tuner, then? Same make and model as yours. Lucky guy! He obviously lives in an RF hotspot, over great soil, maybe surrounded by saltwater. Nope. City lot. Rocky clay soil. Nearest saltwater is 500 miles away.

Then he casually mentions his feed line. It's something he calls “ladder line.” 600-ohm ladder line, homebrew, using bits of plastic coat hanger cut to 6-inch lengths to keep parallel runs of 14-guage wire an equal distance apart as it runs from the antenna feed point to the house. It runs right into the shack, through a feed-through in a windowpane, directly to the balanced output of his “antenna matching device.” For some reason, he makes a point of not calling the box an “antenna tuner.”

0x01 graphic

But what difference does this “ladder line” stuff make? You have some really nice RG-8X that the dealer said was perfectly fine for HF. And it is so easy to work with. “Ladder line” sounds ugly and not a little bit dangerous. And without a layer of copper shield to protect its insides, doesn't he have to be really careful where he runs the stuff to keep from frying neighborhood kids and small furry critters?

Then your new friend says he wants to tell you a few things about the old days so you will understand his preference for that old, outdated method of feeding RF to an antenna. You roll your eyes, check the station clock, and almost make up an excuse so you can tell him you have to QRT. But it's still a few minutes until net time so you humor the guy and listen to what he is anxious to tell you.

“Back in the early days of radio, hams had to find the easiest and most efficient ways of doing things,” he says. “Often they had to make whatever they needed. There was no coax back then. It had not been invented. They came up with air-dielectric feed line and found it worked very, very well. Nice, low loss. Cheap. Easy to make themselves. So the standard in those days was 600-ohm ladder line, two parallel runs of wire separated by some kind of non-conductive material every foot or so.”

600 ohms? Your ears perk up. You're still learning about all this impedance stuff, but you know 600 ohms is a heck of a long way from the 50 ohm match your rig wants. The 50 ohms your pretty run of coax presents. And a far cry from the impedance typically encountered at the feed point of a simple dipole antenna. You ask him the “SWR” question. Surely it was a problem, even way back then, when dinosaurs roamed the earth.

“Back then, the output circuits of the tube-type rigs they used had a great deal of matching range built in,” he explains. “Most of the inductors and capacitors we now find in our outboard antenna matching devices were a part of the transmitters way back in the early days. But even so, those guys not only didn't know much about standing waves, they didn't really worry much about it. The loss in that ladder line was so low, even if there was a mismatch at the antenna feed point, and even if there were standing waves on the line, the RF was eventually mostly all radiated. It didn't get lost in the feed line, like it can in coax.”

For some reason, you feel compelled to defend the honor of good, old coax. If ladder line was so good, why did everyone go to coax in the first place, once somebody built that better mousetrap?

“It is easy to use and work with, not a problem to run into a shack next to all kinds of other cables and metal, and the stuff works well in many instances,” your new friend acknowledges. “For unbalanced antennas or VHF and UHF, it's preferable by far. Remember, though, that back in the day, there were no 60-, 30-, 17- or 12-meter bands yet. Most ops used a relatively narrow range of frequencies, and the typical antenna farm usually consisted of a dipole for 80/75, a dipole or vertical for 40, and a tri-bander for 20, 15 and 10. Nowadays, with so many potential operating frequencies, few of us can manage antennas that are specifically cut to work on each of those bands. Thanks to the old-timers, we knew there was a way. And the way was the open-air-dielectric ladder line or mostly-open-air window line.”

Net time has come and gone but you still don't get it, so you ask him to clarify his position. “Wait,” you say, ignoring the tingle when the microphone brushes your lip. “You are saying SWR doesn't matter? That can't be!”

“Well, sure it matters, if it's high enough. But by simply using a much lower loss feed line, you make it much less a factor. Look in the ARRL `Antenna Book' at the comparative loss between different types of coaxial cable and ladder or window line. There is loss in any real-world conductor, but it is so much less in the old-fashioned stuff that it makes those trips up and down the feed line for reflected power much easier, and most of it gets radiated eventually by your antenna, not burned up in your coaxial cable.”

But what about that 600-to-50-ohm mismatch back at the rig? 12 to 1? Serious stuff! Your radio ain't gonna like that one bit!

“Best thing for a balanced, ladder-line-fed antenna system is what is called a balanced antenna matching unit, which is, of course, designed for matching a balanced antenna system. It does a nice, effective job of matching the 50-ohm output of your rig to whatever impedance you encounter. And believe me, that impedance will vary all over the place when you try to use one big dipole on all ten bands. But it is not really a worry. The low-loss line takes care of most load mismatches you'll see. Those standing waves eventually go dancing off into space to hopefully be reflected back to earth somewhere near that big dx-pedition everybody's calling.”

You check to make sure but you have a balanced output on your tuner…er…antenna matching device. Can't you just use that to match the antenna?

“Sure,” he says. “That's what I'm doing now, though I'm going to build myself a balanced tuner when I get the time and find the parts I need. It's an easy project, even for a beginner. You and I have a 4-to-1 current-type balun…a balanced-to-unbalanced transformer…in the ATU…antenna tuning unit, if you want to call it that…and the circuit inside the device will present a nominal 50-ohm load to your transmitter. Our balun is heavy enough to work fine at the power levels we use, but I have another much heftier unit I use when I throw on the afterburner. Some ATUs use voltage-type baluns or they simply are not built tough enough to handle the kinds of mismatches you may encounter on a very wide range of frequencies you will be able to operate on. Those don't give very good results and could even fail. By the way, I don't call them `antenna tuners' for a reason. You are not `tuning' the `antenna.' The typical way most folks `tune' an antenna is make it longer or shorter. What you are really doing with that box in the shack is matching your transmitter to the antenna system. It is an antenna system!”

How can you tell if the internal balun isn't “tough enough?” you ask.

“Smoke and flames,” he says and laughs. “Just make sure the thing is rated for much higher power than what you intend to run. By the way, there are other ways to do this thing, you know. Want to hear about them?”

You ignore the XYL screaming about your “Donald Duck voice” messing up “American Idol” on TV and tell him to go ahead. There are some logistical problems with open wire line, he admits. It needs to be kept at least a few inches away from other metal, cables, and the ground. He tells you about how some hams run the ladder line to a balun outside the shack and use as short a run of high-quality, low loss coax as they need to get inside the house and to the tuner. They usually have a one-to-one balun for this purpose since it's typically best to pass whatever impedance you encounter at the feed point to the tuner. If your system sees a very low impedance, you don't want to step it down any more. Matching devices do better when they are attempting to match higher impedances rather than lower ones.

Some fellows put a balun right there at the feed point, then run coax to the shack. That's not necessarily a good idea since there will still be standing waves as you move around the bands and they will still be dissipated as heat in the cable.

There are some who put a remote matching device at the feed point, tuning for 50 ohms, and then running coax. That works pretty well, but you still have to have an ATU that can stand weather, be light enough that it doesn't drag down your aerial, and has current running to it to remotely so you can change the capacitive and inductive parameters from your operating position in order to find the best match.

Other hams tape two runs of good, low-loss 50-ohm coax together and solder each of the two sides of the ladder line to the center conductors of the coax cables. Then the grounds are tied together on the matching device end and hooked to the station ground. Finally, the two center conductors are attached to the balanced output of the matching device. The twin-run of coax should be kept as short as possible, of course, but the 100-ohm impedance presented is little or no problem.

You think for a moment. You have saved your best question for last. You ignore the buzzing sound from your nearby stereo speakers as you speak into the microphone.

“But regardless of the feed line, using an antenna on frequencies where it is nowhere near resonant is not as good as having an antenna cut to resonance for that frequency, right? This is just a compromise and we pay a heavy price for trying to use just one antenna from 1.8 to 30 mHz.”

So you've said it. A cut-to-resonant-length antenna is always better. There is only a slight pause on the other end of the circuit.

“You've been listening to some of the guys on 75 meters, right? Or reading those forums on the Internet. First thing, don't think of it as an `antenna.' Think of it as an `antenna system.' There are lots of things that make up your antenna system—the output circuit of your transmitter, the cable to the ATU, the ATU, the feed line to the antenna, the antenna itself, the earth beneath it, the trees in your yard, the chain link fence at the back of the lot, a mountain a mile away, the atmosphere above you. Obviously you don't have much control over some of that. But you can bring a good portion of it into a state that is what we call `resonance.' You have two goals in the process.

“First, because of the way most of our solid-state radios are designed to work these days, you must present a load at the output of the rig that is relatively close to 50 ohms. Some radios are more forgiving than others, but a serious mismatch will either damage the rig or cause it to cut back power or shut off completely. Most amplifiers—and especially the new solid state ones—are just as picky about the load they prefer. If the mismatch is so great that the rig won't work, it's darn hard to make contacts!

“Your second goal in life is to cause the antenna…the wire-in-the-sky part of the system…to radiate as much of the power that you send it as it can. Yes, one way to do that is to trim the antenna so that it is non-reactive at a particular frequency—the one you use all the time—and close to 50 ohms. Then you can feed it with coax. Even then, you may want a balun at the feed point to try to keep common mode currents off the shield of the coax and stray RF out of the shack and house. That RF energy does you no good there. It just makes XYLs and neighbors really irritable and gives you a painful tingle sometimes. But remember, the farther you venture from the design frequency of the antenna, the greater the mismatch, and eventually, with coax, the standing waves will be high enough to cause loss of precious power. Yes, the antenna will work okay at odd multiples of the lowest design frequency, but how many of those actually fall within an amateur band? And yes, you may be able to dial in the right combination of inductive and capacitive reactance to please your radio, but you won't be throwing much of your original power in the direction of the DX station's antenna system.”

He offers to email you a diagram of the antenna system he built when he first began to experiment with the old hams' way of doing things. He promises it is cheap and simple, and that the dipole part of the antenna system is decidedly non-resonant—by itself—at an almost infinite number of frequencies. It is not even the best setup possible, he notes, but it is far better than what you are currently using. It is cut to be a total of a half-wavelength long (each leg is a quarter-wavelength and should be exactly the same length so it will be truly balanced) for the lowest frequency that is anticipated to be used…or that will fit in a yard. He maintained that it would work fine on most bands from there through ten meters when used with ladder line or window line, 300 to 600 ohm impedance, and a good quality one-to-one balun.

When the diagram arrives in your in-box, it looks like this:

0x01 graphic

After saying your 73, you sit back and think about what the nice Elmer has said. It does make sense. So much so that you invest in an antenna book and do some research on the web. Though you still see some of the “resonant antenna rules” posts and hear on the air lots of people preaching the gospel of the resonant antenna, you also see lots of information that backs up what the fellow said.

You Google W2DU and read excerpts from his book on the subject. You visit W4RNL's site and find a wealth of information. You purchase a good-quality one-to-one current-type balun, a spool of inexpensive window line, and a good, strain-relief center insulator designed for the open-air-dielectric feed line. Then, when you get the antenna built and up in the air, you marvel at what you have been missing all this time.

And you vow that from now on, you will begin listening to what the old folks say. Sometimes, while they were dodging dinosaurs and discovering fire, they actually figured out how to make simple antennas work much better!

Member Comments:
This article has expired. No more comments may be added.
 
Antenna Lessons from the Old Timers  
by SSB on May 24, 2007 Mail this to a friend!
This article does not go to the problem a large number of hams have which is no space for a full size antenna. Resonant antennnas are not always better if you can't fit one in the space available. This article does not give numbers backing up anything. If non resonant antennas are inferior then give me the numbers proving it is and by how much. This article suffers from the same vague info most of these articles have.

I have been using short antennas for a long time and they work within a db of full size versions. Why? Because I use loading coils with heavy ribbon coils. I use very efficient center baluns that are 25:1 to boost the center Z to 50+ ohms. I use home brew antenna tuners that make Palstars look like MFJ.

For all those who want to write antenna articles, give numbers and the source or derive the numbers or their measured value using decent and accurate test equipment. Otherwise, I am not listening.


Alex.....
 
RE: Antenna Lessons from the Old Timers  
by ONAIR on May 24, 2007 Mail this to a friend!
Any self respecting ham that knows anything about antenna theory realizes that a decent amount of real estate is necessary to put up the best antennas for the ham bands! Therefore, it is every hams duty to get out of their small crummy apartments or condos and get themselves a nice bit of acreage in the suburbs or the country. An antenna is 80% of any station, so the only way to do it right is to get away from small restrictive environments and move to a place where one can realize their true antenna building potential!
 
Antenna Lessons from the Old Timers  
by KF4HR on May 24, 2007 Mail this to a friend!
Interesting article. Another alternative might be to use a SteppIR antenna (variability resonate), and not worry so much about the minimal losses in a reasonable length of coax, because:

a) with good quality coax, (at HF frequencies) losses are typically minimal and,
b) any power that is lost in the coax will make little difference on the S-meter of the receiving station.

Then the more important questions might become, if I ground my station properly can I eliminate RF on the mic from biting my lip, and do I order my ribs wet or dry? :^))

KF4HR
 
Antenna Lessons from the Old Timers  
by W1YW on May 24, 2007 Mail this to a friend!
Don't use ladder line. Ever.

If you operate in a way that REQUIRES ladder line, then consider giving up ham radio and playing character roles at Medeival festivals.

I found these so-called 'lessons' of little use to anyone I am afraid. They are either obvious, wrong, or outdated.

But hey--lotsa people who aren't hams may read this, and if we steer the 'wrong ones' up a squirrel hole then we've done a 'blessing'.

!
 
Antenna Lessons from the Old Timers  
by NT4XT on May 24, 2007 Mail this to a friend!
Nice. Very nice article. FB OM. TNX ES VY 73.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 24, 2007 Mail this to a friend!
"If you operate in a way that REQUIRES ladder line, then consider giving up ham radio and playing character roles at Medeival festivals. "

Why? Did you come up with a proof that self-similar antenna structures always have higher gain when resistance at resonance is 50 ohms instead of, say, 450 ohms?

Just kidding... but I wonder what your particular objection to this particular feedline is?

Dan
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 24, 2007 Mail this to a friend!
Here we go again. ALL antennas are a trade off, a compromise at best, even one that is cut to frequency is compromised because it is only good on that frequency. The antenna described in this article, suffers from standing waves that are reflected back into the shack, RF in the shack, and severe antenna pattern distortion, especially on the higher frequencies. It also have to be built out of very hi-rated componets, because of the reflected energy creating lots of heat. There is NO perfect all band antenna that works equally well everywhere! Not to mention that this antenna design would be 270'+ long and won't fit on 95% of the lots that hams have. Use of the the "tuner" in the shack will tune out the reactance and/or capacitance presented at the end of the feed line, but it will do "NOTHING" with the reflected energy on the antenna itself. This energy will still go up in heat, and heat can't be heard!!!

Think of your antenna system as a speaker system on a stereo. Sure you can put all frequencies on a single speaker, but it certainly works and sounds better using a multi-spearker system with drivers designed to operate in a given frequency range. AF and RF share many of the same principles.

Over my 40+ years in the hobby I have learned there are 3 things that really work! Band conditions, Band conditions, Band conditions! If the bands are dead, there is no antenna in the world or amp that will work, and when it is in good shape, 5 watts of radiated energy will talk around the world.

Do what you have to do to get out and make your radio happy, but there will always be compromises.

73 de W4LGH - ALan
http://www.w4lgh.com
 
Antenna Lessons from the Old Timers  
by NA4IT on May 24, 2007 Mail this to a friend!
Nothing better than a resonant antenna...

fan dipole...

NA4IT
 
RE: Antenna Lessons from the Old Timers  
by AA4PB on May 24, 2007 Mail this to a friend!
I find the article neither wrong nor outdated. It is good, timely information. As it implies, the antenna "element" does NOT have to be resonant to radiate maximum power. The antenna "system" (element plus feed line) is tuned to resonance by the tuner. Its a good way to use a single wire antenna on all HF bands provided you can deal with the antenna size and the ladder line feeder.
 
RE: Antenna Lessons from the Old Timers  
by N4CQR on May 24, 2007 Mail this to a friend!
Good article. And for those who fear ladder line and twin lead, you can HTDR. Silly boys...

J C S
 
RE: Antenna Lessons from the Old Timers  
by K0BG on May 24, 2007 Mail this to a friend!
Sort of brings back memories. One of my early Elmers used a similar home brewed ladder line. In his case, it was made from 1/2 inch ridged copper water pipe. It was some 100 feet long, most of which ran up the side of a telephone pole to his extended zepp. The spreaders were made from soft pine, and paraffin soaked. It took him about 6 months to build.

The question remains, why don't amateur do this sort of thing today? Well, its because everyone seemingly is into instant gratification nowadays. So, it's why build what you can buy. We are (and have) diminished.

Alan, KØBG
www.k0bg.com
 
RE: Antenna Lessons from the Old Timers  
by LNXAUTHOR on May 24, 2007 Mail this to a friend!
- what was Marconi said?

"RF is funny stuff."

:-)

- tks for the article!

p.s. nothing beats a cheap $5 wire dipole at good height...
 
Antenna Lessons from the Old Timers  
by K1TN on May 24, 2007 Mail this to a friend!
Brilliant story. Top notch. Bravo.

Jim Cain, K1TN/2
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 24, 2007 Mail this to a friend!
NA4IT, you might offer to come out to new hams' houses and spend the time designing and executing a fan dipole that actually has an impedance around 50 ohms resistive on all 9 HF bands?

It's hard. You've got all these wires up there, each one is tightly coupled to the rest, and you're trying to use 468/f to calculate the proper lengths of the legs. You'll tear your hair out even if you have the space for a 160m-10m fan.

Once you get the monster up there, it's ugly... this big spiderweb of wires where you might consider just having one elegant wire.

Antenna element resonance is a religion among some of you guys. I'll agree that for two, or maybe three bands, a fan dipole fed with coax is a practical and straightforward solution. A 9-bander is going to be too sensitive to pruning and tuning... if we had 9 spatial dimensions so that every element could be orthogonal to every other element, it would be a different story.

There is a culture of obsession with 50-ohm resonant antennas... otherwise decent antenna designs get discarded just because they might need a little coil of copper wire and a decent capacitor to keep a transmitter happy. I personally prefer to keep coax feed and stick matching networks at the antenna... but that's simply personal preference for convenience in my installation.

There are plenty of good reasons to use antennas that aren't a ladder-line fed doublet (including, apparently, avoiding an appearance of goofy anachronism), but I prefer to select my antennas on the basis of *antenna performance* rather than feedpoint impedance.

A test: would you rather have a resonant dipole antenna or a 10dBi gain beam with a feed impedance of 250-j400 ohms?

Dan
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 24, 2007 Mail this to a friend!
"p.s. nothing beats a cheap $5 wire dipole at good height..."

What about a $20 4 element wire yagi at the same height ;-)
 
Antenna Lessons from the Old Timers  
by NB9D on May 24, 2007 Mail this to a friend!
I have an old book entitled something like "Dipole and Longwire Antennas" that was published by 73 Magazine many years ago (in the 1970's I think) that is probably one of the best overall sources for simple antenna design you will find. I don't know where that book is available because I am sure it is out of print, but I find it a very good source for really down-to-earth data for wire antennas. If you find one, get it; there is more good information packed in those small pages than probably any other book or web site. Unfortunately, most of the antennas in the book are full-sized requiring lots of real estate, and I agree with the other posters that this is increasingly a problem today with smaller lots and more restrictions. The overall objective in selecting an antenna is one that works within the available space, and having fun with it, recognizing that any simple antenna is a compromise on the ideal system.
 
RE: Antenna Lessons from the Old Timers  
by KG6AMW on May 24, 2007 Mail this to a friend!
Quote, "The question remains, why don't amateur do this sort of thing today? Well, its because everyone seemingly is into instant gratification nowadays. So, it's why build what you can buy. We are (and have) diminished."

Or maybe people are just too busy Alan.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 24, 2007 Mail this to a friend!
I can't see any better antenna system for instant gratification than a doublet fed with ladder line into a *good* tuner.

New hams are going to use their tuner on whatever they've got. I did it, for better or worse (and it didn't take me all that long to figure out which was which).

Dan
 
RE: Antenna Lessons from the Old Timers  
by K3AN on May 24, 2007 Mail this to a friend!
So if an antenna is resonant there's no reflected power on the feedline???

A resonant, yes resonant, folded dipole has an impedance of about 300 Ohms. Feed it with 50 Ohm coax and you've got those nasty reflections and standing waves. How could that be?

It's unfortunate that the author has introduced even more confusion to newcomers about antenna resonance vs a matched antenna system. An antenna doesn't have to be resonant to radiate efficiently.
 
RE: Antenna Lessons from the Old Timers  
by W9AC on May 24, 2007 Mail this to a friend!
"The antenna described in this article, suffers from standing waves that are reflected back into the shack, RF in the shack, and severe antenna pattern distortion, especially on the higher frequencies. It also have to be built out of very hi-rated componets, because of the reflected energy creating lots of heat."

One problem I see is either a mis-application of terminology or a lack of understanding of the subject matter altogether. What exactly is "reflected energy" and why does a balanced open line necessarily exhibit radiated pattern distortion? When we mention "reflected energy" are we really referring to the reflected wave?

The entire notion of "reflected power" is probably the most mis-applied term I've seen when discussing transmission lines and antennas. Power is not reflected to and from a load on a transmission line. It is the travelling wave, composed of a forward wave and a reflected wave, that propogates to and from the load from the source generator. It's the magnitude of a wave that ultimately disipates as power in a resistance.

Notwithstanding power disipated as a matter of line loss, the transmission line is nothing more than a transforming medium between the transmitter and the load. Power does not flow between the source and the load on a lossless transmission line. Think in terms of a forward wave and a reflected wave -- not "reflected energy," nor "reflected power."

The author of the article raises several good points, but one that should also be addressed is why a dipole fed with a near lossless 50-ohm line still cannot radiate as well on all HF bands as one fed with 600-ohm line when being used for multiband purposes. One must not only look at line loss, but the additional loss created by the line-to-load Z mismatch. When you look at the line-to-load mismatch charts, all of a sudden the entire picture of why a higher Z (e.g., 600-ohm) line works well into a load of vastly changing impedance as a function of frequency.

About a year ago, this topic was addressed in an issue of QST and was used in an excellent Smith Chart tutorial.

Paul, W9AC

 
Antenna Lessons from the Old Timers  
by AE6CP on May 24, 2007 Mail this to a friend!
Don,

Awesome.... ignore the naysayers. Honestly most hams, regardless of license class still do not REALLY understand SWR.. I didn't until about a year ago and I've had an extra ticket for about five years.
I think this is one of the most valuable bits of info for new hams and written in a way that won't loose the interest of a 15 year old brand new general ticket holder new to the HF bands.
I went through the exact same scenerio when I built my first HF antenna. I had a 40 meter dipole fed with coax and an automatic antenna tuner..... Worked great on 40 meters... worked like crap on every other band even though SWR was 1.5:1.
Here I am years later, I've been living in an apartment for two years with shortened, bent attic dipoles and Isotrons but... I'm moving to a new QTH next month with a huge yard and I've been cursing my antennas and saving my money for the day that I get out of apartment living. Now I have plenty of money and space to put up whatever I want... a 50ft tower with a four element Steppir was my first instinct... Not that the Steppir would not be a great antenna on the top five bands...
No, my first antenna will be a full size 80 meter loop made of 14 ga copper-clad steel up as high as I can get it, fed with homemade ladder line to a $700 Palstar BALANCED tuner the BT1500A.
Think I'm spending $700 on an antenna tuner because I'm a snob... Nope, read the ARRL comparisons at the following link:

http://www.arrl.org/members-only/prodrev/pdf/pr0409.pdf

The lesser antenna tuners exibit as much as 50% power loss and operating bandwidths as low as 0.1% of the operating frequency once tuned. The Palstar had loss of less than 10% (which is less than half a dB) on every band and bandwiths of greater than 100% of operating frequency once tuned.


Thanks again for the great article...
73,
-Larry
 
RE: Antenna Lessons from the Old Timers  
by N9XY on May 24, 2007 Mail this to a friend!
Great article... nice story to step the reader through the logic.

Sure, this solution is not workable for the apartment dweller, or those on a very small, or restricted lot. But for a lot of us, an antenna coupler and ladder line and lot's of wire is the way to go.

Sure it would be nice to be able to afford the STEPir solution.....

At this link is an interesting solution http://www.tuneatenna.com/
automtically tuned wire dipole.

73
Michael
N9XY
 
Antenna Lessons from the Old Timers  
by K2TV on May 24, 2007 Mail this to a friend!
Excellent Article! I've been using a 120 foot flat-top fed with 450 ohm ladder line for many years and it works fine. The antenna is fed with the ladder line going directly into the balanced output of antenna tuner. It will tune and radiate on all bands with no problem and will handle my amplifier during the few times I use it, although 99% of time the filaments are off. If you run anything more than 100 watts or so, buy or make the ladder line with the larger conductors. I even tie the two conductors of the ladder line together and feed it as a tee antenna for 160 meters which of course requires a good earth ground or radial system ground and RF is in the shack, so run low power on 160. It's a compromise on 160, but allows me to operate from a 70 by 100 foot lot. Remember that the antenna pattern will depend on the frequency and the height above ground as well as the position in relation to other metal objects in the vicinity.
I've worked individual DXCC on 80, 40, 30, 17 & 12 meters with little effort. On 10, 15 and 20 meters I use a HyGain TH3MK3 tri-bander and of course out performs the wire antenna on those bands.
If you want "numbers" for the antenna check the ARRL Antenna Handbook.

Bob Myers, K2TV
http://www.qsl.net/k2tv

ps. I guess I'm an "old timer" since I've been hamming for 47 years, but still young enough to learn something new.
 
RE: Antenna Lessons from the Old Timers  
by KA4KOE on May 24, 2007 Mail this to a friend!
...and friends ask why some of us don't do articles anymore; it can't be the nihilistic bomb-throwers who fail to be pleased by anything except their own negativism.

To the Author: Thanks for a cogent, well-written article. I use twin lead. Great stuff.

KA4KOE
 
RE: Antenna Lessons from the Old Timers  
by K0IZ on May 24, 2007 Mail this to a friend!
Don, very nice article. THanks for taking the time to prepare it. Reading some of the above responses, some people will never learn.

One error I see many hams making is believing that the reflected power (if not 1:1 SWR) is "lost" or "heating up" something in the transmitter. Suppose reflected power is 30% of actual power. When the 30% reflected power gets back to the coupler (tuner, Pi Network, etc), it is bounced back towards the antenna. When at the antenna, 30% of this 30% is re-reflected back towards the coupler (tuner, Pi Net, Etc). This process continues until the reflected power is minimal.

If the transmission line is lossy, the 30% reflected power is reduced twice (to coupler, back to antenna). Then the 30% of 30% is reduced twice, etc, etc.

But with a losses transmission line (open wire comes close), the reflected power will ALL eventually be radiated by the antenna. So a non-resonant antenna is 100% efficient (ie all power will be radiated) if the transmission line is 100% loss free. I'm also assuming for this example that the coupler has no losses.

Don, your antenna suggestion has withstood the test of time. Good job.

John.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 24, 2007 Mail this to a friend!
"Sure, this solution is not workable for the apartment dweller"

Actually, it was the BEST solution I could come up with.

I wound a bunch of magnet wire onto a drinking glass:

http://n3ox.net/projects/antennas/legowinder1.jpg

Shot out two random legs, each about 50 feet into two trees. One went pretty much straight out and up... the other had a bend in it at the tree and dropped down about 20 feet. Put a tuner about six feet from the feedpoint:

http://www.n3ox.net/projects/servo

It wasn't worth bothering with on 160m, but on 80m-10m it was a good antenna... nearly invisible. No one really seemed to notice. It kept me on the air, pulling down DX even though I was apartment-bound.

73,
Dan
 
RE: Antenna Lessons from the Old Timers  
by K0IZ on May 24, 2007 Mail this to a friend!
By the way, your antenna article is NO GOOD. I can't install it on my car .....

 
Antenna Lessons from the Old Timers  
by KE5ICG on May 24, 2007 Mail this to a friend!
Don, thanks for the article. I found it very interesting reading, and timely as well since I'm preparing to upgrade to General. I can see myself doing something like this pretty easily and for far less $$$ than putting up some big multiband vertical (not that there is anything wrong with that). My whole thing with ham radio is just to have some fun and maybe learn something interesting. Thanks for helping out with that . . .

73 to all -- Ray KE5ICG

 
RE: Antenna Lessons from the Old Timers  
by WA7NCL on May 24, 2007 Mail this to a friend!
This article certainly brought out the trolls early didn't it.

There were a lot of words in the article to come up with something that is found in a lot of getting started literature.

I'd say the biggest thing with antennas is to experiment, experiment. Cut up some wire, string it up and try it. If it doesn't seem to work well enough, ball it up and try some more wire. Its cheap fun.
 
Antenna Lessons from the Old Timers  
by K3SUI on May 24, 2007 Mail this to a friend!
Excellent article. Anyone who says that a non-resonant antenna fed with open wire line does not do an excellent job has NEVER tried it. Open wire line is a litte fussy getting it into the shack, but it is a very efficient carrier of RF when you run it in the TEM(balanced) mode. Please refer to W8JI's web site for very detailed information on this subject.
 
Antenna Lessons from the Old Timers  
by WW5AA on May 24, 2007 Mail this to a friend!
More antenna theory.....One hardly ever hears about using good receiving antennas.....Yes 80% of a good station is the antenna SYSTEM. For limited space, the receiving antenna is 80% of the system. To many run alligator stations at 1500 watts but are deaf because of that 1:1 wiz-bang folded dipole, shorty G5RV, or OCF dipole, and on and on. LISTEN....almost any wire antenna, resonant or not will transmit but will NOT Hear as well as a properly designed RX antenna. I am not talking about a 500' beverage either.

73, de Lindy
 
Antenna Lessons from the Old Timers  
by WA9UAA on May 24, 2007 Mail this to a friend!
Hi Don,
Another thank you for a nice antenna article. I have been running such an antenna system for years. I may try some heavy duty feeders just for the extra performance too. Some of these people need to take a good look at Maxwell's article on tuned antenna systems! Good ole KNS was saying the same things in the mid 80's.
73,
Rob WA9UAA
 
RE: Antenna Lessons from the Old Timers  
by N5KBP on May 24, 2007 Mail this to a friend!
I've run a 200 ft zep center fed with 450 ohm ladder line for years. Using an old Dentron super tuner it works great from 160 to 10. Heck I've even loaded it up on 6 meters a time or two. On the higher bands the clover leaf gain lobes give me great signal footprints into Europe, S Africa and the S Pacific. For a cheep, multiband HF antenna you can't go wrong with one of these.

Marty
N5KBP
 
RE: Antenna Lessons from the Old Timers  
by N0ZLD on May 24, 2007 Mail this to a friend!
Great article, thanks for writing it up and spending time on it.

There are so many negative people on this site it's sickening at times. If you don't have anything CONSTRUCTIVE to add, please, shut the hell up.
 
Antenna Lessons from the Old Timers  
by W3KM on May 24, 2007 Mail this to a friend!
Don,

Your article IS a very good one, regardless of some of the comments to the contrary.

Back in the 60`s es 70`s, I used open ladder feedline on HF and good foam 300-ohm twin lead on 220 and 432-MHz - both for the same reason - lower loss than coax and good on-the-air performance.

These days I have become less active and chose the easy way out on HF by using a long dipole with auto-tuner and hardline on VHF/UHF.

As was mentioned, numbers and performance data can be found in the ARRL, W8JK and W2DU and other publications.
 
RE: Antenna Lessons from the Old Timers  
by WB2WIK on May 24, 2007 Mail this to a friend!
I liked the pretty picture of the inverted vee installed over the crank-up tower, with the little puffy clouds in a blue sky background.

We need more excellent photography like this!

Now, what was the subject, again?
 
RE: Antenna Lessons from the Old Timers  
by W5ESE on May 24, 2007 Mail this to a friend!
Thanks for the good article. Very appropriate and
timely with Field Day approaching.

A balanced-line fed doublet offers good performance
and versatility for the cost and effort required to
put one up. Just what's required for smaller Field
Day groups.

73
Scott
W5ESE
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on May 24, 2007 Mail this to a friend!

Nice prose, but the article could have been shortened considerably to communicate 2 key points:

1) In the common context, "resonance" is not required for an antenna system to be an efficient radiator - which is the goal. Resonance implies a pure resistance AT THE DESIRED FEEDPOINT. Proper COUPLING of the transmission line to the load is key.

Problem is, for many antennas hams use, the feed point is reactive and requires some means of "coupling" to the transmission line. A couple of examples include:

> Yagi antennas; most require some sort of feedpoint matching device. i.e. Gamma, T and Hairpin (Beta) match.

> Center fed Zepp; Cut for a half wavelength on 80 meters, elevated ~ 1/2 wave over ground and fed with 600 ohm line, it presents a 70 ohm balanced load to the 600 ohm feed line, or an 8.6:1 SWR. That's not a problem so long as you use a suitable tuner and the open wire line is of good design, as the losses on the line are negligible at this frequency. But add a junk 4:1 balun in line with that "trusty" autotuner and all bets are off.

Using the Zepp on 40 presents an entirely different load for the line - approx. 5000 - j2000 ohms - hardly resonant in terms of being a match to the feedline impedance. But once again, since the 600 ohm line losses are very low on this band, the antenna tuner comes to the rescue and couples the 50 ohm transmitter to the complex line/load impedance.

2) Ladder line (and a G5RV) isn't a requirement for a good multiband antenna.

A Center Fed Zepp will get the job done as stated above and by the author. But so will a Trap dipole or vertical. Verticals can also be shortened without traps using various loading and coupling schemes and designed for multiband operation - etc,, etc....


...WA1RNE
 
Antenna Lessons from the Old Timers  
by N4VNZ on May 24, 2007 Mail this to a friend!
You need to give credit to www.w7fg.net for the nice photo of the tower and feedline.

I thought I had seen that pix somewhere before.

Yeah, I know it's not copyrighted, but you implied by your article that it was your photo.

73, Boog
 
Antenna Lessons from the Old Timers  
by N4VNZ on May 24, 2007 Mail this to a friend!
BTW, just throw up the longest piece of wire you have room for, cut it at a place where it will be easiest to run a feedline to your shack, feed it with ladder or window line, and use a quality tuner before the radio. Been using this philosophy for years with QRO and QRP and everything in between with no RF problems in the shack, etc. The only time I have ever had RF problems in the shack is when I was running coax feed.

If you DO use this idea, it is best to have at least a 1/4 wavelength at the lowest frequency on the shorter leg for easier loading.
 
RE: Antenna Lessons from the Old Timers  
by KD6NEM on May 24, 2007 Mail this to a friend!
Great article, very relevant to say the least. I had to snicker at some of the troll pundit comments, fortunately they were greatly outnumbered by those who appreciate this article and still have enough of an open mind to consider some truly effective options. To those who would ignore this article "unless it shows the numbers": get off your lazy duffs & check out the links to the w4rnl website & others. See if you even understand the all the many numbers there! There remains so much more to ham radio than just operating an appliance!

Thanks for an excellent article, Don!

Stu KD6NRM
 
Antenna Lessons from the Old Timers  
by K8VPL on May 24, 2007 Mail this to a friend!
Here are a few comments from an old radio broadcaster......concerning my experiences with vertical antennas, but the idea is applicable to all.

When using coax, always do what you have to, to match the coax. I.E. 50 ohm coax, driven by a 50 ohm source and looking into a 50 ohm load. That minimizes loss in the cable. Then match the coax to the antenna at the feed point of the antenna. The actual length of the radiating element(s) can vary a LOT.

I have seen, used, tuned up, and/or worked with all kinds of broadcast verticals, 1/4 wave (90 degree) and others. All were matched with a proper Antenna Tuning Unit at the base. Some towers were over 5/8 wave in length for the frequency in use. Several systems used all "non-resonant" towers in a directional system. All had substantial grounds under them, and all radiated very well. All used low loss tuning components to minimize resistive losses.

Feeding 50kw into a "short" vertical (170 feet on 1100 kHz) resulted in about 48 amps of base current. That was not a resonant quarter wave antenna....its "to short". Do your calculation for the actual driving point impedance. But, using properly sized components for the ATU, that tower radiated one whale of a signal.

So, it doesn't matter if an antenna is self resonant or not, what matters is the method used to transfer the power from the transmitter's PA, through the transmission line, to the ATU, and into the radiating element(s).

Of course, the amount of actual "radiator" you have in the air contributes to how much signal goes where, but resonance isn't the only thing.

How YOU do it is up to you. But aiming for lowest loss components, and matching EVERYTHING properly, usually results in best antenna performance for whatever size it is.

73.

Ted K8VPL
 
RE: Antenna Lessons from the Old Timers  
by KC8VWM on May 24, 2007 Mail this to a friend!
Well written and interesting read.

Sometimes in order to figure out our antennas in the future, we only need to take a few lessons from those in the past.

73 de Charles - KC8VWM
 
Antenna Lessons from the Old Timers  
by W1YW on May 24, 2007 Mail this to a friend!
Sound advice from K8VPL.

Expanding on my earlier comment--I don't know why hams think coax, at HF/MF, is particularly lossy. If you buy yours from a FLEA and its been buried 10 years and dug up, it will be lossy. But every piece of 100 feet of RG8U I've looked at with a VNA from 2-30 Megs has minimal insertion loss. All were better than spec. Of course I don't let crap coax into the lab, and if it sneaks in, it gets chucked. Who knows what water did on it's buried sleep?

Basically, IMO, if you can't afford to buy coax then don't be in ham radio.

Maybe you were one of the guys I caught fishing the dumpster outside the firm for the crap coax I chucked out??

If you want to MAKE a feedline, then go waste your time with ladder line. It says your time ain't worth much. And you don't know much about dielectrics; spacing; weight loading; transformer matching; and effects proximity to metal (such as towers).

The photo--and we still don't know who's photo it is-- is exactly the WRONG way to use ladder line, and is an outstanding example of why you shouldn't.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N4KC on May 24, 2007 Mail this to a friend!
Thanks for the feedback, guys. Three quick points:

--I wrote this, as mentioned, for relatively new hams, not for those of you who know it all already, but thanks for the input nonetheless.

--I did credit www.w7fg.com (who sells excellent open-wire feedline and complete antennas at a price at which he could not be making much of a profit) for the photo in the original draft of the article but the text somehow got lost in the upload of the manuscript.

--And, as an old broadcaster myself, I take no issue with K8VPL's comments. Only difference is that most broadcast stations sit there and crank away on a single frequency, day after day, year after year. I, as they say, "QSY" widely and on a regular basis.

73,

Don N4KC
www.n4kc.com
 
RE: Antenna Lessons from the Old Timers  
by KC8VWM on May 24, 2007 Mail this to a friend!
I also agree with K8VPL's theory behind good antenna design.

Focusing on the overall efficiency of the RF components used is a much better approach than focusing on building a 1:1 resonate dummy load.

Throwing any given 1/4 wave resonate antenna into the air just because it's "resonate" is no match for a well designed non resonate antenna where all the right components are selected for it's design, losses are taken into consideration, height above ground becomes a contributing factor and when the feedline chosen serves to maximize efficiency.

In that case, the non resonate antenna actually becomes the better antenna system.

Of course if we choose to install a resonate antenna AND we take into account all of the other vartiables to maximize it's efficiency, then that too will further maximize the frequency resonate antenna's efficiency.

However, since hams need to contend with using a wide swath of operating frequency, a resonate antenna for every operating frequency is not always possible.

So therefore we could need to conclude that if we follow the principles, theory and good engineering practices behind antenna design instead of focusing on "resonance" alone, then we will achieve real on air performance results beyond a frequency resonate antenna. In addition, the non resonate antenna also serves to function "efficiently" over a wide berth of operating frequencies.

Contrary to popular belief, resonance is not about maximizing signal efficiency. Resonance is about a load your equipment see's at a specific operating frequency.

73 de Charles - KC8VWM
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 24, 2007 Mail this to a friend!
"Basically, IMO, if you can't afford to buy coax then don't be in ham radio."

Hmm. Well, you'll catch (or ignore) enough flak for this one, so I'll keep my response collected.

The ladderline + doublet solution is a low total cost solution in time and money for a lot of hams, no matter what their financial outlay on their feedline might be.

I like K8VPL's solution just as you do. I have three antennas for eight HF bands. All are coax fed to proper matching networks at the feedpoint if needed. These matching networks are likely to exceed the efficiency of a good ham-grade autotuner.

They also took me a significant outlay of time even with software shortcuts for network and physical coil design. Mechanical assembly takes time. Building a remote switching system takes time.

I put in a lot more of my time building matching networks than it would have taken to build 50 feet of my own ladderline. I put MUCH more time in and more money, probably, than to buy a decent manual tuner and some window line.

I did it because, damn, I ***hate*** twiddling three knobs on a T-network at the radio end of a run of open wire line every time I switch bands, and I apparently like winding coils and motorizing ceramic wafer switches!

If you have two tall trees, a slingshot, and a telephone, you can have a fairly low loss variable matching network and a length of open wire line hit your doorstep and in a weekend have an antenna that will radiate a respectable signal with decent efficiency on nine HF bands, and really, the cost of the feedline hardly enters in.

There's nothing modern or progressive about using matching networks to match radiating element feedpoint impedance to 50 ohm coaxial cable, and it takes more time out of your schedule to do that than to just leave those standing waves on your feedline unless you spend significant cash on a good automatic tuner.

Would you also say that those who can't afford a 1.5kW-class automatic matching unit should also stay out of ham radio? Maybe those who can't put up an antenna that provides a suitable match to coax on each band should also stay out of radio?

I fail to see how a good manual antenna tuner + exceedingly low loss feedline under elevated SWR conditions + a single wire high in the sky is anything other than a sensible solution to quickly getting on all 9 HF bands with reasonable efficiency, a nice tidy installation, a minimal outlay of time, and a responsible outlay of cash.

It may not be completely optimum, but we're near in the neighborhood of it in the phase space of cost, frequency agility, aesthetic appeal, performance, and convenience.

Dan
 
RE: Antenna Lessons from the Old Timers  
by K5FH on May 24, 2007 Mail this to a friend!
Don,

As you have stated, and as experts such as Walt Maxwell, W2DU, have said for decades, we need to think in terms of antenna SYSTEMS.

I have always found it interesting that the 2M crowd reveres the 5/8 wavelength vertical, ignoring the fact that a 5/8 wave at resonance is nowhere near 50 ohms nonreactive. If they look closely at their commercial 5/8 wave antennas they'll find a matching network built into the base. The SYSTEM is resonant at 50 ohms; the 5/8 wavelength vertical part, taken by itself, is not.

The resonance of individual system components isn't the goal; the resonance of the entire system is.
 
Antenna Lessons from the Old Timers  
by N3JV on May 24, 2007 Mail this to a friend!
Great article with a lot of very sound advice.

I find it constantly amazing that some peope will try to find something to argue about in anything presented here, regardless of facts.

Tnka again and vy 73!

Jim, N3JV

 
Antenna Lessons from the Old Timers  
by K1CJS on May 24, 2007 Mail this to a friend!
Nice article, and good information too. To those who said co-ax is better than ladder line, to each his own. Just don't start shooting down those who have different ideas--you may (or may not, granted) find out that your conceptions aren't as good as theirs in the long run.

 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 24, 2007 Mail this to a friend!
You tell'em Dan :)
 
RE: Antenna Lessons from the Old Timers  
by N5YPJ on May 24, 2007 Mail this to a friend!
So happy to learn that real hams don't use coax exclusively, haha. Ladder line is worth the extra installation effort and way cheaper too.
 
RE: Antenna Lessons from the Old Timers  
by AD5ZC on May 24, 2007 Mail this to a friend!
Chip either got his license in a Cracker Jack box or he's a troll.

I would never...NEVER use coax (not even the kind Chip is testing in his "lab") for a single wire dipole used multi-band (didn't say fan dipole) and I can afford it gold plated.

There are many ways to run balanced feed and bring it into the shack in an acceptable manner and a simple search of the internet will reveal more than you could possibly need. Interactivity with other conductive objects and balanced feedlines has been vastly overstated in most cases and is of most concern when running significantly higher power than most rigs put out. If you do detect some RF in the shack then a little more care might be needed in the routing but thats usually not the case. I have never experienced feedline radiation with balanced line and a balanced antenna (randoms and OCF dipoles don't count folks).

Rick
AD5ZC



 
RE: Antenna Lessons from the Old Timers  
by W6TH on May 24, 2007 Mail this to a friend!
.
If you have room for a dipole, you most certainly have room for a Zepp antenna.

I have been using 600 ohm line and then 450 ohm ladder for the past 69 years and can't see any fault in its use.

My favorite antenna is the Center Fed Zepp. Remember, if the lot is too short for the flat top, you can make up the length by a longer feed line.

The center of a dipole is at 73 ohms impedance and feeding with 50 ohm coax shows a VSWR of 1.46:1.

73 divided by 50 = 1.46:1 vswr; This doesn't cause a mic to bite you, but a 5:1 will. Prune that line or go to ladder line to stop that bite. Use a transmatch, not a antenna tuner.

Very nice reading.

.:
 
Antenna Lessons from the Old Timers  
by KC9JTQ on May 24, 2007 Mail this to a friend!
I Loved the article. Some of us dont have a big yard or do want to maintain the pleasing appearance of the QTH. I have a G5RV in a sloper configuration and have worked about 30 different countries in the two months I've had HF privledges. Ham Radio is amazing and I've learned very much since I've been a Ham.
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 24, 2007 Mail this to a friend!
AD5ZC Say's
"Chip either got his license in a Cracker Jack box or he's a troll."

Aint that the truth?

Yes Chip i know aint is not a word. and i aint going to stop using it either! Real Hams use ladder line!

 
RE: Antenna Lessons from the Old Timers  
by KB5FJJ on May 24, 2007 Mail this to a friend!
I live on a 6 acre place here in New Mexico.

I built a simple 35ft tall tower using three 20-ft 2x4s.
I used a PVC elbow to make a very sturdy center conductor
and put up a 265ft balanced dipole using some scrapped wire I found. I located some cast-off 300-ohm TV-type twinlead and used that to connect the dipole to my old
MFJ-941D tuner.

I am a QRP operator mostly.
But I occasionally use an old Ten-Tec Omni V to feed this antenna with about 50watts.

But usually it is one of the following little rigs that is feeding the dipole.
Rockmites for 40,30,20
Norcal 40A
OHR 20 and 40
HiMite 20
IC-703 at 5w level with 10v in
SW+ 40 and 30

I get great results even at 400mw output with the rockmites.

I work 160mtr sideband well on quiet nights with the 703... although one operator in Phoenix quipped "Hey!
5 watts? That's illegal on 160!" :-)

Using the Omni V at 50 watts out (my little 12v supply
can only cough up 12 amps) I work mostly anyone I can hear on 160-10 meters and get great signal reports.

So... I think this article speaks the truth... I am very happy with my antenna and I have about 0 dollars
tied up in it. It is a joy to make your own antenna from scrounged 'junk' and see it work.
 
RE: Antenna Lessons from the Old Timers  
by KC8VWM on May 24, 2007 Mail this to a friend!
I am a QRP operator mostly.

-----------

Well that explains everything.

QRP'ers are experts in the area of squeezing out every ounce of RF and maximizing antenna efficiency.

Now apply those same principles QRP'ers use to your regular station and I will be the first to turn my RF gain control to preserve my hearing.

73 de Charles - KC8VWM
 
Antenna Lessons from the Old Timers  
by N0AH on May 24, 2007 Mail this to a friend!
Once again, another dipole article ignoring the requirements of height to make the antenna effective. And if you did have a high enough tower for your suggestion, a G5RV, as awful as they perform, would do as worse as your's. If you to really DX using a multiband antenna, go with a vertical with ground radials like the Hustler series anf ignore this whacko stuff. If you are a newbie, you have already been called an idiot in this article (red flag) and if you have been around for awhile, you can see the theory behind this has no real practicle application in real world installations. This is a nice cloud warmer-
 
RE: Antenna Lessons from the Old Timers  
by VK2GWK on May 25, 2007 Mail this to a friend!
Most of the negative comments on this article demonstrate absolute ignorance about antenna theory. Amazing.... how did you guys get your license? Licensing tests in the US (as the majority of the posters originate from that continent) must be pretty sloppy....

But... there is hope as the majority recognises the value of this article: KISS antenna's are the best.

 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 25, 2007 Mail this to a friend!
50 year's experince made me allergic to -

Coax
Baluns
Twin-tube amps
I use open wire line for everything - dipoles, G5RV's and boomless spider quads.

There are no short cuts to DX
Buffalo Gil W2/G3LBS
 
Antenna Lessons from the Old Timers  
by NJ6F on May 25, 2007 Mail this to a friend!
Just a few comments to counter the old timers theory on higher and bigger is better notion.

Yes I agree a G5RV is a nice general purpose antenna offering all bands with one install using a tuner and I have one for a general purpose reference antenna.

But think outside the box and make yourself a home brew Isotron without making a false analysis before you examine the goods. Look up my comments under isotron.
1500 watts into a 40 meter unit about 1 foot tall. Pictures on QRZ under my call. The 75 meter one is a little over 2 feet tall all using 4 inch PVC and 12 gauge wire solid or stranded. They really hear well and get out very well maybe being an S unit down or so from the G5RV on xmit, but FULL POWER and small size disguised as a bird feeder with superior low noise, none of that broad band noise the full size antennas exhibit and both up only 20 feet or less. I got good reports with them leaning up beside my house on the wall before putting them up. What could be better. Worked a UA0 on the 75 meter home brew isotron. No, your wrong again, it is tunable across the entire phone band and one coax to both 40 and 75 homebrew isotrons does the trick. I have a 160 version only 9 feet tall and performs excellant at 3 feet above a metal fence...sorry again, more height results in less performance for this one band.

Another last comment- AEA Isoloop standing (vertical) just 3 or 4 feet off the ground is as good as a full sized dipole at 30 feet or so. NO, height does not make a difference with that 3 foot 10-30 meter tunable loop and less noise than all these full sized wire antennas vertical or horizontal. I have the room but like the smaller antennas and get a kick out of the comments after I get a wonderful signal report, telling them it is a 1 foot tall antenna they go UH....because most are conditioned to higher and bigger is better. Or another precondioned response...you poor guy, you must not have any land, I have no problem with land.
I would go for a full size loop with lots of space probably due again to lower noise and nice gain. They are easier to point than a beam and do not require the height. How can that be....you must have height they say...bull. Time to load up that fence.

Another crazy assumption is that you have to be in front of the radio to have fun instead of enjoying the sun out at the pool. I use a Kenwood phone patch and a cheap Radio Shack 900 Mhz hands free headset phone with dual head phone/boom mike,with FT100D / amp, and had a nice chat with a group of my friends and a guy in France in VOX mode. Hey, another boring roll call or net... lock the rig on frequency and enjoy the outdoors. If it is always crappy outside, move.

I just wanted to help by passing on some info you can use to make an educated decision if in close quarters or you would like to keep your neighbors happy by not turning your available land into some overly ugly antenna mess.
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
--I did credit www.w7fg.com (who sells excellent open-wire feedline and complete antennas at a price at which he could not be making much of a profit) for the photo in the original draft of the article but the text somehow got lost in the upload of the manuscript
------------


Then fix it.

And while you're at it, get another photo. The one you show IS DANGEROUS to NEWBIES, because it advocates running ladder line in virtual contact with the upper section of a metal tower. That poses a real danger for electrocution and/or fire.

SWITCH TO SAFETY.

Switch to coax.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
Most of the negative comments on this article demonstrate absolute ignorance about antenna theory. Amazing.... how did you guys get your license? Licensing tests in the US (as the majority of the posters originate from that continent) must be pretty sloppy.... VK2GWK
----------------------------------------

Kindly show how my comments are indicative of an "absolute ignorance of antenna theory".

FYI, I got my license by working hard and becoming something better than I was. My son's school--which has a great ham station BTW--has a motto that resonates with that: 'our best today, a better tomorrow'.

Hey, in fact that's how I ended up getting a Ph.D.; creating a new antenna technology; living the American dream; and helping others in the process.

Among other things.

But, I digress: I see you are not an American and these values may be unknown to you.

73,
Chip W1YW

 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
Chip either got his license in a Cracker Jack box or he's a troll.

-------------------------------------------

Sorry that your limited perspective forces you to see things in binary terms--each of which are wrong.

Pity.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
But... there is hope as the majority recognises the value of this article: KISS antenna's are the best.

=======================================

Do you also advocate attaching ladder line in virtual contact with a metal tower?

Well, from a KISS standpoint, one may certainly agree on the 'stupid' part....

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by KC5CQD on May 25, 2007 Mail this to a friend!
Kindly show how my comments are indicative of an "absolute ignorance of antenna theory".

"FYI, I got my license by working hard and becoming something better than I was. My son's school--which has a great ham station BTW--has a motto that resonates with that: 'our best today, a better tomorrow'.

Hey, in fact that's how I ended up getting a Ph.D.; creating a new antenna technology; living the American dream; and helping others in the process.

Among other things.

But, I digress: I see you are not an American and these values may be unknown to you.

73,
Chip W1YW"



Whoah!! Now THAT was a zinger! hihi!
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 25, 2007 Mail this to a friend!
Congrats Skippy, you finally got someone to bite!
 
RE: Antenna Lessons from the Old Timers  
by K0RFD on May 25, 2007 Mail this to a friend!
W1YW wrote:
>each of which are wrong

While we're criticizing just for the sake of criticizing (see the fourth comment in this thread):

"Each" is singular. "Are" is plural.

Perhaps you meant "both of which are wrong?"
Or maybe "each of which is wrong?"
 
RE: Antenna Lessons from the Old Timers  
by N9XY on May 25, 2007 Mail this to a friend!
I somtimes wonder if all the ranting and raving when it comes to the subject of antennas isn't really just a case of sour grapes?

Those who have spent lots of $$$ and time on towers, beams, expensive hardline coax, linear amplifiers, "phased vertical" arrays covering acres of real estate, etc. freak out when the rest of us insist that we can work anywhere in the world with just 100 watts (or less) and a cheap antenna coupler and ladder line fed wire in the trees.

73
Michael
N9XY
 
RE: Antenna Lessons from the Old Timers  
by WB4TJH on May 25, 2007 Mail this to a friend!
Great article! I have been using this antenna system for most of the 38 years I have been on the air. The only difference in my system now is that I use an Alpha Delta 80-40 shortened dipole that I feed with 300 ohm windownline instead of 450. The balun is a 1:1 balun made by DX Engineering and there is a 6 foot piece of coax thru the wall of the house to my tuner. It works very well on all bands from 80-10. I have NO complaints.
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 25, 2007 Mail this to a friend!
"it was made from 1/2 inch ridged copper water pipe. It was some 100 feet long, most of which ran up the side of a telephone pole to his extended zepp. The spreaders were made from soft pine, and paraffin soaked. It took him about 6 months to build."

Impressive! But IMHO somewhat poorly engineered.

The improvement gained by the use of half-inch rigid copper pipe over, say, #12 copper wire, for 100 feet of HF open line, is so small as to not be worth all the work. IMHO, much more would have been gained by
using better insulators.

"The question remains, why don't amateur do this sort of thing today?"

Some amateurs do! The ladder line in the picture is home-made. Google my call and see another example of
what can be done at home. My antennas are all homebrew, too.

"Well, its because everyone seemingly is into instant gratification nowadays. So, it's why build what you can buy."

That's true in some cases. But there are other factors.

One is that the inflation-adjusted cost of amateur radio today is lower than it was in the bad old days.

Another is that the total cost savings of DIY aren't
always that great, unless you count your time as free and can get parts and supplies at a big discount.

There's also the fact that we have choices today that
did not exist in the past.

"We are (and have) diminished."

Well, I don't feel diminished at all.

But consider this:

There was a time when, if someone wanted to be a ham,
they needed a considerable amount of technical know-how. Not just to pass the test, but to get a station on the air.

Improvements in technology have changed what a ham
needs to know in order to get a station on the air.

For example, in the bad old days, a ham who used coax feedline had to either learn how to solder connectors on it, or had to get somebody else nearby to do it for him/her.

Nowadays, we can buy complete coax assemblies with the connectors already attached, and/or crimp-on connectors and tools. For some hams, it's easier, faster and *cheaper* to go ready-made - so they do.

73 de Jim, N2EY




 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 25, 2007 Mail this to a friend!
"Don't use ladder line. Ever."

Why not?

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by N2EY on May 25, 2007 Mail this to a friend!
Good article, with one BIG caveat: the balun issue.

For certain combinations of antenna and feeder length, the impedance presented at the shack-end of the ladder line can be very high, very low, and/or very reactive.

But most baluns, be they "current baluns" or "voltage baluns", are designed for a relatively narrow range
of impedances. Outside that range, they can exhibit all kinds of odd behaviors.

"Smoke and flames" is a worst-case scenario, and is not a foolproof indicator. For example, if you run QRP, your balun can be very lossy, yet there just
isn't enough power to fry the balun even if it dissipates 99% of the RF.

Or, the balun may not be doing the balanced-to-unbalanced job, and you can actually be feeding
the system as a sort of vertical worked against ground.

The fact that it "works great" isn't always a clear indicator. Hams work the world with QRP, so if the tuner/balun combo dissipates, say, 90% of your rig's 100W output, you're still radiating 10 watts.

It's also possible that your particular choice of feedline and antenna lengths do not present really wild impedances to the tuner.

Best bet IMHO is to use modeling software and be sure.

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
You have:

1)ladder line for QRO...
running parallel and virtually in contact with..
2)metal tower in the ground.

Now either the practical issues of avoiding electrocution and/or fire should be thrown out the window, or we need to get the author to amend this article, so as to prevent accidents from non-'old timers'.

If you think that's trolling then think. Period.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
Best bet IMHO is to use modeling software and be sure.

73 de Jim, N2EY

--------------------------

If you feel that you can model the mutual coupling between ladder line and (order) millimeter separation from a metal tower--then please do so! You will see exactly how dangerous it is to have ladder line routed as shown in this article's picture.

Do anything that convinces others of the hazard of said situation. Don't care how others also reach that conclusion, as long as they get there.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
W1YW wrote:
>each of which are wrong

While we're criticizing just for the sake of criticizing (see the fourth comment in this thread):

"Each" is singular. "Are" is plural.

Perhaps you meant "both of which are wrong?"
Or maybe "each of which is wrong?"

-------------------------------------

You obviously fail to appreciate the subtlety of my humor...
 
RE: Antenna Lessons from the Old Timers  
by AK2B on May 25, 2007 Mail this to a friend!
Don, this is a very nice article both for its intended audience and the rest of us who found it entertaining. Thanks.

To the new hams that might be reading the negative comments here, be aware that there are plenty of angry hams among us who don’t hesitate to dump their empty thoughts without the slightest regard for the truth or their impact on our community. Fortunately, there are several others who are more than willing to add something to the hobby by sharing their knowledge and wisdom.

Building antennas is one of the easiest ways to start experimenting without a great deal of money or experience. I would suggest everyone try making their own simple wire antennas to start. You will be surprised how easy it is to duplicate, with excellent results, antennas made up of very simple components. I’ve made several antennas using Radio Shack twin lead, a few insulators and some wire. As mentioned, W4RNL (I refer to him as St. Cebik) has several interesting antennas to try. Take a look at http://www.cebik.com/fdim/fdim9.pdf for an article called “My Top Five Backyard Multi-Band Wire HF Antennas”. Another favorite of mine is http://www.cebik.com/edz/aledz.html “Suppose I could have only One Wire Antenna…” These articles may be too technical for some, but the information is there to enable construction of any of the antennas mentioned. Eventually, you may find the subject as fascinating as many of your fellow amateurs and investigate further into the theory behind them.

Tom, AK2B
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
Hi Tom,

I do feel that your advocation of this article is inappropriate as advice to newbies. There are several reasons, but here are the two overriding ones:

First, the photo so shown indicates a virtual touching of ladder line to a metal tower. This poses a safety hazard for electrocution and/or fire.

Second there is NO discussion at ALL about lightning protection. This is a major problem with ladder line, and although home-brew 'lightning breaks' are possible, few take the time to make them, and to make them low-loss. (Lightning arrestors for coax are on off-the shelf-item).

Perhaps when ladder line enthusiasts admit and convey these admonishments to 'newbies' we can then continue the value, or lack of it, of ladder line overall.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
W1YW seems aghast at: "1)ladder line for QRO...
running parallel and virtually in contact with..
2)metal tower in the ground. "

Chip, I think you need to get some perspective... I mean, quite literally, a reread of visual perspective in that photo. According to w7fg.net that's a 75 foot tower.

Where do you get that the ladder line comes near that tower on the order of 1mm? I bet it's order(2 inches) up near the top of the tower...

Similarly, the ground isn't even in the photo...

To quote: "If you feel that you can model the mutual coupling between ladder line and (order) millimeter separation from a metal tower--then please do so! You will see exactly how dangerous it is to have ladder line routed as shown in this article's picture. "

Order (1mm) seperation could arc like an SOB. You'll get a few kilovolts going up there on some bands... big deal. Take the spacing out to a couple of inches (like it is) and you're done.

You talk about fire hazard when you imagine ladderline with sparse plastic spacers run very close to galvanized steel. Neither copper wire nor galvanized steel are particularly likely to be ignited by an arc. If you've got a spacer right there, it'll go up. Big deal. They're too far apart for the fire to spread.

Let's look at another scenario, one far more stupid and dangerous. You've got your random doublet at the top of your tower. You've got your whiz-bang tuner that can handle 1500W into anything in a 5000 ohm radius circle in the complex plane... and instead of using open wire line, you use RG-8X coax...

Not only do you use RG-8X coax, but you used RG-8X coax because "it was easy to route through the walls".

I do believe a sustained RF arc carrying 1500W through polyethylene foam will start a real fire... and in my concocted example, it will be one in the walls of your house, not one 75 feet up on your tower that doesn't have anywhere to go.

- - - - - -

The point is, we need to have a healthy respect for 1500W of radio frequency energy no matter what line is carrying it. I think inexperienced hams are *scared* of ladderline, rather than appropriately cautious. They're also not experts in feedline systems.

It's far more dangerous to put up a random dipole fed with RG-8X and then to decide that since no one can hear you, you'll buy an amp.

Much safer to run 100W into open wire and make lots of good contacts.

If smart guys like you would be more willing to share your knowledge with the newbies instead of tersely voicing weird objections to others' advice, this would be a positive step toward better, safer antenna systems for the inexperienced ham.

What did open wire line do to you?
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"Second there is NO discussion at ALL about lightning protection."

A legitimate concern... but one equally true of casual antenna installations with coaxial feedline.

Dan
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
Chip, I think you need to get some perspective... I mean, quite literally, a reread of visual perspective in that photo. According to w7fg.net that's a 75 foot tower.

Where do you get that the ladder line comes near that tower on the order of 1mm? I bet it's order(2 inches) up near the top of the tower...

Similarly, the ground isn't even in the photo...

To quote: "If you feel that you can model the mutual coupling between ladder line and (order) millimeter separation from a metal tower--then please do so! You will see exactly how dangerous it is to have ladder line routed as shown in this article's picture. "

Order (1mm) seperation could arc like an SOB. You'll get a few kilovolts going up there on some bands... big deal. Take the spacing out to a couple of inches (like it is) and you're done.

You talk about fire hazard when you imagine ladderline with sparse plastic spacers run very close to galvanized steel. Neither copper wire nor galvanized steel are particularly likely to be ignited by an arc. If you've got a spacer right there, it'll go up. Big deal. They're too far apart for the fire to spread.

Let's look at another scenario, one far more stupid and dangerous. You've got your random doublet at the top of your tower. You've got your whiz-bang tuner that can handle 1500W into anything in a 5000 ohm radius circle in the complex plane... and instead of using open wire line, you use RG-8X coax...

Not only do you use RG-8X coax, but you used RG-8X coax because "it was easy to route through the walls".

I do believe a sustained RF arc carrying 1500W through polyethylene foam will start a real fire... and in my concocted example, it will be one in the walls of your house, not one 75 feet up on your tower that doesn't have anywhere to go
-------------------------------------

Finally some real beef...

First, order means order of magnitude. The picture certainly has the ladder line virtually touching the metal tower at the top. Do you dispute this? Do you dispute this is dangerous?

Second, I am aware that there is a '2 inch' rule of thumb floating amongst hams. I am here to tell you right now that it is frequency dependent and that I have actually seen arcing at 2 inches (35 years ago). So if you're asking a practical separation away from the tower, six inches at HF/MF is reasonable. Two inches is not. NO SPACER's used in SEPARATION is damn damgerous. And that's what the picture shows.

So why isn't this in the article? Saftey issue should be up front and OBVIOUS in ANY article about ladder line--especially to those who haven't used it.

Finally, who the heck said that the fire hazard was to galvanized steel?! Newbies have to be told that generating ANY ARC is dangerous and poses a fire hazard. Get real.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
"Second there is NO discussion at ALL about lightning protection."

A legitimate concern... but one equally true of casual antenna installations with coaxial feedline.

Dan


-----------------
Well Dan, there's a reason why coaxial lightning arrestors are an off-the shelf item. You'll find them on the shelf right next to the shiny coils of coax at the store.

GL finding lightning breaks for ladder line. Or making ones with consistently low-loss.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
What did open wire line do to you?

--------------------------------------
Dan, that's just plain goofy.

Why is it that when someone legitimately criticizes the advice from an ARTICLE that the attack is levied on the MESSENGER?

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"I am here to tell you right now that it is frequency dependent and that I have actually seen arcing at 2 inches (35 years ago)"

I'll buy that. I don't have the breakdown voltage of outside air across MF/HF or the maximum possible voltage present on ladderline for all possible antenna and line length combinations memorized... let's run it out to 6 inches. Of course, 2 inches was 50x your guess, and we've only added a safety factor of three...

"NO SPACER's used in SEPARATION is damn damgerous"

I gather from that picture that the feedline is hanging between the feedpoint and a far distant point from the tower. Two inches was my guess for the feedpoint closest approach. It *looks* like it's coming straight down because of the perspective, but I bet it's three feet away or more at the rotor bracket there.

Some positive steps to keep the ladderline spaced from the tower is good advice, but the real danger is to your amplifier, not a fire danger, which brings us to:

"Newbies have to be told that generating ANY ARC is dangerous and poses a fire hazard. Get real. "

People need to be able to do realistic risk assessments on a day to day basis to avoid being paralyzed by fear.

An arc between a bare copper wire and a tower up at 75 feet is not a legitimate risk. What's going to happen? Maybe you get a little plasma ring vortex that manages to hold on to enough heat during it's 75 foot fall to ignite your shingl... oh wait... hot plasma... sounds like something that's probably less dense than the surrounding air.

Ok... molten copper? Maybe, but you'd have to load your amplifier into the arc and leave the key down for that to happen. The SWR-obsessed new ham is going to notice when the SWR needle spikes all the way up on voice peaks, and is going to try to figure out the problem.

Drawing a few arcs from your feedline because something went wrong is not the end of the world, unless it's to you, your house, or your kids.

Dan
 
Antenna Lessons from the Old Timers  
by N4VNZ on May 25, 2007 Mail this to a friend!
RG8X at 1500 watts is going to melt and possibly ignite. RG8U will take more abuse, but even then it will fail if heated sufficiently.

Newbies, 8X is suitable for mobile installations at low power levels and for home use at power levels up to a few hundred watts or so, maybe more IF the SWR is kept within a reasonable range. Places like Copper Electronics will say that 8X is good up to a KW, but I would not rely on that advice. QRO operation requires good quality RG8U or hardline AND some attention to the SWR that the line will see, especially if you intend to run high duty cycle modes. If you are burning up the centers of pl 259 connectors regularly then you might consider switching to open wire feeders. Fire hazard is a real concern, and nothing is more inconvienient than having to interupt a QSO to go put out a grass fire. (insert obligatory smiley here). I have seen it happen!

I think that people that have not had great experience with high RF voltages may tend to ignore or minimize the danger of this type of energy. I gained a heathy respect back a few years ago for high voltage through a nylon screwdriver whilst neutralizing a set of tubes in an FT 101. Yes, RF will travel right up that nylon screwdriver. Unfortunately, RF will getcha even if you are not in direct contact with the conductor. I remember getting a nasty RF burn from accidentally holding a pl 259 on the end of a piece of coax connected to an antenna that was not being used at the time but was in close proximity to another antenna being used on a HF packet forwarding station running a KW.

QRO is fun, but beware the Hammer of Thor...

73,

N4VNZ
 
Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Great article Don ! Having lived in the South and off the air for the past 7 years, I understand your point of view and appreciate your humor. Having moved back up North, I am again becoming active, and the antenna system is of course the PRIMARY concern, because I sill have all my other goo (tranceivers, amplifiers, speakers and microphones, cup holders).

I have become interested in parallel transmission line to overcome the anticipated losses in 300 to 400 feet of feedline to where she says I may install antennas. Having spent a large gob of money on amplifiers, I dont want to waste my precious watts. My latest experiment with the 2 conductor stuff was to use the barn, a steel building with a metal roof. I connected one conductor to the walls of the barn, and the other conductor to the roof. I think I have unbalanced the line, because the goats seem figity when I transmit qro very wide mode (cw doesnt seem to bother them, probably because I am so slow), and the lights flicker. Any suggestions on how to cheap and easy determine line balance ?

Thanks,
Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by AK2B on May 25, 2007 Mail this to a friend!
Chip,

It seems impossible to tell from this photograph that the ladder line is touching the tower for two reasons.
1. It’s a photograph! From the angle which it is taken it is not possible to judge the distance of the ladder line from the tower. Photographs greatly exaggerate perspective by bringing the foreground and the background to the same plain – particularly at that distance.
2. I can’t imagine that the ham who constructed this antenna would be so shallow as to let the ladder line short against the tower.
I don’t think the article was meant to cover every imaginable aspect of antennas but simply to explain to the newcomer other possibilities than coax fed antennas. Lightening protection is complex enough that it could be the subject of another article all by itself. Geez, back off and give Don some credit.

Tom, AK2B
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"Dan, that's just plain goofy.

Why is it that when someone legitimately criticizes the advice from an ARTICLE that the attack is levied on the MESSENGER? "

Could be that you came in being goofy as well:

You said: "Don't use ladder line. Ever.

If you operate in a way that REQUIRES ladder line, then consider giving up ham radio and playing character roles at Medeival festivals. "

You've certainly tempered and focused your objections into the technical since then, so let's keep going that way... much more productive for everyone.

"Well Dan, there's a reason why coaxial lightning arrestors are an off-the shelf item. You'll find them on the shelf right next to the shiny coils of coax at the store. "

Coaxial lightning arrestors are only as good at protecting your house from a lightning strike as your ground system is. Grounding your coax shield well at the entrance to the house and grounding any tall metallic supports properly is far more important than the arrestors.

I think that new hams should be concerned with their families, the neighbor kids, their pets, their houses... and way down on the list somewhere should be their radio gear.

So, lightning arrestors are a red herring, but grounding your coax shield is very important (and required by many localities who adopt NEC language into their electrical codes, I'm sure). You can't do that with ladder line.

I would personally recommend a remote tuner in an outdoor enclosure with the case grounded to a really good earth ground. Put a nice fence around it to keep the neighbor kids away from the HV.

However, lightning protection was hardly your original objection... and also, lightning protection is hardly something that is well executed at the average ham station, so I might claim that it's really beyond the scope of this article.

Dan
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
SAFETY should not be an aside for the advanced only. It should be upfront for the newbie.

The fact is that, among other things, ladder line is dangerous unless these two safety issues are addressed.

Your trivilization of that concern goes against the very code of the Radio Amateur,IMO.

Stop worrying about who said it and worry about the fact that it remained unsaid--if someone else had said it I certainly would not.

Frankly, given that this article is 'lessons learned from OLD TIMERS', one should WELCOME another OT pointing out these compelling concerns.

Or do you dispute that I am an OT?

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
You said: "Don't use ladder line. Ever.

If you operate in a way that REQUIRES ladder line, then consider giving up ham radio and playing character roles at Medeival festivals"
--------------------------------
I did. I mean it, too.

Ladder line is an antiquated feed system. No concern that ladder line supposedly addresses is not long-since solved by coaxial- based antenna systems.

If someone put on their resume that they have ladder line (required) antennas I would not hire them.

FYI.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Chip,

I dont dispute your status as an OT. I suspect there may even be some dust in your spark gap.

Ron
KB8ELK
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
I'm sure there would be if I had one. But I don't.

The point? Not all OT's are ossified (look that up).

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Ossified ? You have health problems also ? Sorry to here that. I think ladder line has it's place, and I am enjoying playing with it (guess I wont be working for you). However, I am looking work a "simple" method to measure line balance. I have tried wetting my fingers and running them up and down the feedline while transmitting, and the one side does seem to tingle more than the other, but that may be due to a callous on my thumb. It is interesting that you can tell when you approach a 1/4 wavelength spot though.

Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"Or do you dispute that I am an OT?"

From QRZ: "WN1HBX 1966" - nope, that's a fine tenure as a ham. OT status confirmed. I, of course, am not an OT.

And

"No concern that ladder line supposedly addresses is not long-since solved by coaxial- based antenna systems. "

Well, you're less antiquated than coaxial cable...

My point in a post that didn't seem to trip your radar was that from a total cost perspective, are not necessarily the most economical and attractive proposition for today's ham attempting to radiate an effective signal on 9 MF/HF bands.

Let's assume we're trying to feed the same radiator to with the same radiation efficiency. We can pick either coaxial cable and a remote matching unit or an indoor matching unit and ladder line. For a given radiator and efficiency, I'm sure that the total cost in time plus money is less for the latter solution. Additionally, we shouldn't pretend that matching networks at the antenna to allow the efficient use of coaxial cable on a nonresonant, non-50 ohm radiator are shiny new technology. WWII, dude.

I *personally* favor that approach, but it's hardly forward-looking. It's also generally either complicated or expensive.

Dan
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"from a total cost perspective, are not necessarily the most economical and attractive proposition"

Should have a "coaxial-based antenna systems" in it somewhere.
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on May 25, 2007 Mail this to a friend!

Lightning protection is obviously worthwhile, but the discussion has once again gone way off the deep end and deviated into a separate subject.


It would seem that some of us are not satisfied with the topic at hand and must rip the guts out of it so we can find something to be self-righteous about.


Why oh why Sigmund does this happen??


....WA1RNE
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
Also :

"If someone put on their resume that they have ladder line (required) antennas I would not hire them."

Seems sensible. Someone who puts that level of detail about their hobby into their resume is probably trying to pad it a bit ;-)

Dan
 
Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Okay, back on target : Short of buying an rf ampmeter, anyone have a practical cheap n' dirty way to determine if the lines are in balance ? couple scope probes near the feedline ? Calibration seems worrisome. Neon bulb ? Even I, at my tender age, will agree that seems antiquated.

Maybe assume line balance by determining minimal feedline radiation ?

Scope the voltage drop across resistors in the line ?

Ideas ?

Ron
KB8ELK
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
"Or do you dispute that I am an OT?"

From QRZ: "WN1HBX 1966" - nope, that's a fine tenure as a ham. OT status confirmed. I, of course, am not an OT. --N3OX

-------------------------------

Hi Dan,

I know that the notion of 'time' is a confusing one, but in English we have a convention. That convention relates to present TENSE to represent PRESENT; past TENSE to indicate in the PAST; and so on.

I am 100% certain that at some PAST TIME I would not have been considered an OLD TIMER.

I asked you if YOU DISPUTE --as in the PRESENT--that with my 41st year in ham radio I am (that's present tense, now) an OT.

I do not dispute that I am an OT.

Don't get goofy. Or, as Herman Hesse said in 'Demian':"Don't talk sh*t, young man".

Who am I to argue?

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by KB0LPI on May 25, 2007 Mail this to a friend!
KB8ELK,

Don't know if it qualifies as cheap, but this would be an easy way to determine line balance:

http://www.mfjenterprises.com/products.php?prodid=MFJ-835

KB0LPI
Eric
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
Let's assume we're trying to feed the same radiator to with the same radiation efficiency. We can pick either coaxial cable and a remote matching unit or an indoor matching unit and ladder line. For a given radiator and efficiency, I'm sure that the total cost in time plus money is less for the latter solution. Additionally, we shouldn't pretend that matching networks at the antenna to allow the efficient use of coaxial cable on a nonresonant, non-50 ohm radiator are shiny new technology. WWII, dude.
--------------------------------

Why are you so sure? And why do you need some stupid switching unit?

I also wouldn't hire anyone who made assumptions like that. Too hard to re-educate them.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"Why oh why Sigmund does this happen?? "

Freudian analysis is outmoded. Let's....

Oh, right.. ham radio forum ;-)

You can't stop the freight train. Like Don said, straight up, this is one of the most contentious topics out there.

The general reason would appear to be that line loss and resonance issues are not really a matter of opinion, and yet many have a strong opinion on the matter.
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
KB0LPI

Thanks ! I did not even think to check MFJ, guess I was stuck in homebrew mode. The MFJ-835 looks like the ideal solution if it performs well. There are no eham reviews on it (yet), does anyone have any experience with it ?

Ron
KB8ELK
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
So, in that case, here is a piece of great wisdom.

Wait for it...

It's that important.

Here it is...

The second you think someone can't do something, watch out for those who quietly make money from proving you are wrong.

Live by that and you will flourish in the (otherwise) 'den of iniquity' known as the antenna world...

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"And why do you need some stupid switching unit? "

You don't, but you're not going to tell us your particular easily implementable and clever ideas, so that's also a red herring. Many hams start from little to no techical background. Even those with major technical background have little in the way of analog electronics experience.

By the way, if you're talking in particular about my networks, I couldn't possibly have done that more stupidly or inefficiently in terms of resource usage and mechanical design. I wanted a simple decoupled system so that I could do what I wanted to do and also have an easily reproducible system for hams who might want to build part of it.

I mean, what kind of backwards idiot uses an ALL ANALOG proportional controller to turn a CERAMIC WAFER SWITCH?

... except that lots of hams have ceramic wafer switches that need turning from 150 feet away and will back down from any but the simplest homebrew electronics projects.

"I also wouldn't hire anyone who made assumptions like that"

Don't know why you keep mentioning who you won't hire. I doubt there are many in here who would be looking to work for you.

Dan
 
RE: Antenna Lessons from the Old Timers  
by W7COM on May 25, 2007 Mail this to a friend!
Thanks for the wonderful (and I mean full of wonder of what I can build) article. I'm new to HF and have lived the coax route for over a decade on V/UHF. Now you've got me wandering around the lot looking up! Also thanks to the kind responders for the links. They will keep me busy for many happy hours wondering what I'll first build. And isn't that at least half the fun of ham radio?
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Hmmm, dont know about that, but I have an answer to my question and I'm satisfied.

If you have an interest in homilies, here's one of my favorites (from The Princess Bride) :

"Life is pain. Anyone who tells you different is either lying or trying to sell you something."

Ron
KB8ELK
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
You don't, but you're not going to tell us your particular easily implementable and clever ideas, so that's also a red herring.

---------------------------------
No; it's reality.

So, young man, find me a way to convey this to hams only and you're on.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
"I also wouldn't hire anyone who made assumptions like that"

Don't know why you keep mentioning who you won't hire. I doubt there are many in here who would be looking to work for you.

Dan

-------------------------------------
Seems to me that it would be easy to ignore if you didn't find it of interest....
 
Antenna Lessons from the Old Timers  
by KE4ZHN on May 25, 2007 Mail this to a friend!
Thanks for a nice article Don. I love my W7FG 600 ohm open wire fed doublet and will continue to use and enjoy it on 6-80 mtrs. Some folks have heads like bricks and refuse to accept the fact that a non res antenna system can work but thats fine with me. Let them sweat in the hot sun cutting and trimming while I work DX in the nice cool AC.
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Chip,

How many ways can you be wrong ?

I was ASKING (ie seeking) for a solution. I have one now, before I had none.

I recited a line from a movie, dont argue with me, I got the line correct. Argue with the movie.

You refer to me as young man ? Younger than you ? With your mere 41 years in ham radio, licensed in 1967 at age 11 ? Perhaps math is not your best subject. My first call was WA8DRB, 1962, age 12 (slacker I know).

Sending my resume to Dan.
Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"The second you think someone can't do something, watch out for those who quietly make money from proving you are wrong. "

Are you talking to me or just in general? If the former, are you assuming that I'm assuming that a particular matching task can't be done?

I'm sure that you have all manner of clever solutions to all manner of antenna design problems. I also know they will never see the light of day in hams' backyards because of the statement above.

Every time I look at Fractal Antenna Systems' homepage, it looks like the company is enjoying continued success, congratulations. I doubt it's any more likely that you'll start building ham antennas or providing ham antenna information than it is likely that I'll build a synthetic aperature HF antenna in my rental backyard.

Dan
 
Antenna Lessons from the Old Timers  
by KB7XU on May 25, 2007 Mail this to a friend!
For the author: Thank you, Don, for taking the time to write a most interesting, well-written article. Good writing looks like a simple thing to do but only skillful wordsmiths can do it.

As for the content, I suspect "Kurt N. Sturba" of World Radio Magazine would approve. And so do I.
Max, KB7XU
 
Antenna Lessons from the Old Timers  
by N4VNZ on May 25, 2007 Mail this to a friend!
Hey Don,

Dreamland has the best barbecue in Alabama.

As far as football goes, does either Auburn or Alabama pursue that pastime anymore?

I worked in North Alabama (Huntsville) for about 10 years way back so I have heard it all.

73, Boog
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 25, 2007 Mail this to a friend!
Oh i love it when Chip preaches. Lets have a show of hands who really gives a sh!t what he has to say however. You go Dan.
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 25, 2007 Mail this to a friend!
W1YW wrote:

"Don't use ladder line. Ever."

Why not?

"If you operate in a way that REQUIRES ladder line, then consider giving up ham radio and playing character roles at Medeival festivals"

Why?

--------------------------------
"I did. I mean it, too.

Ladder line is an antiquated feed system."

So what? Old doesn't mean bad.

How old is the three-wire 120/240 volt electrical system most Americans use in homes and small businesses?

How old is the Otto-cycle internal combustion engine?

Is SSB antiquated? It was first used on radio in the 1920s, and first used by hams in the 1930s.

"No concern that ladder line supposedly addresses is not long-since solved by coaxial- based antenna systems."

Here's a concern:

A residence near me consists of a lot that's 150 feet square, with the house near the center and trees near the border. The trees are nice big maples and oaks, and it would be a simple matter to use two of them to hold a classic 80 meter center fed dipole 50 to 70 feet in the air, with the feedline hanging straight down.

With a little thought, the feedline could be routed vertically along the back wall of the house to a basement window and into the basement hamshack.

Consisting of just a simple dipole, ladder-line feed, a good *balanced* tuner, and judicious choice of dipole and feedline lengths, such an antenna system would be capable of excellent results *and* 1:1 SWR to the rig on all ham bands 80 through 10, and probably 160 as well. It would also be good on MARS frequencies and for SWLing.

It could be quite inexpensive if the tuner, antenna and feedline were homebrewed.

No tower, no masts, no guy wires, no extensive radial system, not very visible if the ladder line is made with some thought, no building permits, no variances, no climbing, very little maintenance. Done right, the neighbors wouldn't even know it was there unless you pointed it out.

btw, this isn't a one-of-a-kind residence. There are lots of them around here.

What coax-fed antenna of comparable performance, price and simplicity could be installed at that QTH which would have all those features?

Let's see:

Multi-parallel dipole? Mechanically complex and a lot of adjustment. Plus the SWR varies across the band unless a tuner is used.

Trap dipole? Electrically complex and a lot of adjustments if all HF bands are to be covered. Plus the SWR varies across the band unless a tuner is used.

T2FD? Mechanically complex and electrically inefficient over much of the range.

G5RV? Doesn't cover all HF bands without a tuner, and it has some ladder line anyway. Plus the SWR varies across the band unless a tuner is used.

OCF dipole? Not fed in the center, lots of adjustments, and electrically complex if all bands are to be covered. Plus the SWR varies, etc.

Loop skywire? Requires 4 supports instead of 2, and the feedpoint is at the edge, not the center. Plus it usually needs a tuner.

Lattin stub-decoupled dipole? Similar problems to a trap dipole.

W9INN dipole? Not made anymore, and in any event it's a cross between a parallel dipole and a trap dipole.

"If someone put on their resume that they have ladder line (required) antennas I would not hire them."

Why not? Is there absolutely *no* imaginable scenario where a ladder-line-fed antenna could be a better overall solution than a coax-fed antenna?

73 de Jim, N2EY

 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 25, 2007 Mail this to a friend!
"Some folks have heads like bricks and refuse to accept the fact that a non res antenna system can work but thats fine with me."

But your system (W7FG ladder-line fed dipole w/tuner) *is* resonant! Maybe the antenna wire itself isn't resonant on all bands all by itself, but the entire *system* (dipole, feedline, tuner) *is* resonant at the operating frequency.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
Hmmm, is this a true statement : Most ham antennas are operated in a non-resonant manner.

I think mine are. Never really on that one spot where Xc and Xl are equal. Never had a 50 ohm feedpoint either.

Food for thought.

Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"So, young man, find me a way to convey this to hams only and you're on. "

You can't keep it under wraps if you sell it as a ham product or disseminate the information. I understand your position as an innovator with a great deal of intellectual property to protect. However, it's silly to claim that ham approaches are outdated compared to your approaches when you and I both know that you must keep that information secret for the health of your business.

What would you do if I published construction details of a particular self-similar copper wire object that, when placed in the middle of a wire doublet, effected an impedance transformation to 50 ohms over a large continuous swath of HF? What if I publicized an independently developed algorithm to generically design such an object? I'm not saying that I can figure it out, but even if I thought I could, I would be concerned for my legal position.

The open wire fed doublet: antiquated, maybe. Effective? Effective enough. In the public domain? Surely.

- - - - - -

As far as desire to be in your employ:

"Seems to me that it would be easy to ignore if you didn't find it of interest...."

I simply find it of interest that you bring it up out of nowhere as a valid measure of intelligence and engineering skill.

I also figure, in for a penny, in for a pound... might as well hit all the points I want to hit at this stage in the game. Generally, I'm happy to let others worry about your comments. I've got my reasons for responding this time. That's just the way teh intarweb works, d00d.

73,
Dan



 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
As far as desire to be in your employ:

"Seems to me that it would be easy to ignore if you didn't find it of interest...."

I simply find it of interest that you bring it up out of nowhere as a valid measure of intelligence and engineering skill.

I also figure, in for a penny, in for a pound... might as well hit all the points I want to hit at this stage in the game. Generally, I'm happy to let others worry about your comments. I've got my reasons for responding this time. That's just the way teh intarweb works, d00d.


73,
Dan

----------------------------------

Again,seems to me that it would be easy to ignore if you didn't find it of interest...

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by KB2HSH on May 25, 2007 Mail this to a friend!
I have used 450-ohm ladder line on all of my antennae since 1997...and I wouldn't ever go back to coax. I don't want to cause any trouble, but I have had better success with a ladder-line fed 300 foot loop than with any other antenna I have ever used. And to top it all off, my tuner is NOTHING more than an MFJ-941E (not the best tuner, but it has worked flawlessly since 1993).

To each his or her own...I always say.

Have a Great Holiday Everyone!

73 de KB2HSH
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
KB2HSH,

Have you ever been concerned about the balance of the line, or had reason to suspect it was unbalanced ?

My lack of experience here shows, am I obsessing ?

Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by WB2WIK on May 25, 2007 Mail this to a friend!
>RE: Antenna Lessons from the Old Timers Reply
by KB8ELK on May 25, 2007 Mail this to a friend!
KB2HSH,

Have you ever been concerned about the balance of the line, or had reason to suspect it was unbalanced ?<

::My line has been unbalanced for years and I've taken it for psychiatric help. So far, so good: It's off the pills.

:-)
 
RE: Antenna Lessons from the Old Timers  
by K5ML on May 25, 2007 Mail this to a friend!
Well, I guess I'm an Old Timer. This summer I will complete 50 years as a licensed ham.

First, I think Don's article is great. I practice a lot of what he preaches. Living in a CC&R community, I have 3 stealth antennas fed with window line. One is a 410' loop, another is a 125' centerfed long wire and the third is a 105' inverted with three 66' radials. All antennas are at an average height of well under 20 feet. I have each one hooked up to separate, Johnson 250 w. Matchboxes. Using an Icom 756 Pro III and a 30L-1, working the world is no problem whatsoever. I don't have a balun in the feedlines, and I break all the rules about keeping the feedlines isolated. They all just come into the shack through a plastic pipe next to each other. Nevertheless, all three antennas load fine from 80-10 meters. There is no RF in the shack and it isn't because I have a great ground. I live in the Arizona desert.

My point is simply this: Wire antennas, fed with balanced lines through balanced tuners can be a great antenna system for those who don't want to or cannot put up towers and beams. Putting them up and experimenting with them is cheap, easy and a lot of fun.

Two final thoughts come to mind after reading the comments on Don's article:
1. An expert is just a guy who knows all the reasons why you can't do something.
2. As we get older, we can choose to become bitter or better. Some might call that "binary thinking."

73,
Mick, K5ML
 
Antenna Lessons from the Old Timers  
by KG6R on May 25, 2007 Mail this to a friend!
Great article. I do not understand the negative comments. The twinlead is used as a feed line in this antenna because it has significantly lower line loss than coax.

This antenna works well. I use it daily. Another reference is http://www.cebik.com/fdim/fdim9.pdf

73 de KG6R formerly KG6QHP,

Jim
 
RE: Antenna Lessons from the Old Timers  
by K5ML on May 25, 2007 Mail this to a friend!
Typo in my post above: The third antenna is a 105' inverted L with three '66' radials.
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
K5ML,

Thanks ! Sharing your practical experience is great.

Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
WB2WIK,

Hmmm, reminds me of an article about care and feeding of your transmission lines. Maybe if the line feels better about itself, self esteem and all, the losses will be lower.

Also, I was kidding about using my 2 fingers to look for imbalance and hot spots. I make my wife do it.

Ron
KB8ELK
 
Antenna Lessons from the Old Timers  
by N0AH on May 25, 2007 Mail this to a friend!
The negative responses seem to be that this is a lot of work for an antenna design that will give average performance compared to other antennas in the same space, restrictions, etc......

I can design a car to go top speed at 20MPH fueled by lawn clippings but what's the big deal compared to an average car. And spare me the oil crises comments for at least this century....
 
RE: Antenna Lessons from the Old Timers  
by KB8ELK on May 25, 2007 Mail this to a friend!
I guess different strokes and all, but my interest is (this time around) for one antenna, mainly for 80 and 40 meters, because more than one number left of the decimal point gives me vertigo. I enjoy long winded rag chews, hours on end. NVIS is good for me because that's where the people are I enjoy talking to.

300 to 400 feet of feedline depresses me, I want to minimize losses and cost. Cables that start with LDF and LMR need not apply here (not hiring).

Given those goals, a 135 foot doublet at tree height and parallel feedline seems like a good idea to me. Or a fan dipole and the same parallel feedline. Or a loop.

Perhaps not for everyone, but what if it works and Im real loud ?

Ron
KB8ELK
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 25, 2007 Mail this to a friend!
I forget who said this...
" To cut to the chase, when talking about antenna systems, we call them “resonant” when the capacitive reactance present in the system is equal to the inductive reactance, and the two cancel each other out, leaving the impedance at the load point at its design value—typically 50 ohms. In that magic alignment by the gods of RF, the antenna is able to radiate into space most of the radio frequency energy that is sent to it from the transmitter via a feed line. "

What he is saying is somewhat true, but when I speak of resonant, I am talking about the length of the antenna being some equal multiple of 1/2wave of the frequency it is radiating. Yes, the I-reactance & the C-Reactance equal and cancel, but there is much more going on here. When the antenna is NOT resonant, there is a reflected wave, known as SWR. If this is high enough the I-reactance goes off scale and this reflected energy turns to HEAT! This is why antenna components are rated for the amount of power they can handle,l and what burnes up these components. When the antenna is resonant, the MAXIMUM amount of energy
is transfered from the antenna into space. I don't care what book says what, or how it is presented, this is a FACT of physics! Now is it enough to make a difference, Who knows? However the MAXIMUM amount of energy is transfered at resonance! Shortened antennas can be made to look longer by adding inductance (load coil), at the ANTENNA, but the effect is still the same, the antenna length looks resonant. Effecien0cy is lost to the capture ratio of the antenna, but electrically it still looks resonant!

When you use an antenna tuner in your shack, if your antenna is NOT resonant, it will continue to be non-resonant, but the entire antenna system will look to be resonant at the BACK of your transmitter, and NOT at the antenna!! Again, is it enough loss to affect you? Could be if it is way off. Usually a 135' wire will work out to have multi-wave lengths of 80-10 meters, BUT again...it is NOT-RESONANT on all of these frequencies, but close enough to do a fair job.

Think of it this way, a BELL rings at its RESONANT frequency. A tank circuit is like a bell, and the antenna is also like a bell. Just like the bell, it is the loudest on its resonant frequency!!

73 de W4LGH - Alan
http://www.w4lgh.com
 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
"If someone put on their resume that they have ladder line (required) antennas I would not hire them."

Why not? Is there absolutely *no* imaginable scenario where a ladder-line-fed antenna could be a better overall solution than a coax-fed antenna?

73 de Jim, N2EY

-----------------------

Yes. That is correct. There is no imaginable scenario where a ladder-line antenna is a better overall solution than a coax fed antenna.

And SDR is better at waveforms than spark.

See? sometimes definitives are easy.

But let's chalk it up as a difference of opinion for the moment: You guys STILL HAVE NOT CONVEYED THE MESSAGE that ladder line has inherent safety dangers that coax systems almost always avoid.

GET THE NEWBIES the message.

OK?

73,
Chip W1YW

 
Antenna Lessons from the Old Timers  
by W1YW on May 25, 2007 Mail this to a friend!
I think it is really amazing that 20 years ago, or 30 years ago, you almost never saw articles on 'glow bugs' and 'ladder line' or 'AM'. They were obscure niches that didn't represent the objective of Part 97, which, by definition is a forward-looking service.

Now, instead of interesting little pieces on software defined radio; new modes; new ways of getting your radio to work better; we see articles that really showcase the antiquation of a different era.

What's next guys...galena crystals?

I have a theory about this. My theory is that the vast majority of newbies are CB'ers, who, for most intents, are basically of the CB culture, and have not acculturated. Such folks are, apparently, fairly technology-adverse. As such, things that revert to earlier eras in ham radio appeal to them. And they flock to it.

Is that OK? It depends on what you see ham radio as being. For decades, hams were successful at acculturating newbies into the ham world, without appealing to some distorted niches that neither represent the intent of Part 97, nor the majority of ham activity.

Now, we see exactly the opposite: we see the ham culture morphing to a modified CB culture, with a weird emphasis on old stuff. We see weird things like 'strange antenna' special events where hams make antennas out of lawn furniture and trampolines. Some hams mind you--not all.

Ladder line was the only method of feeding HF/MF antennas for a very long time. But we got past it--50 years ago-- and coax is cheap, plentiful,and practical.

Does ladder line have a niche? That's like asking if a Harvey Wells T-150 has a niche. Sure, it functions, but has inherent limitations that can hardly claim to be 'advancing the radio art'.

Do you LEARN annything from ladder line discussions? I imagine you could, but I haven't seen it here.

Ladder line is a technology that had it's day and dried up. If you want to take some pride in saying it has morphed to microstrip-like feed systems at microwave, that's fine. But really, it's dead.

Sorry to remind you of the corps.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 25, 2007 Mail this to a friend!
W1YW: "I think it is really amazing that 20 years ago, or 30 years ago, you almost never saw articles on 'glow bugs' and 'ladder line' or 'AM'. They were obscure niches that didn't represent the objective of Part 97, which, by definition is a forward-looking service."

"Now, instead of interesting little pieces on software defined radio; new modes; new ways of getting your radio to work better; we see articles that really showcase the antiquation of a different era."

Well, I could make a case for 600 Ohm open-wire line...provided hams can run 15 to 40 KW RF output. That's the way it was done when I first operated on HF back in 1954. It helps greatly to have a square mile of flat island next to a salt-water bay...not to mention about 100 guys with power equipment to dig and raise all the 30- to 50-foot telephone poles that supported all them. :-)

On the other hand, the discone antenna was first described in the early 1950s and I just put one up for 2m and the Scanner receiver. :-)

Yes, I generally agree with you and you have a very good point on the regressive thinking going on in literature and nostalgia-oriented places on the Internet. Once upon a time I thought an R-388 (a Collins 51J-3 with a military nameplate) was the best thing since sliced bread for true comfort in tuning in a signal anywhere on HF. Then I had to calibrate R-391s (R-390 with Autotune added) at work for a special project. Those kept my muscles toned up is about all. What was ONCE "new and exciting" can't always remain that way, but constant reference to "early days" is easy to write about and nostalgia buffs can relive their long-ago youth. <shrug> Thanks, but I will keep my everything-in-one IC-746Pro for a while.

BTW, modeling one of those off-center-fed antennas will show some very strange radiation patterns in some unexpected directions. It isn't the implied panacea for "all bands."

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 25, 2007 Mail this to a friend!
I previously wrote:

"Is there absolutely *no* imaginable scenario where a ladder-line-fed antenna could be a better overall solution than a coax-fed antenna?"

W1YW replied:

"Yes. That is correct. There is no imaginable scenario where a ladder-line antenna is a better overall solution than a coax fed antenna."

What about the scenario I described in the previous post with the house in the center of a lot with trees around the periphery?

What coax-fed antenna would be a better overall solution in that scenario than a simple dipole fed with ladder line and a good balanced tuner?

If you cannot come up with a coax-fed antenna that is a better solution, then your claim has been disproved.

"And SDR is better at waveforms than spark."

Agreed. Hams stopped using spark before 1927 - more than 80 years ago. They stopped using spark because the demonstrated advantages of other methods were so clear and obvious that spark was simply abandoned.

"See? sometimes definitives are easy."

Sometimes, definitives are also wrong.

"But let's chalk it up as a difference of opinion for the moment: You guys STILL HAVE NOT CONVEYED THE MESSAGE that ladder line has inherent safety dangers that coax systems almost always avoid."

Who are "you guys"? I'm just one guy. I say ladder line is just one tool in the antenna toolbox. There are scenarios where it is to be preferred over coax - and other scenarios where coax is to be preferred.

The "inherent safety dangers" of ladder-line are not really any different than those of a simple dipole or inverted-V antenna - high voltage at certain points. They are easily avoided by simple common sense and good engineering practice.

"GET THE NEWBIES the message. OK?"

I just did. Here it is again:

Ladder line can have high voltage at certain points, same as a dipole antenna, and the same precautions taken.

But the main issue I addressed, and which you are avoiding, is that there *are* scenarios where ladder line is to be preferred over coax, because it is the best overall solution.

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by KC7APQ on May 25, 2007 Mail this to a friend!
I really don't have anything constructive to add. When that's the case on these forums it seems I should have something negative or harassing to say but I decided not to do that either.

Jim
N7KFD
 
RE: Antenna Lessons from the Old Timers  
by K5ML on May 25, 2007 Mail this to a friend!
A timeless but wise saying:

This way is my way.
Which way is your way?
THE way doesn't exist.

73,
Mick, K5ML
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 25, 2007 Mail this to a friend!
W1YW replied:

"Yes. That is correct. There is no imaginable scenario where a ladder-line antenna is a better overall solution than a coax fed antenna."


Ok Chip or shall i say Dr.Chip.Phd What makes Coax such a preffered feed line of choice.

And what is the advantages of coax over ladder line?

And what is the disadvantages of ladder line over coax?

Being you are so smart in this area. Please tell me and the many readers of this forum.
So we shall all benefit from your wisdom.
 
RE: Antenna Lessons from the Old Timers  
by W7COM on May 25, 2007 Mail this to a friend!
And Chip: While I may be new to Amateur HF, I did cut my teeth in AM broadcast. Let's see if I remember the formula: 5kV * 1A / cow field @ .98MHz = 1 medium market C&W station.
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 25, 2007 Mail this to a friend!
N3JBH says..."And what is the advantages of coax over ladder line? And what is the disadvantages of ladder line over coax?"

Aren't these 2 questions the same? A little redundant?

Coax over ladder line...hmmmmm... its already 50ohms and doesn't need a matching device to connect to the radio. Being sheilded, coax can run along side any metal object without changing its impedance Coax can be directly burried underground. Some of the newer coaxes with a resonant antenna have very low loss, approaching that of balanced line. Coax is easier to run thru walls, and requires a much smaller hole to enter the shack. You have a much less chance of having a hot-spot on coax. Coax is less affected by adverse weather, such as ice and snow. Coax is certainly a better choice for mobile operation! Coax can handle higher frequencies much better.

Is this enough for now?

73 de W4LGH - Alan


 
RE: Antenna Lessons from the Old Timers  
by N9TA on May 25, 2007 Mail this to a friend!
To W1YW....If we asked you real politely....would you just stop BREATHING....Please???
 
RE: Antenna Lessons from the Old Timers  
by N9TA on May 25, 2007 Mail this to a friend!
Re previous message....strike "Breathing" and insert "typing". Asking him to stop Breathing was a bit harsh....for which I appologize.
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 25, 2007 Mail this to a friend!
N2EY [previously]: "Is there absolutely *no* imaginable scenario where a
ladder-line-fed antenna could be a better overall solution than a coax-fed
antenna?"

W1YW: "Yes. That is correct. There is no imaginable scenario where a
ladder-line antenna is a better overall solution than a coax fed antenna."

"What about the scenario I described in the previous post with the house
in the center of a lot with trees around the periphery?"

"What coax-fed antenna would be a better overall solution in that scenario
than a simple dipole fed with ladder line and a good balanced tuner?"

First of all, a vertical antenna is easier to install and has the fewest parts.

If the dipole (with at least two support masts at the ends) is the desired
one, then a wideband balun at dipole center and coaxial cable feedline
from that insures a number of things:

1. Less wind-loading during storms.
2. Coaxial cable jacket protects the interior from corrossion while ladder
line is continuously exposed, can accumulate dirt which could act to
arc-over during water from rains.
3. Coaxial cable has a more uniform impedance in the event of physical
malformation. Conventional open ladder line can easily change its
characteristic impedance, usually due to twisting.
4. Several companies make combination center-insulator and balun
available as one unit.
5. Lightning/static-discharge devices are simpler with coaxial cable than
with ladder-line; the outer conductor of coaxial cable can be made to
earth ground, not possible with ladder-line.
6. Coaxial cable at the ground end can be buried or elevated without
changing its characteristic impedance or other characteristics.
7. Coaxial cable can pass through outside building walls to the interior
through a single pass-through aperture without any change in
characteristic impedance; not at all so with wire balanced lines.
8. If one winds up with RF on the outside conductor of coaxial cable, just wind the coax over a large diameter former to make an RF choke; the change to the characteristic impedance of the coaxial cable from such winding is minimal, on the order of 2%. That can't be done with balanced open-wire line.

In fairness, balanced 450 Ohm line weighs slightly less than small
(RG-8X) coaxial cable but, in reality, few amateur radio dipoles are up
higher than a half wavelength below the 20m band. The amount of
extra tension on the end support masts from using coaxial cable
feed from the middle rather than open-wire lines can be calculated
from simple mechanical engineering equations, is not excessive.

"If you cannot come up with a coax-fed antenna that is a better solution,
then your claim has been disproved."

So far you have come up with NOTHING that indicates the superiority of
ladder-line...except that you probably use that at your QTH. :-)

An off-center fed dipole is inherently UNbalanced over most of its frequency
range regardless of what kind of feed is connected to it. Using a "balanced"
ladder-line feed is NOT going to "balance" that condition. The impedance
characteristics aren't going to be close to a dipole. Coaxial cable can stand
considerably more peak voltage than manufacturer's specifications state,
even the smaller outer diameter RG-8X; hi-pot any short section of coax to
see for yourself. Coaxial cable can easily handle 10:1 SWR at 100 W.

The major reason for using open-wire balanced feedlines with high-power
transmitters was RF current. Those powers are way in excess of what US
radio amateurs are allocated. BTW, open-wire feeds in old days was 600
Ohms, not 450 Ohm as with most ham ladder-line. Nowadays the high-
power RF radio services all use large unbalanced coaxial cable, pressurized
and dried air preferred, sometimes even with nitrogen. The lower-power radio
services use coaxial cable because it is much easier to install and
maintain, has less line loss per unit length than balanced line at higher
characteristic impedance.


"The "inherent safety dangers" of ladder-line are not really any different
than those of a simple dipole or inverted-V antenna - high voltage at
certain points. They are easily avoided by simple common sense and
good engineering practice."

'Easily?!?' Go model the impedance over frequency of a typical off-center
fed dipole (the one that Don Keith used in his article opening). Report back
on the magnitudes of voltage and current over the HF ham bands. Better
yet, tell us WHY a balanced-line feed to an off-center-fed dipole is "better"
than a coaxial feed through an unbal. Use some of your vast experience
with radios at Conrail.


"But the main issue I addressed, and which you are avoiding, is that there
*are* scenarios where ladder line is to be preferred over coax, because it is
the best overall solution."

WHAT are those 'scenarios?' You haven't presented your case yet. Try
to limit these unproven Pronouncements.

73, Len AF6AY
 
Antenna Lessons from the Old Timers  
by KW6H on May 25, 2007 Mail this to a friend!
Thanks for the article.

When first licensed a couple of years ago, I put up a GAP Titan (coax-fed multiband vertical) mostly for the higher bands: I worked a fair amount of DX, but it was useless for our 2-county emergency net on 75 phone (nights), and 40M (days), which really requires NVIS operation. My elmer suggested (and helped me put up) a 130-foot doublet fed with 450-ohm window line, with a transmatch, or antenna tuner, or whatever you want to call it. The dipole is about 30 feet up, optimized for 75M NVIS use and much too low to be optimal for DX use, of course.

Well, guess what? About 1/3rd of the time, that low dipole gives me better DX on 20 through 15 than the Titan does. I guess the lobes at 2 or 3 wavelengths
just happen to line up with where I want to work often enough to make it worth trying both antennas on a high-band DX attempt.

Will I put up a tower and beam for 20M and up when funds permit? Of course! However, in the mean time, that 80M dipole + window line + matcher system lets me have a lot of fun on the bands, including working Australia and China, and as I said, it *sometimes* works better for DX than the Titan does.

73 DE KW6H, Chris
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 25, 2007 Mail this to a friend!
"I think it is really amazing that 20 years ago, or 30 years ago, you almost never saw articles on 'glow bugs' and 'ladder line' or 'AM'. They were obscure niches that didn't represent the objective of Part 97, which, by definition is a forward-looking service. "

Good, finally we come to the crux of the matter. You imagine that ham radio is turning into a weird nostalgic reenactment activity.

"I have a theory about this. My theory is that the vast majority of newbies are CB'ers, who, for most intents, are basically of the CB culture, and have not acculturated."

Chip, you're the one who hasn't acculturated. Not everyone in ham radio is rapidly advancing the radio art by making significant contributions to the technology. It's likely not been since the days of spark that each and every ham was rapidly advancing the radio art, and then it was just lucky accident that there was no radio art, so everything new was a great leap forward.

The 1942 issue of QST that the ARRL has been sending out free with publication purchases has the announcement suspending radio operations for the duration of wartime... In it there is how hams may get back on the air for legitmate defense-related communications, and a careful admonishment that applying to get back on the air for rag-chewing will not be tolerated. This, of course, was a matter of emergency, but it shows that there were a bunch of people who just wanted to get on and talk in 1942, and yet, the FCC saw fit to reactivate ham radio after the war and let it keep going at least till the present.

If the FCC were to interpret its own rules the way you seem to, ham radio would have ben shut down long ago: waste of spectrum, all that.

Ham radio is still sufficiently valuable to the FCC to continue administering it. That suggests to me that we're not collectively far off base with regard to Part 97.

Dan
 
Antenna Lessons from the Old Timers  
by MACKAY3031A on May 25, 2007 Mail this to a friend!
open wire line is wonderful,except no sharp turns are allowed and icing can be a penalty.I would use it but my xyl does not for some reason like antennas for their obvious to me aesthetic appeal.Coax can be buried to the antenna,something open wire line cannot easily do!The longwire, made of magnetwire for stealth can run to a window and be worked against a good ground for excellent effect.Not for the qro type however!(RF IN THE SHACK)I wonder why the dipole is so exalted when you can get actual gain from a mere piece of wire?Probably space requirements.....Even so if you can use it, open wire line is excellent for hf.KI4WCA
 
Antenna Lessons from the Old Timers  
by KG6R on May 25, 2007 Mail this to a friend!
Chip,

OM this is a multi band dipole doublet.

You said:

<<W1YW: "Yes. That is correct. There is no imaginable scenario where a ladder-line antenna is a better overall solution than a coax fed antenna." >>

Well the antenna in this article has a scenario where feeding with ladder line is far superior to coax.

In the following article by Cebik at

http://www.cebik.com/wire/abd.html

Under heading 4 he notes that on 10 meters, this antenna fed with 100 feet of rg8x coax would result in a loss of 10.8 db

If you used 450 ohm ladder line, the loss is a mere .4 db.

In the Cebik article, the table notes that on every band 80-10 the line loss is much less with ladder line than coax.

This antenna may be too simple and effective for experts. Remember experts built the Titanic, amateurs built Noah's ark.

73 de KG6R,

Jim
 
RE: Antenna Lessons from the Old Timers  
by KC5CQD on May 25, 2007 Mail this to a friend!
"Don't use ladder line. Ever."

Why not?

73 de Jim, N2EY



Exactly. Why not? I've been using homebrewed open wire feeder for years now and I've had the best results I've ever had with a wire antenna. Although Coax is convenient it blows as a feed line. Open wire feeder takes more effort but it's far superior to "mini 8".
 
RE: Antenna Lessons from the Old Timers  
by W4EF on May 25, 2007 Mail this to a friend!
For a 1000 foot run at 14 MHz, matched 450 ohm ladder line would result in ~1dB of loss. To get that same loss in a 1000' run of coax, you would need 7/8" heliax (allowing a few tenths of a dB for the 9:1 transformers needed for the ladder line antenna). Coax might be more unforgiving in terms of installation requirements since you could just lay it on the ground, whereas you would need the ladder line suspended from something to keep it off the ground (and twisted occasionally to minimize radiation). This would tend to reduce the roughly 10:1 cost disparity between heliax and ladder line (i.e. ladder line might be more expensive to install than its Heliax counterpart if lots of poles had to be set to hold up the ladder line compared to just laying heliax on the ground).

BTW, this tradeoff has nothing to do with technological state of practice as was suggested by another poster. This tradeoff is simply driven by the inherent physics of a high impedance line versus a low impedance line.

73, Mike W4EF.....................
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 26, 2007 Mail this to a friend!
"This antenna may be too simple and effective for experts."

Not for *real* experts! A real expert looks at all the pertinent factors.

"Remember experts built the Titanic, amateurs built Noah's ark."

I always saw that written as "*Professionals* built Titanic...."

However, note this:

It wasn't Titanic's construction that was the problem (though brittle steel in the hull probably made a difference). The big problem was how the ship was *operated*.

Titanic's sister ship Olympic served so well for 25 years in the transatlantic routes that the ship was nicknamed "Old Reliable". Olympic served as a troopship during WW1, and at one point not only evaded a German torpedo attack, but then chased, rammed and sank the attacking U-boat.

Most of all remember who the designers were.....

73 de Jim, N2EY

 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 26, 2007 Mail this to a friend!
"Is there absolutely *no* imaginable scenario where a ladder-line-fed antenna could be a better overall solution than a coax-fed antenna?"

Here's an antenna scenario:

A radio amateur's residence consists of a lot that's 150 feet square, with the house near the center of the lot and a few trees near the border. The trees are mature maples and oaks. It would be a simple matter to use lines in two of the trees to hold a center fed dipole of up to 140 feet in length. Such a dipole would be about 50 feet in the air, with the feedline hanging straight down.

The feedline could be routed vertically along the back wall of the house to a basement window and into the basement hamshack.

The house is only 25 feet high at the highest point, and other than the previoulsy mentioned trees and the house itself there are no useful existing antenna supports.

There's a driveway, a deck, gardens and walkways and a shed, so installing an extensive radial system isn't practical.

The radio amateur wants an effective HF antenna system that will work on any amateur frequency from 3.5 to 29.7 MHz and present an SWR under 1.5 to 1 at 50 ohms.
The antenna system needs to provide good radiation above 30 degrees takeoff angle on the bands below 10 MHz, for local/regional QSOs, and good radiation below 30 degrees takeoff angle on the bands above 10 MHz, for DX. (The amateur likes to ragchew, contest and work DX, using a variety of rigs and modes).

The amateur has an SWR indicator and can build a good balanced or unbalanced manual tuner.

The amateur's antenna budget, in both time and money, is rather limited. A tower/beam/rotator setup is out of the question, and would not cover all the required bands anyway.

While there are no CC&Rs, the antenna system should be as inconspicuous as possible.

I say that the best choice for this scenario is a simple single-wire, center fed dipole with ladder-line feed and a good *balanced* tuner> With judicious choice of dipole and feedline lengths, such an antenna system would be capable of excellent results *and* 1:1 SWR to the rigs on all ham bands 80 through 10, and probably 160 as well. It would also be good on MARS frequencies and for SWLing.

It could be quite inexpensive if the tuner, antenna and feedline were homebrewed.

No tower, no masts, no guy wires, no extensive radial system, not very visible if the ladder line is made with some thought, no building permits, no variances, no climbing, very little maintenance. Done right, the neighbors wouldn't even know it was there unless it was pointed out.

btw, this isn't a one-of-a-kind residence. There are lots of them around here.

What coax-fed antenna of comparable performance, price and simplicity could be installed at that QTH which would have all those features and meet all the requirements, including cost?

I say the ladder-line-fed-dipole system I just described is a better overall solution for the scenario than any coax-fed antenna.

Can the experts prove me wrong by describing a better solution?

I think not.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 26, 2007 Mail this to a friend!
And if you put up two G5RVs at about 30 degrees apart you can often direct a main lobe where you want it. Anybody noticed the gain in the main lobe of a G5RV on 10 meters?
Buffalo Gil W2/G3LBS
 
Antenna Lessons from the Old Timers  
by N4VNZ on May 26, 2007 Mail this to a friend!
Jeez Louise! Put up what you want and operate...

I'm getting a headache...

Goodbye
 
RE: Antenna Lessons from the Old Timers  
by K7LRB on May 26, 2007 Mail this to a friend!
Right on N4VNZ, the best advice so far!

Just observe good safety practices.

Gee, the bands sure are quiet. Where IS everybody? Oh yeah, here on "ham radio". HAWRF!

73,
de Larry
 
RE: Antenna Lessons from the Old Timers  
by W0IVJ on May 26, 2007 Mail this to a friend!
W1YW said:

"There is no imaginable scenario where a ladder-line antenna is a better overall solution than a coax fed antenna."

For field day we are contemplating an extended double zepp for 40 meters. At 65 feet above normal ground the feed point impedance is 127 - J694 and the gain over a dipole at that height is 3 db. If you feed the zepp with 100 feet of RG-11 (RG-8 does worse), and drive it with 100 watts, you get 28 watts to the antenna. If you feed the zepp with 100 feet of 450 ohm ladder line and into an antenna tuner, you get 77 watts to the antenna even if you use 10 feet of ferrite bead loaded coax to keep the high voltage contained. That is a 1 db drop from the almost 100 watts that you can get into the dipole. Subtracting the 1 db loss you get from the feed system of the zepp from the gain of the zepp over the dipole gives a difference of 2 db. The net gain of the zepp over the dipole is 2 db only if you use the 450 ohm ladder line. If you leave the coax out and feed directly into a balanced antenna tuner, the gain is more like 2.5 db. I don't think nearly half the power is insignificant even if it is only 1/2 an S-unit. If the antenna is further away than 100 feet, the difference is even more pronounced. You just cannot make blanket statements. Engineering is taking the particular situation, running the numbers, and deciding on the best compromise.

73 Tom W0IVJ
 
Antenna Lessons from the Old Timers  
by KI9A on May 26, 2007 Mail this to a friend!
Wonderful article! Nice job!

73-Chuck KI9A
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 26, 2007 Mail this to a friend!
"extended double zepp for 40 meters. At 65 feet above normal ground the feed point impedance is 127 - J694 and the gain over a dipole at that height is 3 db. If you feed the zepp with 100 feet of RG-11 (RG-8 does worse), and drive it with 100 watts, you get 28 watts to the antenna. If you feed the zepp with 100 feet of 450 ohm ladder line and into an antenna tuner, you get 77 watts to the antenna even if you use 10 feet of ferrite bead loaded coax to keep the high voltage contained. That is a 1 db drop from the almost 100 watts that you can get into the dipole. Subtracting the 1 db loss you get from the feed system of the zepp from the gain of the zepp over the dipole gives a difference of 2 db. The net gain of the zepp over the dipole is 2 db only if you use the 450 ohm ladder line. If you leave the coax out and feed directly into a balanced antenna tuner, the gain is more like 2.5 db."

And if you intend to use the antenna for 40 meters only, you may be able to eliminate the tuner. Particularly if you are going to use the antenna for only one mode.

Here's the trick:

If you pick the right combination of transmission-line impedance and length, the line can transform the 127-j694 feedpoint Z to 50 ohms resistive. For example, 0.85 wavelengths of 525 ohm line will get you close to 50 ohms at the shack-end of the line with no tuner at all. Then all you need is a 1:1 balun and you're set to go.

Of course 525 ohm line isn't standard - you'd have to make it. 0.85 wavelengths of ladder line at 40 meters is around 110 feet, so if the antenna is up 65 feet and the shack isn't directly under the wire, it works out pretty well.

Of course you may want to use a tuner anyway, particularly if you want the antenna to cover the whole band. You may not want to build custom ladder line.

But if Z of the shack-end of the feedline is already close to 50 ohms, the tuner can be very simple and lowloss.

"Engineering is taking the particular situation, running the numbers, and deciding on the best compromise."

I would add "considering all the factors" in there, too.

---

In any event, you have demonstrated another scenario where ladder line does a better job than coax, simply by applying sound engineering methods.

But I don't think it's really about engineering for some folks. To them, it's really all about new vs. old, in which "new" is always better than "old".

But to me, neither old nor new is a reason to accept or reject something. It should be judged on the merits.

73 de Jim, N2EY





 
Antenna Lessons from the Old Timers  
by KB6VDO on May 26, 2007 Mail this to a friend!
Don Keith, N4KC, really hit the highlights of ham radio for a ham on a limited budget with limited space or any ham for that matter. Some response comments, above, completely missed his point. Don's advice is very good and to the point.

A few years ago, when I was yet a "resonance" band only freak, as the younger folks say, we traveled to Bend Oregon from Santa Clara California, in our old motor home. I had made a telescoping ~ 40 tall vertical antenna, for our motor home, which could easily be popped up and used on most bands, 75/80m, 40m, 20m, and 17m for certain. It is fed by 50 ohm coax and uses an automatic transmission line tuner to match. A top loading Hustler coil makes it a match for the 75m phone band. This works well simply because of the short length of coax from the ATU to the antenna's base is fairly low loss. However, you can see that this was already leading me to Don Keith's antenna loading methodology.

Well during this trip I hooked up, on forty meters, with Ed Smith, W6WRL, who was my boss sixty years ago when we both worked at Dalmo Victor in San Carlos, CA. We were chatting when a ham, whose name and call I, unfortunately, I have forgotten broke in and talked with us. This old timer was located in Marin county, CA.

This Marin ham told us that when he first moved to his present location he put up a very expensive tower with beams driven by coax feed lines, and started working DX. One day for some reason, unknown to me, he decided to put up a long "doublet" antenna, resonant on 160M so that he could work all the ham HF bands above and including 160m. He claimed that he has not, regularly, used his beam/s again because he can make more DX contacts using this super doublet antenna than he can using his beam/s. He was using his doublet on forty meters, that day, and was very good into Dunsmuir CA at the RV park where we were staying. Ed, W6WRL, who had a similar antenna was also very strong into my mobile station. Of course, Ed agreed with this Marin county resident.

The upshot of the above was, when we arrived at home, up went my long doublet, it was not long enough to hit the top band, 160m, but it was long enough to resonate on 80m, fed with ladder line to a home made trifilar choke balun and a Nye Viking 3KW transmission line tuner (I never run power). (My home brew balun is better than Nye Viking's because it has 12ga wire and a high quality ferrite core; its measured loss is less than 0.1 db (another story) It is good on any ham HF frequency.).

I get extremely good signal reports on any band I work 80m through 10m.

So all you resonance freaks out there with your short dipoles, take notice, what Don Keith has told you applies to all kinds of antennae: loops; dipoles; long wire; off-center fed; delta loops; and on and on. Pick one out that will hit the lowest band you wish to work and use ladder feed line to a quality balun and your transmission line match unit. Unfortunately commercial baluns, in my experience, are not very good. Note, the ARRL has some good books on making your own balun; a good investment. The one on Transmission Line Transformers is excellent.

In short, for those of you who do not, yet, understand what Don Keith, N4KC, is telling you, any antenna you have made work well on one band with coax feed line should this coax be changed to ladder/window line balun and transmission line match unit, then it will work very well on most if not all the HF ham bands above its resonance band.

Thank you Don for an excellent article.

Best of 73s, de kb6vdo, Jim
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 27, 2007 Mail this to a friend!
Ladder line does work, and is very low loss, but one must remember that it is affected by all weather conditions, wind, rain, ice and show. Long runs get complicated because of support issues and if not supported properly it will break very easy. It is also more obvious to your neighboors, as it is almost impossible to hide it! Also the use of a tuner is very lossy, and usually what you gain in the low loss
ladder line is more than made up with the loss in the tuner! a GOOD 9913 or LMR400 coax only has about .5db of loss (per 100') in the HF bands. Even the best antenna tuners made have that or more loss. Coax can be burried, lay on the ground, hiden very easy, taped directly to metal structures and supported very easy.

Now you know both sides, make your own choice!

73 de W4LGH - Alan
http://www.w4lgh.com
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on May 27, 2007 Mail this to a friend!

"The net gain of the zepp over the dipole is 2 db only if you use the 450 ohm ladder line. If you leave the coax out and feed directly into a balanced antenna tuner, the gain is more like 2.5 db."


Similar to what N2EY suggested but easier:

You can easily feed an EDZ with 50 ohm coax via a 0.144 wavelength section of 450 ohm ladder line and a 1:1 current balun. Accounting for velocity factor of the ladder line, the matching section is 19.25 feet long for 7.0 Mhz. Make it about a foot longer and trim it for best SWR (much easier to trim than add line).

Fed the rest of the way with 9913 coax, or 100'-19.25' = 80.75', the loss in the coaxial line at 7 Mhz is only about 0.36dB, and the loss in the ladder line is so low it isn't worth calculating.

I've used this method of feeding an EDZ on 15 meters and it works excellent.


...WA1RNE
 
RE: Antenna Lessons from the Old Timers  
by N4KC on May 27, 2007 Mail this to a friend!
Surely you must know that W1YW and others feel the need to stir the pot by taking a contrarian stance on many of the posts on these forums. Those guys serve a useful purpose, of course. If everyone agreed with everybody, this would be a rather dull exercise. And as bright and knowledgeable folks, they have the opportunity to help us all better understand a complicated subject while we benefit from their expertise and their willingness to share it.

Unfortunately, they often come across as condescending at best and as downright arrogant and rude blowhards at worst. That's too bad.

My hope is that articles like mine will make a few newcomers curious about how antennas work. Then, maybe they’ll get out and string up some wire and make some contacts and have some fun while they learn and apply that new knowledge. Or maybe a young one or two will be bitten by the bug and go on to discover the next great breakthrough in RF transducers or a competing technology to fractal antennas.

A center-fed dipole, fed with ladder line, is a simple, cheap and very effective multi-band antenna. Most anyone can build and experiment with it and have good results with it, even if it is antiquated technology. It works just as well today as it did in 1935, which is still better than most other simple, cheap and effective alternatives. I hear so many new hams trying to work with a Hamstick on a broom handle in the backyard or a twenty-foot-long piece of wire, using a tuner, when, with just a little effort and guidance, they could greatly enhance the experience. I can’t imagine that their initial impressions of our wonderful hobby will be that positive, and especially if we old-timers tell them how stupid they are for not already knowing everything there is to know. None of us was born knowing this stuff. Few of us are engineers. It's been a while since I cracked a trig book and I still go cross-eyed looking at a Smith Chart.

I think it’s we gray-hairs who should politely and positively stoke the fire in those who have an interest. If they choose to let the spark die out, then fine. At least we tried!

73,

Don N4KC
www.n4kc.com
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 27, 2007 Mail this to a friend!
I think one of the most important things for hams reading these articles and the ensuing personal and technical wars to learn is that the sum total of all the antenna knowledge and information in the world is absolutely useless to you if you don't try *something*. It doesn't matter what some guy on eHam says about a particular antenna system if you never try anything. It doesn't matter if someone's channeling Maxwell's ghost or is Walt Maxwell...

It's good to learn how to tell the factual comments from the emotional ones on an internet forum so that you don't get led astray, but the easiest way to do this is to learn all this stuff by reading about it and building some antennas.

Be scientific about your comparisons, not emotional. Put two antennas up at the same time and compare them.

This is the most straightforward way to make antenna improvements in your shack... the A/B comparison, averaged over a long time of your operating habits.

The weak antennas will die and the strong will thrive when they compete against each other. An open wire fed doublet is a good antenna to pit other antennas against if you can't have a ton of antennas. Find your favorite band, and try another antenna for it. If it doesn't beat your doublet, kill it. If it does, trust me, you'll figure out a way to keep it up and working for you.

73,
Dan






 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 27, 2007 Mail this to a friend!
By the way Don,

I liked your original article a lot. Didn't mean to spend the whole time sparring with Chip without commenting on its worth.

73,
Dan
 
Antenna Lessons from the Old Timers  
by KD6HUC on May 27, 2007 Mail this to a friend!
Can I just say this article has been a breath of fresh air? It seems many who cast doubt may very well have purchased stock in companies who sell the so-called multiband reduced size antennas. I have only been licensed since 1992, but agree 100% with most of this article. Perhaps if I had a few hundred acres free then I would have multiple resonant antennas for each band I use mounted at different heights and configurations to provide best possible communications to any location I need to work. Hey does anybody have a free Steppir Big Vertical I can have?

Branden
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 27, 2007 Mail this to a friend!
"It seems many who cast doubt may very well have purchased stock in companies who sell the so-called multiband reduced size antennas"

Some of them started such companies ;-)

Dan
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 27, 2007 Mail this to a friend!
N4KC: "Surely you must know that W1YW and others feel the need to stir the pot by taking a contrarian stance on many of the posts on these forums. Those guys serve a useful purpose, of course. If everyone agreed with everybody, this would be a rather dull exercise. And as bright and knowledgeable folks, they have the opportunity to help us all better understand a complicated subject while we benefit from their expertise and their willingness to share it."

"Unfortunately, they often come across as condescending at best and as downright arrogant and rude blowhards at worst. That's too bad."

Ahem...sometimes the article starter does...:-) [Surely, I jest] [and I promise never again to call you 'Surely']

"My hope is that articles like mine will make a few newcomers curious about how antennas work."

First lesson: ANY piece of wire will radiate RF if fed properly.

"Then, maybe they’ll get out and string up some wire and make some contacts and have some fun while they learn and apply that new knowledge."

A couple of (unwritten) provisos: There's space available and trees or other available high structures are available. Not always the case, especially with young newcomers.

"Or maybe a young one or two will be bitten by the bug and go on to discover the next great breakthrough in RF transducers or a competing technology to fractal antennas."

Not if all they read are Tom Swift tales or books on HF wire antennas of the old days (available, shipping extra from youknowwho).

"A center-fed dipole, fed with ladder line, is a simple, cheap and very effective multi-band antenna."

An off-center-feed (a la G5RV) WITH an antenna tuner is favored by most. 'Effective' is subjective. An antenna with two arms is going to have a very blobby horizontal and vertical pattern plus a remarkably wide-ranging feed impedance when fed at a frequency off its 'resonance.' An antenna tuning (matching) unit is almost mandatory to maximise power transfer but you can't do much about the blobby patterns.

Let's face it...e-ham seems to be HF-centric. The upper limit of ham radio is NOT 29.7 MHz.

"Most anyone can build and experiment with it and have good results with it, even if it is antiquated technology."

The discone I have up now was invented a half century ago. Excellent VSWR from 0.1 to 1.0 GHz, requiring no matching to 50 Ohms, omnidirectional horizontal pattern. A vertical antenna has only one thing sticking up (itself) and doesn't need supports for the ends or the feed point (for very long HF dipoles). Omnidirectional pattern with enough buried radials, not the blobs of 'off-resonance' dipoles.

"It works just as well today as it did in 1935, which is still better than most other simple, cheap and effective alternatives."

ANY piece of wire or conductor will radiate RF if fed properly. The US military backpack HF transceiver, AN/PRC-104, operates on the entire HF band with only a long whip antenna. Almost a quarter-century old operationally, it incorporates an automatic antenna tuner (to the right of the main box looking at the front panel) in order to maximize getting its 20 W PEP into that whip. The operator and metal case is its counterpoise.

450 Ohm ladder line, purchased new, is half the cost of new coaxial cable. Ladder line is made the same way as old 300 Ohm TV twinlead plus the punching-out of squares in the plastic webbing separating the two wires. If one can still get it, 300 Ohm twinlead is even cheaper and will work. Or, if some more dollars are available, a combination center insulator-separator with built-in balun for coax output can be obtained. That would greatly lessen any RF pickup or radiation from balanced line and withstand harsh elements a lot better than ladder line. If ladder line doesn't end at the drop bottom, then it needs supports along its horizaontal path...more cost, more work; coax can be buried or, if not buried, is less obtrusive than ladder line. Lighting/static-build-up-suppression is a lot easier with coax than any balanced line.

"I hear so many new hams trying to work with a Hamstick on a broom handle in the backyard or a twenty-foot-long piece of wire, using a tuner, when, with just a little effort and guidance, they could greatly enhance the experience."

'Enhance?' How? Is the purpose of amateur radio to communicate by radio or is it to spend time constructing wire antennas and tuning them up? The only thing physical labor does is to teach the laborer how physical the work is. The only thing "learned" about wire antenna installation is supporting them somehow, finding out how some supports just don't work (when they come unraveled) and some odd carpentry and metal-working skills. Theory? Nada, nyet, nothing while putting them up. Nothing at all about the influence of other, nearby conductors on either feed impedance or radiation patterns. How many have antenna analyzers? How many old-timers have one? If they have one, will they let newbies use it?

"I can’t imagine that their initial impressions of our wonderful hobby will be that positive, and especially if we old-timers tell them how stupid they are for not already knowing everything there is to know."

All those old-timers are busy telling other old-timers how stupid they are. Since most of the e-ham article perusers ARE old-timers, not to mention HF-centric, there don't appear to be too many newcomers in here. :-(

"None of us was born knowing this stuff."

True, but some in here sound like they were...:-(

"I think it’s we gray-hairs who should politely and positively stoke the fire in those who have an interest."

Good words but that's isn't looking at US amateur radio AS IT IS. Todays license statistics show 300 thousand Technician licensees, roughly 2/5ths of all US ham licensees. The vast majority of them HAD to begin operating on VHF and above in ham radio. It was the law. Few of them are "into" the 1935-era of wire antennas although some wire antennas will scale down to VHF. Given that the number of newcomers ARE keeping pace with expirations, there's still some 'spark' left for radio among the newbies. But, that 'spark' isn't of the 1935 era of radio. Newbies are INTO newer technologies and aren't afraid of it like so many of the gray hares. Trying to show them old technologic traits may sound good to other old hares but it's like, man, a big thud to younger folk.

Besides, REAL MEN of old used rhombics on four poles for DX...and with 600 Ohm open-wire lines! :-)

73, Len AF6AY [always older than the FCC]
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 27, 2007 Mail this to a friend!
"You can easily feed an EDZ with 50 ohm coax via a 0.144 wavelength section of 450 ohm ladder line and a 1:1 current balun. Accounting for velocity factor of the ladder line, the matching section is 19.25 feet long for 7.0 Mhz. Make it about a foot longer and trim it for best SWR (much easier to trim than add line).

Fed the rest of the way with 9913 coax, or 100'-19.25' = 80.75', the loss in the coaxial line at 7 Mhz is only about 0.36dB, and the loss in the ladder line is so low it isn't worth calculating."

Yep, you can do it that way too. All depends on the circumstances.

Be sure to remember that a transmission line which is a half-wave long electrically will repeat the input impedance at the other end. So you could add a half-wave of ladder line to the above and save some dollars and a fraction of a dB of loss.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 27, 2007 Mail this to a friend!
"Ladder line does work, and is very low loss, but one must remember that it is affected by all weather conditions, wind, rain, ice and show. Long runs get complicated because of support issues and if not supported properly it will break very easy."

Agreed, but those problems can be dealt with.

Most amateur radio antenna work is over 90% mechanical engineering and less than 10% electrical engineering.

"It is also more obvious to your neighboors, as it is almost impossible to hide it!"

I disagree! Properly made ladder line can made very inconspicuous. Particularly compared to, say, half-inch black coax.

"Also the use of a tuner is very lossy, and usually what you gain in the low loss
ladder line is more than made up with the loss in the tuner!"

That's simply not true for all tuners. Tuner loss is affected by many factors, and "very lossy" simply is not the general case.

And a tuner is often used with coax feed anyway, since "modern" rigs require near-unity SWR to work right.

Besides, what really matters is the overall *system* loss.

"a GOOD 9913 or LMR400 coax only has about .5db of loss (per 100') in the HF bands."

The data sheet shows 0.7 dB per 100 feet at 30 MHz. And that's when the cable is brand new and perfectly matched.

And it costs how much?

"Even the best antenna tuners made have that or more loss."

Not necessarily. And as I have demonstrated in other posts, there are applications where no tuner is needed for ladder line.

"Coax can be burried, lay on the ground, hiden very easy, taped directly to metal structures and supported very easy."

Yep, it's very convenient to use. And for a wide variety of applications, it's the transmission line of choice.

But not for *all* amateur uses. That's the point.

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by KN4LF on May 27, 2007 Mail this to a friend!
Excellent antenna article Don. I've been using 300-450 ohm open wire line doublets for 20 years and have always had excellent results. The excellent results include doublets hung low in height (<1/2 wave) and via QRP power level. The one thing that I would add would be to use a balanced link coupled antenna tuner like the Johnson Viking Match Box, instead of a typical tee network antenna tuner with 4:1 BALUN.

For all the newbies I say ignore all the flamers, naysayers and trolls, especially the ones that beat their chests while invoking their education levels. LID city.

73,
Thomas Giella, KN4LF
Lakeland, FL, USA
http://www.kn4lf.com
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 27, 2007 Mail this to a friend!
Yes very good artical, those who don't use ladder line i don't hear everyday, but as they say i can hear you, your 20 over s9,and they are s9 at best, add in a few lightning crashes and there gone, and also to the new guys coming into the hobby, those who brag the most about there education level are exactly that braggers, those who truly truly know don't have to brag... N9FE
 
Antenna Lessons from the Old Timers  
by W1YW on May 27, 2007 Mail this to a friend!
Yep, it's very convenient to use. And for a wide variety of applications, it's the transmission line of choice.

But not for *all* amateur uses. That's the point.

73 de Jim, N2EY

--------------

No; the point is there is no scenario where you HAVE to use it. Not properly alerted?-- it is inherent dangerous.

And the author CONTINUES not to correct the article and WARN ABOUT SAFETY ISSUES inherent to hardline.

Since when is a concern for safety in ham radio a 'contrarian' attitude??

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 27, 2007 Mail this to a friend!
To W1YW....If we asked you real politely....would you just stop BREATHING....Please???

---------------------------------------

SO, you want me dead?

REALLY?

I am sorry to disappoint you, but at 52, with no medical conditions; no 'scrips as medicine; and a compliment as recently as yesterday that I look 38 (from a 38 year old who didn't know my age), I venture to say that I will breath for quite some time thanks; and will make an especial point to do so for the very same that may wish otherwise:-)

Isn't your reaction a bit extreme to defend ladder line?

Get a grip OM.
 
Antenna Lessons from the Old Timers  
by W1YW on May 27, 2007 Mail this to a friend!
By the way Don,

I liked your original article a lot. Didn't mean to spend the whole time sparring with Chip without commenting on its worth.

73,
Dan

------------------

You didn't spar with me; don't elevate yourself beyond your height OM. Or should I say young man?

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 27, 2007 Mail this to a friend!
I said..."Also the use of a tuner is very lossy, and usually what you gain in the low loss
ladder line is more than made up with the loss in the tuner!"
N2ey said...
"That's simply not true for all tuners. Tuner loss is affected by many factors, and "very lossy" simply is not the general case."

You know, I never said "DON'T" use ladder line, I only pointed out the drawbacks to using it. Also I would really like to know if anyone who supports LOW TUNER LOSS as ever put watt meters on both sides of the tuner and compaired the input power to the output power, and actually measured the loss in the tuner? You might be surprised at what you see. The basic design of a tuner is basically the same for just about every tuner out there. Granted a better roller inductor with a higher Q will have a little less loss, but the overall design is pretty much the same. For the price of a really good tuner, one could really buy a nice antenna system. The ARRL did a lot of testing with tuners and printed the results in QST. For what it was worth, I believe they said the BEST tuner they tested had 11% loss and some went as high as 35%!! Also there are a lot of people out there who do NOT truely understand how to tune their tuner properly. Ever seen a burned wafer swich in one, arced air caps? Wonder how that happened? Another thing I have seen done over and over is feed ladder line with a 4:1 balun just outside the shack to make it easier to work with. Well 4:1 on 50 ohm line is only 200ohms into a 450ohm line or higher if the antenna is way off, and that in itself is a major loss! Better than 3db right there. Anytime you feed a high with a low there is a loss. If one really wanted to feed it that way, they would need a 9:1 balun to keep the match the same.

So all is NOT as rosey as some people would make it out to be, and are forgetting a lot of other factors in the overall LOSS in their antenna system.

I know that when 1000watts leaves my shack thru LMR-400 cable, it loses about .5db and shows 891 watts at the antenna. I also know that a cut to resonant freq. 1/2wave dipole, 1/2wave above the ground, will also show about 2.1db of gain in its main lobes or an ERP of 1445.4 watts. Not to shabby, I would say.

And the last question, how much does this LMR-400 cable cost? A lot less than a really nice low loss 1500watt antenna tuner!! $650 compaired to about $65 worth of wire, or a 10th! This leaves a bunch of money left over to build all kinds of antennas!

So...again if ladder line is what you want to use, so be it! Just doesn't work for me! Not cost effective.
======================================================
Notes for reference: the price of the tuner used was the Ten-Tec 238-B 2000watt tuner, which tested the lowest loss tuner on the market, around 11% loss.
======================================================

So lets compair apples to apples. Anyone can change the numbers around, but these were actual measured figures. And @ 11% loss in the tuner at 1000watts is 110watts lost.. or gee... .5db, the same as my $65 cable.

Use whatever works for you. The difference at the far end from 100watts to 1500watts is about 2 s-units, doesn't sound like a lot, but it could make a difference from being heard or not heard. And I want as many of my watts to be radiated into space and not turned into heat! We don't need the heat in Florida!

73 de W4LGH - Alan
http://www.w4lgh.com



 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 27, 2007 Mail this to a friend!
"You didn't spar with me; don't elevate yourself beyond your height OM. Or should I say young man?"

QRU.

Dan
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 27, 2007 Mail this to a friend!
N9FE: "Yes very good artical, those who don't use ladder line i don't hear everyday, but as they say i can hear you, your 20 over s9,and they are s9 at best, add in a few lightning crashes and there gone, and also to the new guys coming into the hobby, those who brag the most about there education level are exactly that braggers, those who truly truly know don't have to brag..."

Is it bragging if one admits to graduating high school? :-)

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 28, 2007 Mail this to a friend!
Len: have you read chippy's bio, say no more, the guy's so full of crap his eyes are brown, have a good memorial day, N9FE
 
Antenna Lessons from the Old Timers  
by N1ONE on May 28, 2007 Mail this to a friend!
Great Article!

I learned this lesson first hand several months ago. I too was under the impression that a resonant antenna was the best way to go.

Don't get me wrong, if you intend to work only one band and cut the antenna for the middle of the sub-band you intend to work, then the resonant dipole feed with coax works just fine.

However, if you intend to work multiple bands with one antenna, then this article really speaks the truth.

I was using a 40 meter dipole feed with coax to a tuner. It worked well enough on 40 meters, but terrible every where else...even 15 meters was not that good.

I may not be the smartest HAM on the planet, but I am smart enough to ask for help when I need it. I asked one of the most experienced HAMS in the local club that I belong to. He told me to put up the longest dipole that I could fit in my yard, don't worry about the exact length, but make sure both legs are the same length. Ditch the coax and get some 300 ohm twinlead or 450 ohm ladder line. Feed that antenna system directly to the balanced line input on the tuner.

When I asked him why, he commented that a low SWR isn't always the most important thing. It is important, but it will be far less important if you have a low loss antenna system to begin with.

He was right! What a difference this new (and simple)antenna system made. I have been able work bands that were impossible for me to work the coax feed dipole. The signal reports I get are far better than before and I can work stations with far less power than I needed before.

This is an important lesson that all new General class HAMs should learn. Try it, it is the best way to learn something new!.

Thanks for posting this article!

73
de N1ONE
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
I am not aware of any inaccuracies in my bio, but I trust you will forward me corrections if I missed something.

In the meantime, the thrust of your comment is to attempt (unsuccessfully of course) to discredit my viability as someone who disagrees with the use of ladder line .

And, in the meantime, you have newbies who know NOTHING ABOUT THE SAFETY HAZARDS OF LADDER LINE based upon this article--which has YET TO BE CORRECTED despite the author's awareness of the issue.

That makes me 'full of crap'?

Well, I guess if I was basically a CB'er, I would be so threatened....I would use the aggressive and goofy antics of the CB 'hood.

But I am not.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
"...inherent to hardline"
--------------------------------------

No; correction to text: inherent to LADDER LINE.

See N4KC? It's EASY to correct text. So go do it on your article and WARN ABOUT THE SAFETY HAZARDS OF LADDER LINE.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
QRU.--N3OX
-----------------------------

That's the first intelligent thing I've seen you say in a while.

Understanding one's limitations is the first step to transcending them. Best of luck in your endeavors.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
And Chip: While I may be new to Amateur HF, I did cut my teeth in AM broadcast. Let's see if I remember the formula: 5kV * 1A / cow field @ .98MHz = 1 medium market C&W station

---------------------------------

Spreading the high lonesome. Boy, howdee!

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on May 28, 2007 Mail this to a friend!

You didn't spar with me; don't elevate yourself beyond your height OM. Or should I say young man?

73,
Chip W1YW


>> Chip, your pomposity is a tad off the chart. Ordinarily, I blow-off people who make these sort of comments as they usually emanate from people who have something to prove and aren't comfortable in their own skin.

Considering your background - yes, I've seen your bio and web site - I'm rather surprised. Most academics or scientists don't have time for this sort of thing. They are humbled by people who have an interest in their area of expertise and look up to them for assistance.

Something you may want to give some serious thought to......


WA1RNE

 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
You will find it worthwhile to discover, in life, that you have no right to define how others live, and they have no obligation to live up to some simplistic view of what you think they should be.

I didn't ask you to look at my bio. My suggestion is that if you find it offensive; false; over the top; and so on, then you make a formal complaint for it's removal. Personally, I couldn't care less if you read it or not.

Why should I?

I need to also add that your sense of vanity seems to be, IMO, Christian in origin, and not being a Christian, I do not feel the same compunctions: I didn't ask for your attention to my bio, but be damned if I will remove it to satisfy your mindset.

In any case, despite efforts to falsely discredit the messenger,I will continue to stress that the article at hand contains no information REGARDING THE HAZARDS TO SAFETY POSED BY ladder line, and that, IMO, the failure to correct it is a major disservice to the 'newbies'.

I hope this helps.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by AD5TD on May 28, 2007 Mail this to a friend!
Antenna Lessons from the Old Timers Reply
by NB9D on May 24, 2007 Mail this to a friend!
I have an old book entitled something like "Dipole and Longwire Antennas" that was published by 73 Magazine many years ago (in the 1970's I think) that is probably one of the best overall sources for simple antenna design you will find. I don't know where that book is available because I am sure it is out of print, but I find it a very good source for really down-to-earth data for wire antennas.

You didn't miss it by much. It was published in 1969 by Editors and Engineers Ltd. New Augusta Indiana.

I have the third priniting dated 1975. Great book

It's called: Dipole and Long-Wire Anennas by Edward M. Noll, W3FQJ
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 28, 2007 Mail this to a friend!
"You will find it worthwhile to discover, in life, that you have no right to define how others live, and they have no obligation to live up to some simplistic view of what you think they should be."

Take your own advice, Chip.

By your own arguments:

You have no right to define what technologies other hams use or don't use.

You have no right to define what is safe and what isn't.

You have no right to define what other hams should post and not post.

When you say that hams shouldn't use tubes, or ladder line, or anything else that is legal but not new technology, you are definining how others should live, and saying that they have an obligation to live up to your simplistic view of what they should be.

Play by your own rules, Chip. Or is it "do what Chip says, not what Chip does"?

 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
I claim no such right(s).

I exercise **privilege** in the context of this articles TITLE---Antenna Lessons from Old Timers-- to convey the reality: ladder line is a small niche of all ham antenna users; is not advantageous over coaxial feed systems; is inherently hazardous; safety cautions needed in initiating the newbie. And so on.

To reinforce this, I have just dug out a wonderful picture from the book DON WALLACE W6AM, showing a ham lighting a cigar from the arc drawn from the grounded portion of 9ZT's (W6AM's earlier station)ladder line. He was using less power than contemporary QRO stations BTW.

SWITCH TO SAFETY . Switch to coax.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
In the Cebik article, the table notes that on every band 80-10 the line loss is much less with ladder line than coax.

-------------------------------------
Hi Jim,

L.B. Cebik is a retired professor of aesthetics and art that has done, for the most part, (and unrelated to his profession) a fine job of preserving knowledge on ancient antenna designs, IMO. I think it's a fine past-time for one in their retirement. I also think that many have learned some important antenna basics from his voluminous writings.

However, IF he is telling you that coax has significantly higher insertion loss at HF and MF than ladder line, the measured results are contrary to that statement. The typical insertion loss for a 100 feet of good coax at MF is of order less than a dB. I know, because I measure insertion loss all the time on vector network analyzers. I measure the insertion loss of every piece of coax I use. I have consistently found the actual insertion losses to be better than spec.

So please: can we dispel this myth that coax is "lossy"? Crap coax is lossy. Good coax, and great coax is not.

So don't use crap coax.

End of story.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by KA4KOE on May 28, 2007 Mail this to a friend!
I use ladder line. It works. I make contacts. Its my decision. I am of voting age (plus some).

As long as I don't infringe upon someone else's space or safety, who cares?

PAN
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
Hi 'PAN',

Good attitude, reasonable comment.

I do hope you agree that anyone doing as you say have some prior knowledge about keeping ladder line away from metal, and proper grounding and breaking for lightning. These are just common sense safety warnings that every neophyte should know; don't you agree?

Wouldn't you also agree that some intro article for the neophyte include such warnings, and that any reasonable author should add such text if brought to their attention?

73,
Chip W1YW

 
Antenna Lessons from the Old Timers  
by AB7E on May 28, 2007 Mail this to a friend!

What a silly, totally subjective, horribly verbose article. Almost five thousand words to say virtually nothing.

Of course there is no inherent benefit to having a resonant antenna, except that there are strong pattern benefits to making it an appropriate length for the band being operated. But neither is there any compelling reason to "do it like the old timers did", and there are few good reasons for trying to avoid a resonant antenna. There are loss advantages to controlling feedpoint impedances, even with ladder line, and even well built tuners can create a lot of loss trying to drive the wrong loads.

This kind of simplistic posting and most of the replies it spawned create way more misconceptions than our hobby needs. It perpetuates the mentality of following vague and inappropriate rules of thumb versus simple (and mostly free) analytical analysis of the particular situation at hand.
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 28, 2007 Mail this to a friend!
N9FE: "Len: have you read chippy's bio, say no more, the guy's so full of crap his eyes are brown, have a good memorial day, N9FE"

If you meant me (AF6AY), yes I have. Am I impressed with W1YW's biography on QRZ? Yes. Now what, you want to FIGHT on Memorial Day over some very personal feedline choice used in amateur radio HF ham antenna derring-do?!?

You want to "fight?" Okay, you grab the hardest, toughest 450 ladder-line (TV twinlead on steroids) and I will face you with some Andrew 1 5/8" coaxial hardline (with or without the "bullets"). Think you will win? I don't think so.

Memorial Day is a day of remembrance for those who fell in the service of their country. I am a veteran of the US Army. I don't have "good" or "bad" Memorial Days. I mentally salute all my comrades in arms whether they served before or after me. I don't take any snit from some who want to "enlist me" in some idotic personal vendetta over computer-modem communications and their poor feelings being so hurt.

I lucked out on my Army assignment. It turned out to change my working career choice. To see why, you are welcome to download a photo essay of my three years of Army service in HF communications at a Big HF Station over a half century ago: http://sujan.hallikainen.org/BroadcastHistory/uploads/My3Years.pdf
Approximately 6 MB file size, 20 pages. It has lots of nice pictures in it if the text gets too technical for you. It has been vetted by N2JTV who served with me at the same station at the same time I did (but on a different operating team) and a civilian engineer (now retired) who worked for the Army there. That was a long time ago and the Era of the Tube. Times have changed and technology has changed by several orders of magnitude in the last half century. Learn with it or die the Darwinian Way.

Now, I happen to agree with Chip on his choice of coaxial cable versus TV twinlead on steroids ("ladder line"). Try to remember what the subject of the article, forget your petty spats. My eyes are blue. My blood is red. My race is "white." This is Memorial Day in the USA. My stars and stripes are flying in front of my house today in honor of those who never came back. Is yours?

Len AF6AY [ex-RA16408336]
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 28, 2007 Mail this to a friend!
Wow! Absoultely amazing! Next they will be fighting about which is better, Upper Sideband or Lower Sideband.

Have a Happy Memorial Day, and don't forget our Troops
fighting, so we can enjoy this nice day off!

73 de W4LGH - Alan
http://www.w4lgh.com
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 28, 2007 Mail this to a friend!
"Wow! Absoultely amazing! Next they will be fighting about which is better, Upper Sideband or Lower Sideband."

Listen up, "Alan" (if that is your real name), my brother was KILLED by Lower Sideband so if there ever was a reason to hate LSB, this is enough for me.

How come nobody posts about the horrible dangers of Lower Sideband? Huh?

Got it?!?

Oh, and "73!"
Steve N4SL
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
Memorial Day is a day of remembrance for those who fell in the service of their country. I am a veteran of the US Army. I don't have "good" or "bad" Memorial Days. I mentally salute all my comrades in arms whether they served before or after me. I don't take any snit from some who want to "enlist me" in some idotic personal vendetta over computer-modem communications and their poor feelings being so hurt.

--------------------------------------------

Thank you for protecting our country.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
This kind of simplistic posting and most of the replies it spawned create way more misconceptions than our hobby needs. It perpetuates the mentality of following vague and inappropriate rules of thumb versus simple (and mostly free) analytical analysis of the particular situation at hand.

-------------------
Exactly.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 28, 2007 Mail this to a friend!
"Len: have you read chippy's bio, say no more, the guy's so full of crap his eyes are brown.."
------------------------

My eyes are green.
 
RE: Antenna Lessons from the Old Timers  
by KG6R on May 28, 2007 Mail this to a friend!
Hi Nathan,

According to you, Mr. Cebik a renown antenna expert and the editors of the ARRL antenna book are wrong to point out that a good choice for a feedline for a multiband dipole doublet is twinlead.

So what?

Empirical evidence proves that this is a useful antenna for some folks. It has been used for decades. It is still being sold by reputable antenna manufacturers.

Why would I want to purchase comparable loss coax at a greater expense than twinlead which costs considerably less? For this particular antenna, twinlead works better as a feedline than comparably priced coax. Safety is always an issue that has to be taken into account for any design. I have and as a result never had a safety issue with twinlead.

You are willing to pay more to use coax. That is fine with me. After all, this is still America, or is it?

73 de KG6R,

Jim


YOU WROTE.....

So please: can we dispel this myth that coax is "lossy"? Crap coax is lossy. Good coax, and great coax is not.

So don't use crap coax.
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 28, 2007 Mail this to a friend!
Yes my flag is flying, my son is still in iraq for two years now, his dad is sitting here in a wheelchair, you all have a good day.. N9FE
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 28, 2007 Mail this to a friend!
I love it!

AF6AY says....
"First lesson: ANY piece of wire will radiate RF if fed properly."

This is 100% correct, just like 50 turns of wire glued on any piece of paper and held ove a PM magnet will make audio...of some kind, but do you want to use it?

The military is NOT a good example to use for coming up with a way to use HF radio effeciently! There was nothing good about any of the PRC radios and/or their antennas! At best they had about a 10 mile range when used with the attached antenna. Has something to do with that oxymoron "Military Intelligence" and their newest..a real classic.. an "Army of One!"

One day someone will come up with a better way to effectively couple/de-couple RF energy to/from our atmosphere. As for now the antenna is still pretty much the same as it was 100years ago. Wow, imagine what it would be like if EVERYTHING stayed the same over the past 100years. There will be a break thru one day, then maybe they will come up with a replacement for a gas engine..another 100 year old technology.

73 es Hope everyone had a great Holiday weekend, and thanked a soldier!

Now its 10pm eastern...do you know where your kids are?

de W4LGH - Alan
 
RE: Antenna Lessons from the Old Timers  
by W7ETA on May 28, 2007 Mail this to a friend!
IF we all asked politely, would eHam make a section where these experts can all go to pee on each other legs so that someone who might want to learn more about the subject matter does not have to wade through excrement?

Bob
 
RE: Antenna Lessons from the Old Timers  
by K5MVP on May 29, 2007 Mail this to a friend!
It really is very simple. Open wire line equals very low loss resulting in over 95% of your power to the antenna. However, the big secret is using a true balanced antenna tuner like the Johnson Matchbox and NOT using baluns anywhere in the antenna system. For starters cut yourself a G5RV antenna which is 51 feet on each leg. Connect it to 450 ohm balanced line and connect the other end of the balance line to the Johnson Matchbox. Put the antenna up as high as possible. You will work the world with one antenna on all bands. You will work DX in large pileups. You will have no RF in the shack and you will have spent very little for an antenna which performs beautifully and is a dream to maintain.

“What goes around comes around”. Yes, we can all learn if we have an open mind.
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 29, 2007 Mail this to a friend!
After 50 years ham radio I would wholeheartedly agree with the last post from K5MVP, and it is so clearly expressed.
After using all types of antenna, 100 ft towers, rotators, Yagis and Quads, I have reached the same conclusions.
I wondered how to celebrate 50 years on ham radio and on my Anniversary I worked Peter 1 Island using exactly the system K5MVP advocates.
In fact I have two G5RVs 30 degrees apart so I can choose one which has a main lobe where I want to work, but usually I only use the one antenna.
The 100ft twin 300 ohm feeder from RadioShack is the best bargain known.
No baluns, no coax. Sleep during night-time hurricanes.
The Matchbox is the best thing I ever bought.
Buffalo Gil Dr Gil W2/G3LBS
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
You guys still don't get it. SO let me spell it out for you:

1) the insertion loss of good coax is low, even very low, so claims that ladder line is truly superior in this regard are false;

2) MISMATCH loss can obviously be higher with 50 ohm coax on a 'non resonant', because coax was made to be fed at the CURRENT MAX of a real-world 1/2 wave dipole (which is about 50 ohms) and...

3) These so-called 'non resonant' antennas are not fed at the CURRENT MAX (at least in the ham bands), so the feed impedance is far from 50 ohms real;

4) the feed impedance goes UP away from the position of the current max on the antenna, so anything that that has a characteristic impedance of a few hundred ohms for a feed will have less mismatch loss at the FEED POINT;

5) you still need to transform and, presumably, conjugate, the impedance of the ladder line at the exciter, which is designed to see a 50 ohm real load in modern transceivers.

6)I can make 50 ohm ladder line, and it will inherently suck against coax on ALL counts: I can also BUY--although not common-- coax with a higher characteristic impedance that will have less mismatch loss on this 'non resonant' antenna. In any case LADDER LINE WILL ALWAYS BE WORSE for a given cost per foot.

There is nothing magic or superior about LADDER LINE--

**** THE ISSUE IS THE CHARACTERISTIC IMPEDANCE OF THE FEEDLINE VERSUS THE IMPEDANCE OF THE FEEDPOINT OF THE ANTENNA.***

OK?

Stop ACTING like amateurs...

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!

It really is very simple. Open wire line equals very low loss resulting in over 95% of your power to the antenna. --K5MVP

----------------------

Can we PLEASE stop promulgating myths? There is nothing about ladder line (open wire) feeds that makes them inherently less lossy.

Insertion loss depends on the materials, separations, conductor width and material,and so on.

I can have crap ladder line, and I can have great coax.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 29, 2007 Mail this to a friend!
G3LBS: you are exactly right, balanced line systems are great, the best thing is 80 percent of your power is NOT coming back down the coax shield as loss, but don't tell everyone, then maybe someone just might hear them,
 
RE: Antenna Lessons from the Old Timers  
by KA4NMA on May 29, 2007 Mail this to a friend!
Concerning ladder line safety, a few years ago QST ran a series of articles on grounding (written by a Mr. Block, whose brother founded PolyPhaser) on grounds and safety. The article tells how to use gas discharge units on ladderline. Reprints are available from the ARRL website.

Also, the wireman sells a lighting arrestor for ladder line.

Also, check the tables for coax and ladder line and compare the loss per 100 ft. Ladder line has lower loss.

Guess the "experts" are not so well read.
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
Guess the "experts" are not so well read.

-----------------------------------------------
No OM; it is you who has not "read".

Please review my comments on coaxial cable loss.

As an expert (I apologize if that offends you) I would be happy to articulate, in detail, how to MEASURE the insertion loss of a length of coax. Using a vector network analyzer.

If you "read" you will see that all coax I have measured, that is not used and hence 'crap',is low loss at MF/HF and is better than specs--i.e. your 'table'.

I hope that helps.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
Concerning ladder line safety, a few years ago QST ran a series of articles on grounding (written by a Mr. Block, whose brother founded PolyPhaser) on grounds and safety. The article tells how to use gas discharge units on ladderline. Reprints are available from the ARRL website...

-----------------------------------

That's great...now: don't you think NEWBIES should be given the SAFETY CONCERNS AND OPTIONS in any and ALL **intro** articles on ladder line?

Why is it NOT in this article?

Why has the author NOT REVISED to include?

Is SAFETY such a MINOR CONCERN FOR our newbies that we wish them to TAKE RISKS we wouldn't?

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 29, 2007 Mail this to a friend!
W1YW wrote:

"1) the insertion loss of good coax is low, even very low, so claims that ladder line is truly superior in this regard are false;"

The loss of an equal length of good ladder line (not window line, not TV twinlead) is even lower. So good ladder line *is* truly superior in this regard.

"2) MISMATCH loss can obviously be higher with 50 ohm coax on a 'non resonant',"

That's true because, with any transmission line, the added loss due to SWR is dependent on the loss when matched.

"because coax was made to be fed at the CURRENT MAX of a real-world 1/2 wave dipole (which is about 50 ohms)"

No, that's not why coax is 50 ohms.

The reason coax is 50 ohms dates back to when flexible, polyethylene-dielectric coax cables were first developed. Turns out that, for a given amount of copper and poly, the loss-per-unit-length of such coax goes through a broad minimum around 50 ohms. For air-insulated coax, the minimum is around 77 ohms. For foam-insulated coax, it's in between those values.

Look it up. There's a reason you don't see 300 ohm solid-poly coax - it's called loss.

That a center-fed half-wave HF dipole erected at certain heights above ground has a feedpoint impedance around 50 ohms is pure coincidence.

"3) These so-called 'non resonant' antennas are not fed at the CURRENT MAX (at least in the ham bands), so the feed impedance is far from 50 ohms real;"

That's true - but it doesn't tell the whole story.

We amateurs are fortunate to have access to a 9 HF/MF bands, plus some channels near 5 MHz. And all US amateurs have access to at least 4 of those bands. An increasing number have access to all 9 bands.

But many of us do not have the resources to put up
separate antennas for each band, or even for a couple of the bands. Many do not have the space to put up full-sized half-wave antennas for the lower HF bands.

So we're forced to come up with compromise antennas. The trick is to find the best compromise for a given situation.

For example, I once lived in a house that was at the front of a narrow-but-deep lot (46 feet wide, 275 feet deep.). There was a huge tree in the back yard. So I ran an end-fed wire (well insulated) out the basement window, up the side of the house to the attic window, and out across the yard to the tree. End-fed the wire against ground using a simple L network tuner. Did a really good job on all HF bands.

What coax-fed antenna should I have used instead?


Earlier in this thread, I have twice described a scenario where an amateur would have the resources to put up a center-fed dipole 100 to 130 feet long between existing trees. I suggested feeding it with good ladder line and a good balanced tuner, so that all HF bands could be covered with a single antenna. And I challenged you and anyone else to describe a better setup for the given location that used only coax feed.

So far, no takers.

"4) the feed impedance goes UP away from the position of the current max on the antenna, so anything that that has a characteristic impedance of a few hundred ohms for a feed will have less mismatch loss at the FEED POINT;"

That's true. But it's not the whole story. Feedpoint Z also goes up on harmonics, and varies with antenna height above ground.

"5) you still need to transform and, presumably, conjugate, the impedance of the ladder line at the exciter, which is designed to see a 50 ohm real load in modern transceivers."

And that's the job of a transmatch, aka tuner. So what? Simply feeding a halfwave dipole with coax will not eliminate the need for a matching device on bands such as 160, 80/75 and 40 meters.

"6)I can make 50 ohm ladder line, and it will inherently suck against coax on ALL counts:"

Then don't make it.

" I can also BUY--although not common-- coax with a higher characteristic impedance that will have less mismatch loss on this 'non resonant' antenna. In any case LADDER LINE WILL ALWAYS BE WORSE for a given cost per foot."

Sorry, that's simply not the case. Check out W5DXP's all-HF-band no-tuner antenna for an example.

"There is nothing magic or superior about LADDER LINE--
**** THE ISSUE IS THE CHARACTERISTIC IMPEDANCE OF THE FEEDLINE VERSUS THE IMPEDANCE OF THE FEEDPOINT OF THE ANTENNA.***

OK?"

Nope.

Ladder line, coax, tuners, matching sections, baluns, ununs, and many other things are simply tools in the amateur's antenna system toolbox. Some are old tools, some are new tools. All are useful. All have their good points and bad points, their uses and abuses.

The trick is finding the best tools for a given scenario.

Now, Chip, if you're the "expert", please scroll up this thread to where I described the scenario of the ham whose house is in the middle of the lot with trees near the edges. Read that scenario and tell me what sort of simple, coax-fed antenna could be put up at that ham's QTH that would do a better job than the ladder-line-fed dipole I described. Remember that it would have to do a better job on all amateur HF bands from 80 through 10 meters *and* meet all the requirements and conditions described.

All other "experts" are invited to solve the same problem.

Anyone?

"Stop ACTING like amateurs..."

Well, if the behavior of some here is supposed to be PROFESSIONAL, I rather prefer those who act like amateurs.

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
I rather prefer those who act like amateurs.

73 de Jim, N2EY

----------------------------------------

I can see that. You definitely shouldn't prefer me. Please keep me off your QSO list-just turn the dial if you hear me.

And you are wrong about 50 ohms: for decades it has been possible (and done) to make cheap, low loss coax that is far from 50 ohms. The 50 ohm 'standard' was adopted because of the antenna drive impedance-not coaxial dielectric.

And hey! You are wrong about lots of other stuff too, as far as I can see.

But thanks for turning my words around to make them address something different.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 29, 2007 Mail this to a friend!
Gentlemen, we have a winner by default.
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 29, 2007 Mail this to a friend!
even on a resonant cut dipole what is the shield side of the coax doing chippy,,,, thats right nothing,, if anything the energy is be wasted "loss" and coming back down the coax and grounding out on the back of the radio, or tuner, the grounded out "shield" side of the coax does nothing, a balanced line system the energy flows both ways, hence a better signal, a smart guy like you should know that, also a truly balanced system, the feedline does NOT radiate, NOT one bit, hence no TVI, and a better signal for all to hear you with, these are not myths, these are facts, well proven facts, N9FE
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on May 29, 2007 Mail this to a friend!

"You will find it worthwhile to discover, in life, that you have no right to define how others live, and they have no obligation to live up to some simplistic view of what you think they should be."


>>> You need to take a good look at most of your posts – and in the mirror as you seem to have a very convoluted sense of entitlement. On one hand, you don't mind telling others what is or what isn't correct but should someone even insinuate providing the same advice you, they’re overly simplistic. Sooner or later, I think you will find in life that such double standards come back to bite one in the a- -.


"I didn't ask you to look at my bio. My suggestion is that if you find it offensive; false; over the top; and so on, then you make a formal complaint for it's removal. Personally, I couldn't care less if you read it or not. Why should I?"


>>> That’s right, you didn’t; I checked you out - so what? Why would I ask to have your bio removed? I never said there was anything wrong with it –or is there?? Other than a distasteful amount of rodomontading, I wouldn’t have any reason to complain.


"I need to also add that your sense of vanity seems to be, IMO, Christian in origin, and not being a Christian, I do not feel the same compunctions: I didn't ask for your attention to my bio, but be damned if I will remove it to satisfy your mindset."


>>> Being a Christian, I’ll take that as a compliment, thanks. Once again, you may not have asked for my attention to your bio, but your acutely ostentatious style brings out the best in me. In all honesty, I could really give two craps about what you do with your “bio”. As to whether or not YOU, Nathan Cohen feel the compunction to be vain; gee going by your other posts, I think you've already let the cat out of the bag, don't you?


"In any case, despite efforts to falsely discredit the messenger, I will continue to stress that the article at hand contains no information REGARDING THE HAZARDS TO SAFETY POSED BY ladder line, and that, IMO, the failure to correct it is a major disservice to the "newbies". I hope this helps."


>>> Really Chip, is “help” the right choice of words here? If you really wanted to help, we’d find your postings all over the Elmer’s forum, which of course we don’t. As your bio seems to indicate you are a tough act to follow, and by your recent responses here, a real piece of work.


....WA1RNE
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
Well, OM, if I BOTHER you oh so much, then why not just ignore me?

Why do you feel that you have to prove something?

Being a Christian, as you say, then ask the truly gracious question--no sarcasm meant in any way: What would Jesus do?

You are poor student of the New testament, IMO.
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
even on a resonant cut dipole what is the shield side of the coax doing chippy,,,, thats right nothing,, if anything the energy is be wasted "loss" and coming back down the coax and grounding out on the back of the radio, or tuner, the grounded out "shield" side of the coax does nothing, a balanced line system the energy flows both ways, hence a better signal, a smart guy like you should know that, also a truly balanced system, the feedline does NOT radiate, NOT one bit, hence no TVI, and a better signal for all to hear you with, these are not myths, these are facts, well proven facts, N9FE

-----------------------------------

I have no idea what this gibberish is trying to convey. It's typing, not writing.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 29, 2007 Mail this to a friend!
"rodomontading"

What a word! $16.50 at least.

Dan
 
RE: Antenna Lessons from the Old Timers  
by WB4TJH on May 29, 2007 Mail this to a friend!
From the way some of the silly old fools on this site are going at each other, I would suspect the Prozac has run out or the Geritol bottle is empty. Give me a break.
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
It's that 'CB-morphing' of ham radio--in action.

Damn shame.
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 29, 2007 Mail this to a friend!
N9FE: "even on a resonant cut dipole what is the shield side of the coax doing chippy,,,, thats right nothing,, if anything the energy is be wasted "loss" and coming back down the coax and grounding out on the back of the radio, or tuner, the grounded out "shield" side of the coax does nothing, a balanced line system the energy flows both ways, hence a better signal, a smart guy like you should know that, also a truly balanced system, the feedline does NOT radiate, NOT one bit, hence no TVI, and a better signal for all to hear you with, these are not myths, these are facts, well proven facts, N9FE"

Proven fact: A dipole is a balanced system.

Proven fact: Coaxial cable is an unblanced system.

Proven fact: You cannot connect balanced systems directly to unbalanced systems and expect them to work perfectly together.

To cure Proven Fact 3, there is the very simple broadband RF transformer called a Balun. After the balanced to unbalanced transformation is done, there is no RF radiation from the outer conductor of the coaxial cable. Depending on the insulation resistance of the Balun internal structure, there will be no bleeding over of electrical storm static electricity build-ups to the ground.

Proven fact: A broadband RF transformer Balun will transform the complex impedance of the balanced dipole to the unbalanced coaxial cable system directly in accord with its transformation ratio.

Proven fact: Classic/legacy dipoles have resistive-only impedances only at their 'resonant' frequency. Away from such 'resonance' frequency, both resistive and reactive values vary considerably.

Proven fact: Classic/legacy dipoles will radiate RF at ALL frequencies...but the radiation pattern will vary from the 'resonant' frequency shape, both horizontally and vertically.

Proven facts 4 and 5 can be solved for a resistive-only impedance transformation over a wide frequency range using an unbalanced input/output "antenna tuning unit" (either manual or automatic). Proven fact 6 can't be solved by using balanced or unbalanced feedlines or antenna tuning units.

Proven fact: RF sources (such as transmitters) are designed for and tested with unblanced resistive-only loads. Nearly all such RF sources will refuse to deliver resistive-only-load RF power output to loads with unmatched impedances (i.e., resistive part of impedance not close to design resistance and/or reactive part of impedance is non-zero).

Proven fact 7 can be cured in a variety of ways, by using an "antenna tuner" (impedance transformation device) or "tuned feedlines" (cut to a specific wavelength). The latter is very narrowband, the former can be very broadband.

Those facts should be well known but, in some insane need to be competitive while fighting some Word War 3, there is failure to cite ALL the facts. Let's use ALL the "proven facts," okay?

73, Len AF6AY

 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 29, 2007 Mail this to a friend!
AF6AY: "First lesson: ANY piece of wire will radiate RF if fed properly."

W4LGH: "This is 100% correct, just like 50 turns of wire glued on any piece of paper and held ove a PM magnet will make audio...of some kind, but do you want to use it?

I don't know about the number of turns, but it seems I've listened to paper cone speakers with their coils of wire in an air gap in a magnetic field all my life. [I've always been older than the FCC]

W4LGH: "The military is NOT a good example to use for coming up with a way to use HF radio effeciently!

Just what is your definition of "efficiently?" Do you think the militaries of the world operate according to amateur radio use specifications?!? Is there a UN QSL "buro?" Does the ITU-R sanction radio contests? I don't think so.

I cited the current US military manpack HF radio transceiver, the AN/PRC-104. Completly portable, it will work "QRP" anywhere in the HF spectrum, in environments that far exceed what ham radio users care to tolerate. The Receiver-Transmitter of the PRC-104 is the very same one used with a vehicular system and with a field fixed radio set, maximum PEP output of 450 Watts into a choice of antennas.

The PRC-104 is almost a quarter-century old, operationally. The US Army is currently looking for a replacement. If you wait a few years, maybe you could get a nice little QRP transceiver of 20 W PEP with attached automatic antenna tuning unit, all portable from rechargeable LiON batteries. Surplus, of course...write your elected Representative or Senator to remind tham that all no-longer-used HF radios should be sold below-cost to the "deserving" citizens who love slamming/hating the Army.

W4LGH: "There was nothing good about any of the PRC radios and/or their antennas!"

:-) Up your feedline too, fella. I wore an AN/PRC-8 a few times, high-HF/low-VHF, all tubes, dry battery pack only, whip antenna, audio output enough to be heard through the earphone of the handset clipped to the pack straps. It was VFO-tuned, just like the WW2 predecessor SCR-300 (first manpack "walkie talkie"). Worked just fine for its intended purpose. Of course I didn't know that anyone was expecting QSLs or holding "contests" on how many other PRCs they could contact...:-)

The AN/PRC-6 handheld transceiver was also good but only VHF and tuned to a single R/T frequency with a crystal. First time I'd seen a tape-measure-metal-material used as an antenna. 13 tubes, all but one a subminiature. Good for a mile range in any terrain. Much better operationaly than the old WW2 HF handie-talkie. It also had a little "repeater kit" that let one connect two of them for unattended reapeater operation! [in 1952 no less :-) ]

During the Vietnam War there were the AN/PRC-25 and PRC-77 "channelized" VHF transceivers, much despised by true HF hams who absolutely hated VHF, Vietnam, the draft, and nearly everything else. The PRC-77 was all solid state, the PRC-25 had one tube for the Tx PA, both the same specs otherwise. Wasn't good for moonbounce or DX and I never heard of "Charlie" sending QSLs. An eighth of a million of those two transceivers were built worldwide (several militaries built them on license).

By 1989 the first of the SINCGARS were operational. 30 to 88 MHz, digitized voice and/or data, capable of frequency-hopping 10 carrier frequencies a second, in-clear or on-line-encrypted (encryption built in on later models). The AN/PRC-119 (manpack version) was eventually made in half the size and weight, the R/T used in higher-RF-power vehicular, airborne, and fixed radio sets. One of the first field radio sets to use rechargeable batteries. Not a chance to QSL those transmissions. Absolutely NOT a "real [HF] radio" since it didn't even have a frequency-control knob or switch! [it's got an LCD touch-panel for entering the "hopset" as well as diagnostic indicators]

For that matter, the US military doesn't even come close to using HF tactically as it did right after WW2's end. Military land forces had migrated to VHF for the majority of small-forces communications on land during WW2.

W4LGH: "At best they had about a 10 mile range when used with the attached antenna."

No problem. Takes at least three hours to traverse 10 miles with a 70-pound load of sidearm, ammo, pack, field rations...while unfriendlies might be waiting to kill you all along the way. The "attached antenna" can reach out at lot faster, contact nearby units, aircraft. Is that how US ham radio is practiced? I don't think so.

W4LGH: "Has something to do with that oxymoron "Military Intelligence" and their newest..a real classic.. an "Army of One!"

The US military hasn't taught morse code for tactical radio use for decades. The very last place for military morse code training IS the Military Intellignece school at Fort Huachuca, AZ. All the service branches use that school for their military intelligence specialists, even the US government. Fort Huachuca also has the UAV school with a field outside the Fort. M.I. duties are NOT the ones practiced by our politicians who are the ones sending our troops everywhich way for whatever whim.

There hasn't been ANY military draft since the end of the Vietnam War, over 33 years of time. If you don't like the recruiting methods or sales slogans, go into your nearest recruiting center and beat up one of those "Army of One" guys. Good luck on your recovery. Let's stick to ANTENNA subjects for this article, okay?

W4LGH: "One day someone will come up with a better way to effectively couple/de-couple RF energy to/from our atmosphere."

News flash: Antennas work just fine in space, in total vacuum, no 'atmosphere' needed.

W4LGH: "As for now the antenna is still pretty much the same as it was 100years ago."

Really? Ever see the JPL Deep Space Network at Goldstone? There were parabolic reflectors in 1907? Messrs Yagi and Uda didn't come up with the parasitic-element beam antenna until the late 1930s in Japan. I'm not sure when the log-periodic broadband (no matching needed) antenna was invented but I saw a USN military log-periodic rotatable beam in eastern PA in 1971. The same for the "slot" antenna used in lightweight microwave antennas such as civil avionics weather radar...which RCA Commercial Aviation subdivision was making in 1974. The Discone is a widely-used broadband VHF-UHF omnidirectional antenna and it was first written up around 1953. Maybe you've never heard of the DDRR (Directional Discontinuity Ring Radiator) once touted by a Northrup division (?) in the late 1950s, a much smaller HF antenna of very low height...kind of fell out of favor, maybe because it was as narrowband as a conventional dipole...or maybe because it didn't look like an HF antenna? How about the RCA Turnstile antenna for TV and FM broadcasting? [not HF, therefore not a "real" antenna] How about the "leaky wave" antennas used in tunnels for passive rebroadcasting or cell phone use?

Okay, how about the Folded Dipole? Yields some broadbandedness over conventional dipole (it can be made from 300 Ohm twinlead or twinlead-on-steroids called "ladder-line"). How about the Loop Antenna? [I don't know who was the first to characterize that one but I can't remember it being used in 1907] How about the "Loopstick" in table-model radios? [there wasn't any such thing as a 5-tube "table model radio" in 1907] How about the Square-Corner Reflector or the Ground Plane vertical (the one with the "droopy" ground radials)? How about the millions of broadband TV receiving antennas made and sold in the USA? How about the REAL MAN'S DX Antenna, the Rhombic? Maybe the two-wire Vee antenna? Kind of hard to envision anyone working up an appetite for Vees in 1907 when the common wavelengths were so long it took a LOT of copper wire to make one longwire back then.

If it were up to me, I'd rate the SteppIR as one of the first absolutely great INNOVATIONS in antennas of this new century. Imagine a 1907 antenna whose length could be sized to fit a frequency...by a stepper motor controlled by a microprocessor...slavable automatically to some modern transceivers' frequency control...and inside a protective fiberglass tube. A SteppIR yagi only needs to rotate 180 degrees; the director and reflector elements can change to reverse a beam direction. Brilliant!

W4LGH: "Wow, imagine what it would be like if EVERYTHING stayed the same over the past 100years."

I don't have to imagine. I just have to come in here and see "back to the past triumphant." :-(

W4LGH: "There will be a break thru one day, then maybe they will come up with a replacement for a gas engine..another 100 year old technology."

Another news flash: A German fella name of Diesel already did. But it doesn't work on 40m any better than the gasoline engine did. How about we stick close to antennas in this article? Or is everyone wanting to combust internally in here?

73, Len AF6AY

 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 29, 2007 Mail this to a friend!
KA4NMA: "Concerning ladder line safety, a few years ago QST ran a series of articles on grounding (written by a Mr. Block, whose brother founded PolyPhaser) on grounds and safety. The article tells how to use gas discharge units on ladderline. Reprints are available from the ARRL website."

It's double the gas discharge units inside those. Coax "arresters" use only one. Check the replacement part costs for those gas discharge units.

"Also, the wireman sells a lighting arrestor for ladder line."

No sweat...if a lightning strike hits a wire antenna direct, balanced polyethylene feedline will readily show where it blew apart...

"Also, check the tables for coax and ladder line and compare the loss per 100 ft. Ladder line has lower loss."

By HOW MUCH?

"Guess the "experts" are not so well read."

Ya know, I spent some time today looking specifically for ladder-line loss figures. Ya know what, the ONLY thing I found on ladder-line was in a paper that Wes Stewart wrote up, him using a VNA to get those figures. Chip uses a VNA to get his loss figures.

I even looked for TV twinlead specs and couldn't find any loss figures for that, either.

Where are all the "expert" tables from MAKERS?

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 29, 2007 Mail this to a friend!
W1YW: "Stop ACTING like amateurs..."

N2EY: "Well, if the behavior of some here is supposed to be PROFESSIONAL, I rather prefer those who act like amateurs."

News flash: Electrons, fields and waves work by Their rules...not by whether one is a "professional" or an "amateur."

Don't get so honked up by "professionals" even if you are one in the railway signalling works. :-(

Electrons, fields, and waves all work the same regardless of how many degrees one has, how many ham radio contests one wins, ones license class, or whether or not one has been licensed since the year dot. The FCC defines AMATEUR radio service as a licensed radio activity NOT involving pecuniary interest.

Some of us DO or HAVE DONE radio-related work, like for money. If you want to brat on us and refuse to accept insights or advice on matters radio, then YOU are acting like an amateur amateur.

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 29, 2007 Mail this to a friend!
"Ya know, I spent some time today looking specifically for ladder-line loss figures. Ya know what, the ONLY thing I found on ladder-line was in a paper that Wes Stewart wrote up, him using a VNA to get those figures. Chip uses a VNA to get his loss figures.

I even looked for TV twinlead specs and couldn't find any loss figures for that, either.

Where are all the "expert" tables from MAKERS?"

--------------------------------------------------------

Len, the ARRL handbook has tables of matched loss vs. frequency for a lot of different transmission lines. It also lets you calculate VSWR loss, which is where the comparisons get much more interesting.

Also this is fun:
http://www.ocarc.ca/coax.htm

Plus a lot of coax sites will publish the data in comparison tables.

I have exactly one antenna that is fed w/ coax, a 15m Lazy-H that is located where running real open wire feedline wouldn't work. I use Bury-Flex, I actually do bury it and it works great. Since the feedpoint Z is something crazy like 3000-J1000, I use a 1/4-wave matching stub made from homebrew 600 Ohm open wire line to get down to 50 Ohms.

For everything else, I use home made open wire line, 600 Ohm, w/ 14AWG 7-strand wire and 3/8" OD spreaders made from gardening irrigation tubing (very UV resistant). My multi-element phased wire arrays are strung out on long ropes hung from tall trees and running real QRO coax (I contest w/ 1500W) to their feedpoints is too heavy, causes too much sag. Especially the 500' long end-fed (33' short stub) zepp at 90' on 80 & 160m, that puppy boosted by Sweepstakes QSOs on 80m by triple.

So, it works perfectly for me and many other hams sans expensive, heavy coax (because good coax is both heavy and expensive and cheap coax is crap). The feedline isn't hard to make but is tedious to produce... and the neighbors always come over and ask some goofy questions which is fun.

For QRP field events, I use an 88' CF doublet fed with the same feedline only made from smaller, lighter copper-clad steel wire. The whole thing spools up on a plastic Christmas tree light spool and tosses into my backpack. This antenna is OK on 80, great on 40 and 20 and good but w/ a fragmented pattern on 15 and 10, all with one feedline and antenna.... and I can kink the feedline without damage, something that really matters in the field.

For FD, I have some commercial 450 Ohm 'ladder line' with the insulation and spacer tabs. This works well since it's lightweight, strong, doesn't kink and doesn't get wet in late June. I use RG8-X for coax-fed antennas on FD, seems to be the best price/weight/loss tradeoff.

I changed over to real open wire line because it doesn't change between wet and dry (it does change with SNOW, but nothing a good firm SHAKE won't help).

For convenience of course, coax can't be beat, especially when feeding rotating antennas and for burying the feedline. At VHF/UHF I use coax, but I have used open wire line on 6m with good results, just had to wind a different balun than my 160-10m one.

No geeks have been harmed in the making or using of my open wire line, but I think I scared the crap out of a hummingbird once.

N4SL
 
Antenna Lessons from the Old Timers  
by W1YW on May 29, 2007 Mail this to a friend!
As much as I disagree with N4SL's approach, I found his post information-rich and helpful to those unfamiliar with ladder line.

Unlike, IMO, the article itself.

Perhaps he might have some additional suggestions for the newbies on protection against arcing; spark plug vs gas discharge ligtning protectors; etc.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N7YA on May 29, 2007 Mail this to a friend!
Chip,

Given the circumstances and the audience you have gathered, wouldnt it have been an equally wise statement to say "I dont approve of ladder line, there are safety issues to consider, but if you must, then do so with caution", then offer up some ideas for the populace regarding good measures of safety? granted, i wont disagree that you have offered ideas here, but it seems your very presence has ignited a brushfire, why is that?

I dont doubt your intelligence, I dont discredit your years in ham radio, I dont dispute your DXCC standings (which were not brought up, unless i missed it), I wont sling mud, or call names, or attempt to lessen anything you have done. Im simply trying to grasp your approach here in regards to everyone reading your entries on the forum.

What is your psychological strategy for teaching old and especially new in a manner that will be well received about the subject of antenna safety and efficiency, both of which are VERY important issues that we should all be a part of. Is there a better way to reach the people with your message? what is the game plan? why did this discussion get out of hand? Thanks.

73...Adam, N7YA
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 29, 2007 Mail this to a friend!
What are the dangers of using ladder-line please - have I been missing something?
It doesn't radiate if it is truly balanced - for example by a truly-balanced no-balun tuner like a Matchbox.
Gil
 
Don't use ladder line. Ever.  
by N0EW on May 29, 2007 Mail this to a friend!
> Don't use ladder line. Ever.

That is crazy talk. Ladder line or open wire works very well. It is like anything else, you have to understand both the pros and cons and how to apply the concept to your needs.

An "antenna" is just some wire (or pipe) laying in a box somewhere. An "antenna system" is what we use to communicate around the world! It certainly includes an antenna, but it also includes far more than just an "antenna". This point is always worth making because it is too easily overlooked.

As was mentioned in the article, read what W2DU ("Reflections II" by Walter Maxwell, W2DU, if you can find it) has to say, and read Cebik's web page. They are both very good sources of information, and Cebik's web page is loaded with "numbers" that our unlicensed friend was seeking.

My only wish would have been to see the phrase "impedance matching" in the article, but I assume he didn't want to open another can of worms.

All in all, a good article. Limited in scope. After all, entire books are written on this topic, so be fair when being critical of what is left out of short articles. This carried a somewhat amuzing tone, was easy to read, and a provided decent overview of a very practical and useful approach. Some may call it too simple, but it isn't to someone new to the concepts. We all have to learn somewhere, and this article does a good job of pointing his intended audience (our new Generals and Techs) in the right direction.

Thanks for the article. I enjoyed reading it.
73-Erik n0ew
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Hi Adam,

It has nothing to do with intelligence, save that trivializing the safety issues with ladder line is far from intelligent.

Once again, with feeling:

Don't use ladder line. Ever.

If you don't like 50 ohm coax then use a different characteristic impedance.

BTW, my rigs--all 3 of them--have 50 ohm ports. Unbalanced. No 300 ohm ladder line or 450 ohm ladder line connections in sight. I have a number of antennas that are from from 50 ohms real at the current max. I don't have any problems with coax or insertion loss.

Take a look at your rig. What is the port? What does it want to see? Why is there a convention of 50 or 52 ohms for it?

Now the SX-100 receiver--the one that hangs out as a conversation piece in the foyer--THAT has screw connections for ladder line. Of course, that's almost 60 years old, has a horrible noise figure--and is tubed.

If you are stumped as to how to make a multiband single wire antenna, coax-fed, well,maybe that's a good reason to exercise the mission of Part 97.

Don't you think?

Of course, we can all light our cigars off the arc of ladder line. Ooops...forgot: cancer risk too high.

It pays to be intelligent!


73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Adam--

You assert that this topic has gone out of hand...

Actually, I never went out of hand, but have meted my comments skillfully to get them across and to expose the muddled thinking about this subject. AF6AY and others did a pretty good job also.

Why did the topic take such an over the top flavor?
It probably has to do with a few things, that made me force many of you to re-think, and confront, your attitudes:

1) telling someone publicly and archivally they should die (in this case me) because I don't support this ladder line fetish;

2) telling someone that they are crazy; braggart; "full of crap"; and other tasty superlatives when in fact all they have done is provide factual responses to elaborate;

3)the absolute lack of comments in the article regarding SAFETY ISSUES with ladder line--and the trivialization of said SAFETY ISSUES in the follow-up comments.

Hope that helps. I'm feeling great about it.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 30, 2007 Mail this to a friend!
"Don't use ladder line. Ever."

Why not?

Why take a useful tool out of the toolbox?

"BTW, my rigs--all 3 of them--have 50 ohm ports. Unbalanced. No 300 ohm ladder line or 450 ohm ladder line connections in sight. I have a number of antennas that are from from 50 ohms real at the current max. I don't have any problems with coax or insertion loss."

That's nice.

Should hams not use BNC or N connectors, since most ham rigs don't have those connectors on them?

"Take a look at your rig. What is the port?"

My rigs don't have "ports". They do have antenna connections.

"What does it want to see? Why is there a convention of 50 or 52 ohms for it?"

Because it's easier and cheaper to build a rig to match a single, unbalanced impedance.

"If you are stumped as to how to make a multiband single wire antenna, coax-fed, well,maybe that's a good reason to exercise the mission of Part 97."

I'm not stumped on how to make a simple, effective, all-HF-band, single-wire center fed dipole. Or an end-fed wire, for that matter. I think *you* are stumped about how to do it with coax-only feed, but you don't want to admit that ladder line is better for that application.

You can prove me wrong, of course. You could describe a way to make a simple, effective, all-HF-band, single-wire center fed dipole that uses coax feed and is better than a similar ladder-line-fed antenna. But I don't think you or anybody else will - because you can't.

"Of course, we can all light our cigars off the arc of ladder line. Ooops...forgot: cancer risk too high."

So we should never ever use ladder line because there can be high voltages on it? Gee, what about things like insulation and preventing physical contact?

I guess we should ban lots of other antennas, too. For example, there can be high voltages on parts of most manufactured HF vertical antennas, so I gues we hams should never, ever use them. And there can be high voltages at the ends of long-wire, dipole and inverted V HF antennas, so we hams should never ever use them either, right?

"It pays to be intelligent!"

Yep - and statements like

"Don't use ladder line. Ever."

are simply not intelligent.

 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
What's lacking in intelligence here is the ability to read answers already provided.

And, since you prefer to be with those who ACT like amateurs, N2EY, I have removed myself from your scope of pals. Please honor my request.

To others: I have been very patient and forthcoming in leading you folks down the path of where the real issue lies--which is the MISMATCH loss, and the impedance of 'non resonants' versus the characteristic impedance of the feedline used.

Ladder line is inherently dangerous; requires extra safety precautions; requires an interface to match to the rig ports; and is not less lossy than good coax--despite the continued assertion of that myth on this thread.

So there are several reasons why one should never use ladder line. And, in fact, almost all hams DON'T use it-- and I have yet to see it used in the telecom and wireless arenas. At least in recent generations.

For those who do not view this as 'intelligent', then I again invoke the 'CB-morphing syndrome' observation: Classic case of ham radio becoming more and more like the aggressive, nasty, ignorant world of CB, that so many of us 'old timers' find distatsteful and so utterly 'un-ham'.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 30, 2007 Mail this to a friend!
Well I have been thru this arguement several times before. Nothing wrong with using ladder line as long as you know its good and bad points. When using ladder line to a matched tuner in your shack your antenna system starts at the tuner. Coax was developed to move your antenna system out of the shack
and your antenna system starts at the end of the coax at the antenna. To properly use a tuner with coax, the tuner needs to be AT the ANTENNA!! This will reduce the loss, keep the antenna imp. matched to the 50ohm coax, keep common mode currents off the coax and out of the shack!

I know there will be post contrary to what I have said, and you are certainly entitled to your opinion.
I personally like keeping my antenna systems away from the house and shack. Good coax is NOT lossy at HF frequencies. The difference in loss between a 100' run of good coax and ladder line would never be noticed. The convience of using good coax more than out weighs the downfalls of ladder line, and the loss of good coax is probably less than the loss in your high dollar tuner. Costs less too!

If you like using ladder line, and it works for you, then so be it. It is balanced in theory, but it IS part of your antenna system, and it does start at the tuner/match in your shack. If you use Coax, your antenna system is moved out of the shack, and starts at the feed of the antenna, therefore making a tuner at the shack end useless as far as tuning the antenna system, it will match the losses to the radio, but all the losses of the antenn system will still exsist,
but your radio will be happy.

This is how I see it, based on 40+ years of experience. These are my opions but are based of factual findings of my own practial experience, both professionally and with amateur radio

73 es I hope some of this has helped you make your decision.

de W4LGH - Alan
http://www.w4lgh.com

 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 30, 2007 Mail this to a friend!
"why did this discussion get out of hand? Thanks.

73...Adam, N7YA"

... hmm...

From the original article:

"Don't think these are hot topics? Then you have not been listening or reading! I'll leave the first two alone for now so I can foolishly—and at risk of “flaming,” personal attacks, and questions about my heritage—take on the third topic."

Dan
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
Unless this is just an internet pissing match, I'm stumped as to all the negative comments about 'ladder line'.

Remember, I have specific reasons for using it:

1) It's much lighter than QRO coax and in my special situation of large wire arrays hanging from long ropes stretched between tall trees, I can't afford the sag from heavy coax.

2) I have some unfriendly impedance antennas I need to multi-band, such as my 500' end-fed Zepp. This thing really rocks on 80 and 160m and no, I have no idea how to feed with this coax without putting a matching device up at the feedpoint... can't afford the weight.

3) My feedlines come up to a 2nd story window and pass through w/ a wooden insert and ceramic feedthru insulators to large knife switches. Nobody can touch them from inside or outside the house. I live in the country so I have no RFI/TVI issues to worry about, not even my own TV on an antenna has a problem except when I transmit 6m with... coax... which has nothing to do with it of course.

4) My transmatches are homebrew from high quality components. I can transmit 1500W continuous duty RTTY for 15 minutes, then place my hand on the components and the only thing not at ambient is the balun (6 core, 10AWG Thermalize wire) which is 'warm'. What's that, 20 Watts out of 1500? Very low loss.

Personally, I like the look of open wire transmission line in the air and it has far less wind resistance and catches your eye way less than the commercial 'windowed ladder line'.

If I had a tower, I'd have coax, but I kind of enjoyed winning the NW Division plaque for SSB Sweepstakes (QRP, 2006) with my own home-modeled and built antennas hanging from trees.

N4SL
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Personally, I like the look of open wire transmission line in the air

--------------------

As much as I am trying to understand this, it is exactly the issue I mention: you have a generation of newbies who want to differentiate ham radio from CB , Wifi, and freeband. To them, reverting to the ancient and outmoded methods of 1930's ham radio is something to be desired, because they don't have to think (hard) about it, and it melds them into a fantasy world of old time 'radio'. Kind of a virtual internet world, like Warcraft. Oddly, almost all of them avoid CW like the plague, so you obviously have THAT contradiction: 95% of QSO's in the 1930's were CW, because phone rigs were very expensive to homebrew..and it was all homebrew. No one had the money to be on phone, to speak of (pun intended).

IOW, to this new generation that is doing 'CB Morphing' of ham radio , ladder line IS 'radio'.

And I think that is a vast failure of acculturation into 2007 ham radio and Part 97's mission. Yes, I see that as major problem.

Is there an issue with using ladder line in your station? There is if one projects this as a typical 2007 ham station--which you haven't.

I think you've been very resourceful, but I still see no reason to use ladder line.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
Chippy the only person morphing this thread into something that it is not is you, you are a complete waste of time and space on this thread, the perfect example of a troll with nothing else better to do with himself..
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
I have explained my reasons for using open wire transmission line very clearly and sincerely and stand by not only the theory of it but the practice: I put out a great signal and win contests every year with it (both CW and SSB, QRO & QRP).

Your arguments don't make sense to me, what is the better solution to my somewhat unique situation?
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Chippy the only person morphing this thread into something that it is not is you, you are a complete waste of time and space on this thread, the perfect example of a troll with nothing else better to do with himself..
-----------------------------------------
Being a nice fellow, who is aware of your circumstances, I shall decline to comment on your 'example' OM. Now be nice and find something positive in the day to day.

Best wishes,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 30, 2007 Mail this to a friend!
Another reason for using ladder line is that you don't have to spend time putting on those redundant plugs and sockets and you don't have to spray your connections with black rubbish
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Your arguments don't make sense to me, what is the better solution to my somewhat unique situation?

-------------------------------------------

The problem is that you started with a premise of ladder line and them built a solution around it. The very fact that you use knife switches for antennas in QRP contests says a lot about 'need' versus 'want'.

I certainly can think of low loss coax, for example, that is thin, usable for QRP, and weighs less per foot than your ladder line.

If you had started with the premise of: I have THIS budget and THESE trees and need THIS performance coverage, you would not have automatically excluded coaxial solutions from your antenna farm. IMO you are glowing in the hoariness of it all. That's OK. I find it charming, albeit outdated.

It's a nice antenna farm; as I said I think you have been very resourceful. Take the compliment. No backhanded insult here at all.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
I use the exact same setup of radios and antennas systems for QRO and QRP, so naturally for QRP my station is wildly overbuilt... but not for 1500W.

The knife switches provide both disconnect and switching to multiple transmatches (SO2R station).

And yes, at this point it's a matter of pride that I beat people who have spent a lot more money on purchased antennas and towers than I.

I still don't understand what I should be doing differently for my situation.
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Problems are solved by options--not by assumptions. Read my previous post please.

Your antenna farm is a throw back to an antiquated era. Nice, but not modern in the better solutution that technology of the last 60 years offers.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
So, tell me where it could/should be improved.

I'm not asking for detailed analysis or design, just something concrete to think about. I have been known to change.
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
Answer the man chippy, the world wants to know
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
So, tell me where it could/should be improved.

I'm not asking for detailed analysis or design, just something concrete to think about. I have been known to change.

-----------------------------------

But that is EXACTLY the problem: to ** SOLVE ** a problem, you need to DEFINE it. When I plan out an antenna farm, I start with the plot plan; do a height analysis;topography analysis; propagation modeling; budget; sensitivity analysis of performance tradeoffs, and so on. Only when you get all the issues TOGETHER is it clear exactly WHAT PROBLEM is being attacked.

You didn't start from that perspective. And you didn't execute based upon it. Provide me with the twenty plus page white paper needed for background, and I will be glad to spend an afternoon giving you my thoughts.

Otherwise, your question lacks sincerity and is, well, amateurish.

In fact, let me suggest that you pull it together as a web page so all can see it.

Drop me a line when you have a first draft and I'll tell you what's missing in defining the PROBLEM.

73,
Chip W1YW

 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
Just as i said about five posts ago,BULLSHOOTER, and nothing but a BULLSHOOTER,
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
This is how antenna farms are properly devised OM.
Your denial of that approach definitely fits into the 'CB-Morphing Syndrome'.

Please tell us when and how long you were a CB'er; how long you have ben anti-technology; and whether you have ever read the Radio Amateur's Code..

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
"Otherwise, your question lacks sincerity and is, well, amateurish."

Why are you geting personal and insulting to someone asking a sincere question?
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
I've made my offer.

Time for your execution.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by AK2B on May 30, 2007 Mail this to a friend!
Odd choice of words.
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 30, 2007 Mail this to a friend!
Hey Nathan W1YW
With all the critiquing you do here of other’s and you obvious immense personal knowledge. Why don’t you publish some articles here in the forum for all us God fearing and not so righteous to read? You could begin with one all about proper feed line fundamentals and then move on to proper techniques of installing antenna systems.

Of course that leads into antenna fundamentals. God Yes God knows according to you we all need that. I am sure you can be a huge help to the many cb’ers that you liken to calling many of us to be true professional Amateurs. But I but you decline on this statement to provide us with your self induced all mightiness. Because you’re either to great of a person to enlighten the rest of us to your worldly vision’s or maybe because that fact you were born in bean town make you just that full of beans.

In closing this post I ask you Nathan. With 22 patents and who knows how many other fantastic claims to fame. How many folks had given you the where with all to make it where you have? Or maybe to put it in another text. How many great folks did you shaft to get where you are? Jeff N3JBH
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Already paid my 'Union Ham dues' with articles in QST; 73; Communications Quarterly; DX Magazine, among others. First ham article was in 1969. I was 14.

These days my knowledge tends to be targetted towards solving problems tied in with world events. I trust you will excuse me if I pass the ham-writing torch to others.

If I felt there was a way of reaching a ham-only audience without being open source, I wold consider it. For example: if eham went sub only--to hams only.

Don't like that? Too bad bunky!
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
How many great folks did you shaft ...?
--------------------------------------

None. Talent finds it's own level.

But just to give you some insight, being talented; correct; working hard (that is using the talent that's God-given); and having a strong personality make for a dynamic combination!

Luck (more accurately bad luck) is the excuse we give our mistakes.

Or perhaps you came tell us bout some of your own fantstic success?
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
I have a new question for you 'non-resonant' folks.

Exactly what problem are you trying to solve?

Is it REALLY to have a single antenna that works 9 ham bands?

If so, then why do you seek out an antenna that lobes like crazy on 17,15,12, and 10M?

Your antenna, if it is intended to have reasonable electrical length on, say 75m, is going to have multiple current maxima at the higher HF bands, and this will produce substantial 4-leaf clover--and worse--power patterns at the upper bands. There is certainy no scenario where one wants, for example, a figure 8 on 75M and 8-leafed 'clovers' on 10M....


WARN THE newbies!
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Odd choice of words.

----------------------------------------------

C'mon. That's execution as in 'get it done'.

Watch Star Trek and 'execute prime directive'.

Get it?
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
Quit it now chippy, you have shown your true bull crap colors, go lay down by your dish, or better yet go back to your "lab" and create some more patents, everyone has had enough of you now..
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Stop spinnin' yer wheels, OM.
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
"I wager 15 quatloos that he is untrainable"
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Heheh!

Good one:-)
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 30, 2007 Mail this to a friend!
"I wager 15 quatloos that he is untrainable"

"20 quatloos, 100 feet of ladder line, and a homebrew balanced tuner!"

--

google "quatloos" for a hilarious site about dealing with the nigerian scam...

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
WOW i'm totally impressed
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 30, 2007 Mail this to a friend!
"Or perhaps you came tell us bout some of your own fantstic success?"

Sure what ones would you like to know about?

See Nathan you talk of self supremacy. But most of us don’t believe it.
Myself I never admitted to even being educated. Matter fact I have admitted the very lack of it. Yet I to hold only 2 patents but I never bragged about them. All though one of mine is involved in mechanical engineering and the other is ready Chip in the physics field. And with a device that is presently being used by Boeing in Washington.

Again I admit it was luck and just fait that has allowed me to be in the right place and around the right engineers at the right time to been able to have done it. But really struck me as odd was the facts that while your one field of endeavor are an applied physicist.
You never have met Steve Hawking now I realize he is a theoretical physicist instead. And that you never had the wonderful time to hear his lectures. It just amazes me you some how can be so pontificating and condescending on here.

Further more being you have chosen not to embellish us in an open forum.
To increase the better understanding of the plebeians. It only further reinstates the fact your full of beans. See Nathan many of us would be much more receptive of you if you were to assist and educate rather then to belittle them.

But as you have proven here many a times you simply take great joy in blowing large and obnoxious amounts of smoke up your posterior opening of the alimentary canal.

Well I am sure I said plenty here. So to all the good readers of this forum I say good evening, and to you Chippy I say kiss my well you know. I am sure you’ll kiss many more then mine before long.
 
RE: Antenna Lessons from the Old Timers  
by W4SK on May 30, 2007 Mail this to a friend!
Time for that Boston Butt receipe again.
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 30, 2007 Mail this to a friend!
I know where there is some well smoked butt :)
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
OK, now I'm mad and I'm sending my Pirate Llama to kick your ass:

http://www.quatloos.com/images_new/tony-small-gray.jpg
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 30, 2007 Mail this to a friend!
that was too funny :)
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 30, 2007 Mail this to a friend!
He is so good his SWR is ZERO
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 30, 2007 Mail this to a friend!
Looks like this thread has become a personal war between N4SL & W1YW. I thinking...hmmmm a marketing idea... rent a boxing ring and put both of them in it.
15 rounds, get it on HBO or better yet "pay per view"
, bill it as the "Fight of the 21st Century" and I could get RICH!!!

In this corner, wearing the RED trunks, we have N4SL, and in this corner, wearing the BLUE trunks, we have W1YW...get a couple of girls wearing some small bikinis to show the round cards and I think it would FLY! Maybe even get it in Vegas, so all could wager on it, take a small % of the bets...yea!

Wadda yall say? Will give the winner 20% of the proceeds and the loser get 10%.

My paypal acct is: w4lgh@arrl.net start putting your bets in there NOW!!!

73 de W4LGH - ALan
http://www.w4lgh.com


(I'm seeing a YAESU FT-DX-9000D and the BIG StepIr in my future)

 
RE: Antenna Lessons from the Old Timers  
by W7ETA on May 30, 2007 Mail this to a friend!
Well.

Maybe Don will let the eHam experts here turn his article into The Perfect Article--the article he should have written, for beginners, if his ability was upto the experts here on eHam.

Lets see how long it takes, and if any of the resident experts can, indeed, create the The Perfect Article, and one that encompasses everything.

Bob
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 30, 2007 Mail this to a friend!
You are confusing me with the many other people who are posting, there is no war between myself and anyone.

However, I get 20%!
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 30, 2007 Mail this to a friend!
"What's lacking in intelligence here is the ability to read answers already provided."

You have not provided any answers to the scenario I provided.

"And, since you prefer to be with those who ACT like amateurs, N2EY, I have removed myself from your scope of pals. Please honor my request."

What does that mean?

Are you saying I should not challenge what you say?

That I should simply bow to statements like 'never use ladder line' even though you haven't explained why it
should *never* be used?

Are you trying to smoke-screen your way out of the bad
advice you've given, and your lack of practical solutions to real-world problems?

Or are you just telling me to shut up?

"To others: I have been very patient and forthcoming in leading you folks down the path of where the real issue lies--which is the MISMATCH loss, and the impedance of 'non resonants' versus the characteristic impedance of the feedline used."

No, you haven't done that at all, Chip.

"Ladder line is inherently dangerous"

No, it isn't.

"requires extra safety precautions"

So does a ground mounted vertical antenna, or an end-fed wire, or an inverted V, or many other types of amateur radio antenna systems. Those precautions are simple, and can easily be implemented with a little common sense.

"requires an interface to match to the rig ports"

So do many other antenna systems. If a coax-fed antenna system presents an SWR of more than 2:1, most "modern" rigs are going to need a tuner anyway.

"and is not less lossy than good coax"

That depends on what you mean by "good coax". If you're talking about stuff priced less than a dollar per foot, and HF, coax simply loses the loss game. Particularly if operated with significant SWR.

"So there are several reasons why one should never use ladder line."

Not from what I can see. If anything, you have proved the superiority of ladder line.

In fact, I think that's what you are really trying to do. By stating absurdities like "never use ladder line", you're encouraging more and more hams to demonstrate just how good ladder line really is!

Fascinating.

"And, in fact, almost all hams DON'T use it-- and I have yet to see it used in the telecom and wireless arenas. At least in recent generations."

So what? They don't use HF, either.

"For those who do not view this as 'intelligent', then I again invoke the 'CB-morphing syndrome' observation: Classic case of ham radio becoming more and more like the aggressive, nasty, ignorant world of CB, that so many of us 'old timers' find distatsteful and so utterly 'un-ham'."

I'm not just an "old-timer". This year I qualify to be an "old old timer" - 40 years a ham in October. And I say that ladder line is a useful tool in the amateur's antenna-system toolbox. So is coax, for that matter.

But I see what you did there. Call those who disagree with you cbers rather than debate the facts.
 
RE: Antenna Lessons from the Old Timers  
by N6AJR on May 30, 2007 Mail this to a friend!







2 words







FAN DIPOLE






feed it any way you choose, it still works..






nuff said..



tom N6AJR... the Handsome Fellow
 
RE: Antenna Lessons from the Old Timers  
by CDRSLAN on May 30, 2007 Mail this to a friend!
Which type speciffically are you referring too?


73
Ron
kd8fth
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 30, 2007 Mail this to a friend!
Posted By N4SL

AF6AY: "Ya know, I spent some time today looking specifically for ladder-line loss figures. Ya know what, the ONLY thing I found on ladder-line was in a paper that Wes Stewart wrote up, him using a VNA to get those figures. Chip uses a VNA to get his loss figures."

"I even looked for TV twinlead specs and couldn't find any loss figures for that, either."

"Where are all the "expert" tables from MAKERS?""

N4SL: "Len, the ARRL handbook has tables of matched loss vs. frequency for a lot of different transmission lines. It also lets you calculate VSWR loss, which is where the comparisons get much more interesting."

Thanks for the information and your antenna arrangements are interesting. I was specifically looking for manufacturer's data on insertion loss versus frequency for 450 Ohm ladder-line and/or 300 Ohm twinlead. Still haven't found any manufacturer's data on such balanced transmission line products. I have the Times Wire and Cable catalog (extensive data but only on coaxial cable) and some charts from Andrew Corporation for hardline coax (which I don't expect to use/afford). I'm down to only one wrench for SMA connections (used to have two as a 'real' worker in the RF industry, heh heh) but don't expect to use small rigid coaxial cable anytime soon.

I'm not against either open-wire transmission lines or TV twinlead-on-steroids and, if needed, could calculate my own dimensioning for any size wire for any characteristic impedance. Neither am I against the ARRL (I am a member) but they DO tend to get a bit stodgy in their annual Handbooks (I have only their 1978 edition on paper). For a good text on transmission lines in general I use "Theory and Problems of Transmission Lines" by Robert A. Chipman [Schaum's Outline Series], McGraw-Hill Book Company, 1968 [out of print now, mine cost only $4.95 in 1972!], 256 pp large-size softcover. The 165 solved problems are a good guide to use of the basic equations. It does cover HF and VHF applications.

The Chipman book and several inputs from co-workers at RCA Corporation helped formulate some HP-25 and HP-67 calculator programs using a Noise Bridge to find antenna impedance/admittance and to measure the loss and characteristic impedance of coaxial cable over frequency. Ham Radio magazine published that in their May 1978 issue (programs only for the smaller, cheaper HP-25). Worked fine until the homebuilt-and-at-work-calibrated Noise Meter got run over by a Karmann-Ghia (but that's another story). The MFJ-269 antenna analyzer is what I have now (not realizing it does NOT read out the sign of reactance, something I'm not at all happy about after buying it).


N4SL: "For everything else, I use home made open wire line, 600 Ohm, w/ 14AWG 7-strand wire and 3/8" OD spreaders made from gardening irrigation tubing (very UV resistant). My multi-element phased wire arrays are strung out on long ropes hung from tall trees and running real QRO coax (I contest w/ 1500W) to their feedpoints is too heavy, causes too much sag. Especially the 500' long end-fed (33' short stub) zepp at 90' on 80 & 160m, that puppy boosted by Sweepstakes QSOs on 80m by triple."

Good on your contesting. I'm not into amateur radio for contesting or wallpaper collection, I prefer to communicate and experiment with hardware I can pick up without cranes or winches. Neither do I want my residence to look like a radio station; I spent most of 1954 living and working in a two-square-mile former airfield covered with Army wire antennas. MY choice, not my wife's. That means vertical antennas for 6m down to 20m and those fed by buried coaxial cable (inside PVC piping to avoid gnawing by the California Pocket Gopher). For 2m and up a broadband discone works just fine at this northern edge of Los Angeles with backyard 820 feet above mean sea level.

I have a 1/3 acre plot but the flat area plus 2000 square foot house (single story, no basement) leaves just under 1/4 acre. I have two big pine trees in one corner and a row of cypresses on the downhill edge. The cypresses are a bit over 25 feet high in a 105-foot single line but flex too much for stringing; tried that twice for a long wire, worked fine electrically, broke twice due to cypresses NOT swaying together in 30 knot winds. Three jacarandas are tall enough but too flexible for wire antennas...unless there was a low-resistance conductive elastomer available. :-) I'm looking towards a SmallIR or a BiggIR from K4IR's company in Washington state. Radials no problem, downhill neighbor put in metal sprinkler lines rather than PVC and allows me to connect to that for a "radial extension."

Had we decided to keep the northern house (near Burley, WA) I would have been inclined to use balanced line feeder to wire antennas strung over 80 feet high up there. Open-wire transmission lines are lighter in weight than even RG-58 coax. [some of the pines up there over 80 feet high are expected to be harvested, still leaves dozens of mature evergreens] On the other hand, being always older than the FCC, I'd have to hire a tree climber to attach the ends and those aren't cheap. Oddly enough, there's a surfeit of evergreens on the northern property making 100-foot towers/masts a necessity to clear their tops. :-( For me I'd prefer going mobile rather than play radio station up north on that property.


N4SL: "For FD, I have some commercial 450 Ohm 'ladder line' with the insulation and spacer tabs. This works well since it's lightweight, strong, doesn't kink and doesn't get wet in late June. I use RG8-X for coax-fed antennas on FD, seems to be the best price/weight/loss tradeoff."

Since the US Army trained me in Radio Relay, I learned how to erect a 50-foot rotatable mast (with gin pole) for any TRC-1, -3, or -4 antenna. Two guys can do it in less than an hour, including pounding in the four guy-wire stakes. One guy doesn't "walk up" a telescoping 50-foot mast unless they are into weight lifting; that's what the gin pole and small pulley are for. If Field Day were really a "rediness exercise" instead of the Contest it always was, I'd impose a one-hour maximum rule on any ham FD outing-in-the-park complete antenna erection. [we will now hear tales of quick erections - of antennas - during FD, tales which claim all can do it in much less time...:-( ]

"UHF" connectors were in use in military equipment during WW2. Cables for Radio Relay sets had UHF male connectors at each end with "barrels" (female-female) along with tapes in the antenna kit. Unvulcanized rubber tape went over (and past) the joined cables with old "friction tape" (tarry fabric for the youngsters who've only known plastic "electrical tape") over the top of that. It makes a waterproof covering that can be stripped off in a hurry when needed. I've seen where such joinings with tapings have been lying in rooftop puddles for over eight years with no ill effects on VHF performance. Sixty years later the SteppIR, BiggIR, and SmallIR fiberglass protection/support tubes are joined similarly, silicone rubber replacing old black rubber tape, black electrical tape replacing old friction tape.

73, Len AF6AY

 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 30, 2007 Mail this to a friend!
W1YW: "Don't use ladder line. Ever."

N2EY: "Why not? Why take a useful tool out of the toolbox?"

Get a bigger toolbox. So far all you can tool around with are horizontal wire antennas.


N2EY: "Should hams not use BNC or N connectors, since most ham rigs don't have those connectors on them?"

For under about 150 Watts PEP, a BNC, TNC, or N is perfectly fine. The "UHF" connector is CHEAP to make and any patents on it have long since run out. At REAL UHF it is a poor performer.

W1YW: "Take a look at your rig. What is the port?"

N2EY: "My rigs don't have "ports". They do have antenna connections."

The word "port" is common convention in the radio industry for an external connection or at any terminus for a component model of an RF device. Look at S-Parameter descriptions for example.

W1YW: "What does it want to see? Why is there a convention of 50 or 52 ohms for it?"

N2EY: "Because it's easier and cheaper to build a rig to match a single, unbalanced impedance."

Nonsense. Testing, calibrating are commonly done at RF in a "50 Ohm [resistive load and sensor] System" because it is a common convention. RF test equipment is designed around that standard, have been for over six decades.


N2EY: "I'm not stumped on how to make a simple, effective, all-HF-band, single-wire center fed dipole. Or an end-fed wire, for that matter. I think *you* are stumped about how to do it with coax-only feed, but you don't want to admit that ladder line is better for that application.

You can prove me wrong, of course."

Not a problem. Use a simple broadband RF transformer called a "balun." Next question?


N2EY: "I guess we should ban lots of other antennas, too. For example, there can be high voltages on parts of most manufactured HF vertical antennas, so I gues we hams should never, ever use them. And there can be high voltages at the ends of long-wire, dipole and inverted V HF antennas, so we hams should never ever use them either, right?"

Oh dear, trying to be sarcastic are you? Came off like some whiney adolescent. A "not intelligent" whiney adolescent. :-(

Legal radio amateurs just don't have an idea what HIGH POWER RF is like. Try tuning up a FORTY KILOWATT Linear amplifying a 4 KW PEP SSB transmitter. Into 600 Ohm open-wire balanced feedline. On HF with a Rhombic on the other end.

Wanna check the SWR of just the 4 KW SSB transmitter? No problem. Just get two guys with bamboo poles affixed to a fluorescent tube at the ends, walk along the feedline. Eyeball the difference in glow of the light tube. Everyone insulated. No problem. It can even be done in the rain. Did that in 1953 to 1954. Inside the transmitter house NOBODY gets close to those feedlines, okay?

73, Len AF6AY


 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 30, 2007 Mail this to a friend!
W1YW: "I have a new question for you 'non-resonant' folks."

"Exactly what problem are you trying to solve?"

For me: Space. Appearance. Convenience in installation. Getting along with neighbors.

W1YW: "Is it REALLY to have a single antenna that works 9 ham bands?"

No for my part. I'd be content with 20m through '900 MHz' bands. I CAN transmit on 160m to 40m (my IC-746Pro says so into a dummy load) and would accept a "lossy" antenna on those low bands. Base-loading okay, top-hat thingie doesn't "look right" and draws stares.

W1YW: "If so, then why do you seek out an antenna that lobes like crazy on 17,15,12, and 10M?"

I don't know if MY vertical "lobes like crazy." I'll have to hope the manufacturer (of the eventual vertical) specifications are accurate in a reasonable ground-radial system...as advertised. I'd say that either the BiggIR or SmallIR would do as advertised on those 'higher' bands on up to 6m; those adjust length to fit the frequency with the 'higher' bands nominally designed for 3/4-lambda length (can be reset to 1/4 wave through the controller).

Just HOW do you think any amateur radio antenna performance can be plotted in the REAL, PRACTICAL world? I know of one way (that I've been in on) and that is raising and lowering a balloon-borne accurate field sensor at preselected geographical locations (i.e., neighbors' property). That could take two to three months to complete, depending on the bandwidth of the field-strength sensor. I wouldn't care to spend all that time just for some bragging-rights word fight in a newsgroup or on e-ham. Like just about everyone else, I'm stuck with the believability factor in what a maker says their product does.

W1YW: "Your antenna, if it is intended to have reasonable electrical length on, say 75m, is going to have multiple current maxima at the higher HF bands, and this will produce substantial 4-leaf clover--and worse--power patterns at the upper bands. There is certainy no scenario where one wants, for example, a figure 8 on 75M and 8-leafed 'clovers' on 10M.... "

IF AND ONLY IF you are talking about a SINGLE conductor type of antenna, I agree with you. I've played enough with antenna analysis programs to see that.

On the other hand, adding extra lengths with/without traps or reactive components, DOES change both the current and voltage distribution compared to the single-conductor model. That changes the pattern. I won't pretend to intuitively predict WHY it changes but it DOES change the pattern. Certainly on a vertical.

W1YW: "WARN THE newbies!"

Ham radio wise, I'm a "newbie." RADIO wise I'm an "oldie." I will consider myself "warned" if all I can put up for an antenna is single-wire horizontals. So noted.

In the beginning of the 1960s I put a base-loaded short vertical antenna on my '53 Austin-Healey sports car along with a detach mount for a Johnson Viking Messenger CB. I KNOW what the CB had for power output and sensitivity (I measured it in a calibration lab). I got nothing but praise for my signal then, a great help from the aluminum body of the Healey. Probably "inefficient" by some "analysis" and generally laughed at by the "expert" licensed amateurs but it reached out and touched enough folks...including my late first wife. Into the mid-1970s a bunch of us tried to improve the CB in our RCA division manager's Corvette...the one with the fiberglass body. Lots of Reynolds Wrap went into the underside of the trunk but it still couldn't come close to my little Healey's performance with a CB and a shorter whip.

Real Men into DX use Rhombics on four tall poles...with 600 Ohm open-wire line and terminator. :-)

73, Len AF6AY
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Well.

Maybe Don will let the eHam experts here turn his article into The Perfect Article--the article he should have written, for beginners, if his ability was upto the experts here on eHam.

Lets see how long it takes, and if any of the resident experts can, indeed, create the The Perfect Article, and one that encompasses everything.

Bob

-----------------------

The writing is fine. Don writes with the mellifluity of talkin'.

I've made it clear what mods are needed in content.

But for some reason, presumably unrelated, I am reminded of the comment about Asimov (who died of AIDS BTW) that my late literary agent said: "He can take cr*p -- and turn it into real sh*t."

I interpreted that as meaning Asimov had a talent for taking the mundane and making it half interesting, based upon the power of his writing. But one way or another, writing about growing up in a candy store (for example) is limited by the candy store .

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
You never have met Steve Hawking now I realize he is a theoretical physicist instead--N3JBH

---------------------------------
Stop making false assertions.

I met Hawking three times to date. The first was in Boston in 1976. He was talking back then, but barely understandable. For a time I thought of working with him for a year before grad school. I chose to work with Martin Ryle instead, but Cornell insisted I either come to Ithaca or lose my spot. So I went to Ithaca. Damn shame. Wanted to acculturate to Monty Python, and learn interferometry from a ham. A big regret in my life.

My Ph.D. thesis was on gravitational lenses and that qualifies me as a cosmologist. FYI. Among other things.

I got the chance to thank Hawking several years ago for the timing of the release of "A Brief History of Time". My book came out simultaneously, and interest spurred by BHOT rocketed sales of my own book. He gave me a big smile on that one.

Why don't you just shut up while you are behind? Trying to get ahead may lead you into trouble; it is well-known that I don't take highly to defamation.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 30, 2007 Mail this to a friend!
"2 words







FAN DIPOLE
"

Self similar... multiple resonant... hmm. Watch out.

Dan
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 30, 2007 Mail this to a friend!
ok i am finshed. but first i will admit my error and stand to be corrected i have thought wrong on this statement about Prof Hawking. i do now remember that discussion it was in my error. no defamantion was meant about that subject. with that said i will go now. this is getting old fast anyways. Hey big brother glad to see you made it here:)

Jeff N3JBH
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on May 30, 2007 Mail this to a friend!
ok i am finshed. but first i will admit my error and stand to be corrected i have thought wrong on this statement about Prof Hawking. i do now remember that discussion it was in my error. no defamantion was meant about that subject. with that said i will go now. this is getting old fast anyways. Hey big brother glad to see you made it here:)

Jeff N3JBH
 
RE: Antenna Lessons from the Old Timers  
by N6AJR on May 30, 2007 Mail this to a friend!
MISTER CHIP... IT IS EXTREMELY BAD MANNERS TO TEL ONE OF MY FRIENDS TO "SHUT UP"

YOU CONSISTANTLY BEAT ON YOUR OWN CHEST AND TELL US HOW WONDERFULL YOU ARE.


i AM GLAD YOU THINK SO. MY MOTHER WOULD BE EMBARRASED IF I SAID THAT TO ANYONE, SHE TRIED TO RAISE ME WITH SOME MANNERS.

JEFF, I WOULD RATHER SPEND TIME WITH A TRUE GENTLEMAN THAN WITH SOME ONE SO "SUPERIOR.


 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
CB-morphing?
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
Self similar... multiple resonant... hmm. Watch out.

Dan

-------------------------------------

As a pedagogue I admire your quick learning curve.

But no; I'm not going there open-source.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
It's amazing, i searched everywhere, never found one book writen by chippy, still sliging bull crap hey chippy, how much do you want to bet the patents are bullhockey too, give us the patent numbers chippy, lets all see how full of crap you really are
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
It's amazing, i searched everywhere, never found one book writen by chippy, still sliging bull crap hey chippy, how much do you want to bet the patents are bullhockey too, give us the patent numbers chippy, lets all see how full of crap you really are

----------------------------

Give me an incentive. Tell me how you are going to stop embarrassing yourself and apologize for your false characterizations of me, and I will happily give you the info.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
There you go, completely full of crap, no great surprise chippy, the world is full of BULLSHOOTERS just like yourself, now everyone knows it but you
 
RE: Antenna Lessons from the Old Timers  
by K1OU on May 30, 2007 Mail this to a friend!
450 ladder line served me well when I needed it. I'm still alive and have cards to show how effectively my antenna system performed.

Must be a liberal-double-standard-ARRL-kool-aid drinker thing. It's society's fault that I was 40 over 9 on 75.
 
Antenna Lessons from the Old Timers  
by W1YW on May 30, 2007 Mail this to a friend!
There you go, completely full of crap, no great surprise chippy, the world is full of BULLSHOOTERS just like yourself, now everyone knows it but you
-------------------------------------------

OK. let's try it another way. You tell me the last book you read,in toto,with author and year of copyright, and I'll give you the info on one of my books.

One suspects you are not a grammarian...
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 30, 2007 Mail this to a friend!
"Exactly what problem are you trying to solve?"

The problem of limited antenna resources. Not just space to put up an antenna, but supports for it, making it inconspicuous, overall cost, and ease of installation.

Making the most of what's available, really.

"Is it REALLY to have a single antenna that works 9 ham bands?"

That's one *big* reason.

"If so, then why do you seek out an antenna that lobes like crazy on 17,15,12, and 10M?"

Because the alternatives aren't always practical. And because all those lobes that theory predicts are usually not a problem in real life.

Sure, it would be great to have optimized monoband antennas for each HF band of interest. And some hams do just that. But for the rest of us, getting one antenna to do a multitude of jobs is a necessity.

"Your antenna, if it is intended to have reasonable electrical length on, say 75m, is going to have multiple current maxima at the higher HF bands, and this will produce substantial 4-leaf clover--and worse--power patterns at the upper bands."

So what?

"There is certainy no scenario where one wants, for example, a figure 8 on 75M and 8-leafed 'clovers' on 10M...."

Sure there is. And in real life, it usually doesn't work out that way anyhow. Proximity to the ground and other conductors messes up those deep nulls.

Any simple multiband antenna is going to be a compromise. The question is, what's the best possible compromise? If all HF amateur bands are to be covered, it sure isn't a single dipole center-fed with ohm coax!

But feed the same antenna with ladder line and a good balanced tuner, and the results are much better.

Here's a challenge for the experts:

Do some calculations of an 80 meter dipole at 50 feet with 100 feet of transmission line. Figure out the transmission line loss on each HF amateur band when using, say, RG-213. Then recalculate using good-quality ladder line.

Antenna modeling software makes this easy. The results are pretty clear.

If you *really* want to see the difference, repeat the calculations with 200 feet of transmission line.

Then tell me why hams should never use ladder line.

 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 30, 2007 Mail this to a friend!
You keep on ducking and diving just like you did with antenna farm question, we ALL can see through your bull, nothing but a big bag of wind, but i guess you'll have that in bean town
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 30, 2007 Mail this to a friend!
"As a pedagogue I admire your quick learning curve. "

As a pedagogue, you might appreciate that few people can learn when faced with a confrontational style.

Due to your long and storied history of internet forum discourse, you may appreciate that I didn't figure out that fan dipole thing just now, but thought I'd wait for someone else to mention it, just to make a point.

As a stalwart advocate of the advancement of Part 97 goals, you may appreciate the reproduction of the "fundamental purpose" of the amateur service right here, as taken from

http://www.arrl.org/FandES/field/regulations/news/part97/

- - - - - -

The rules and regulations in this Part are designed to provide an amateur radio service having a fundamental purpose as expressed in the following principles:

(a) Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.

(b) Continuation and extension of the amateur's proven ability to contribute to the advancement of the radio art.

(c) Encouragement and improvement of the amateur service through rules which provide for advancing skills in both the communications and technical phases of the art.

(d) Expansion of the existing reservoir within the amateur radio service of trained operators, technicians, and electronics experts.

(e) Continuation and extension of the amateur's unique ability to enhance international goodwill.

- - - - - -

Part (a) if it says anything technical at all, requires a good frequency agile station capable of effective communication. Doesn't really matter what sort. Reliability, operator expertise in use of said station, and ease of ad-hoc repair and construction might be important here. Innovation is not.

Part (b) ... advancement of the radio art. While novel antenna impedance matching techniques and antenna widebanding certainly advance the radio art, I think it would be reading too much into this vaguely worded principle to suggest that this, in particular, was wholly the intent of the inclusion of this statement. Think, in particular, of those developing signal processing techniques who care very little about the particular transducers in between the D/A and A/D converters on each end of the circuit, and yet rely on those transducers and those using them to make progress.

Part (c) ... advancing skills in both communications and technical phases of the art. The FCC is grading us, if you will, on effort and improvement of our own personal skill set, not, in particular, on individuals who leap ahead of the pack. They have value, for sure, but are not the sole focus of this purpose.

Part (d)... trained operators and technicians, and electronics experts.

To be locally fashionable though perhaps a bit unconvincing, I will quote the Wikipedia definition of "technician" here: "A technician is generally someone in a technological field who has a relatively practical understanding of the general theoretical principles of that field..." Neither technicians nor operators are *necessarily* electronics experts, yet the FCC finds all three to be valuable. Consider, in particular,

Part (e) also requires an effective antenna of no particular description.

- - - - - -

A non sequitur at this stage, maybe, but I thought I'd bow out after this post, allowing everyone to contemplate the role of significant antenna innovation within the overall purpose of ham radio. I felt it needed a different spin put on it...

Maybe those of us using old creaky technologies for emergency communication and just chewin' the rag all friendly-like with the DX aren't so far from the purpose of Part 97 after all.

73,
Dan














Dan
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 30, 2007 Mail this to a friend!
The second Dan came in on the long path.
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 30, 2007 Mail this to a friend!
W1YW: "What's lacking in intelligence here is the ability to read answers already provided."

N2EY: "You have not provided any answers to the scenario I provided."

'You' wrote the article? I think not. Don Keith did. Why must anyone answer YOUR 'scenarios?'

W1YW: "And, since you prefer to be with those who ACT like amateurs, N2EY, I have removed myself from your scope of pals. Please honor my request."

N2EY: "What does that mean?"

One word: Disassociation. [with yourself]

N2EY: "Are you trying to smoke-screen your way out of the bad
advice you've given, and your lack of practical solutions to real-world problems?"

No, Chip isn't but you are...

N2EY: "Or are you just telling me to shut up?"

Tsk, only God can make you shut up...:-)

W1YW: "To others: I have been very patient and forthcoming in leading you folks down the path of where the real issue lies--which is the MISMATCH loss, and the impedance of 'non resonants' versus the characteristic impedance of the feedline used."

N2EY: "No, you haven't done that at all, Chip."

Yes he has. You've been refusing to accept the truth.

W1YW: "Ladder line is inherently dangerous"

N2EY: "No, it isn't."

Well, if it ISN'T "inherently dangerous" (which I don't accept absolutely, either, BTW), then it must be 'inherently safe.' I can't find any affirmation of that 'inherently safe' supposition of yours anwhere in the cantu-respondu of this article. <shrug>


W1YW: "requires an interface to match to the rig ports"

N2EY: "So do many other antenna systems.

Hello? WHO was doing all the talking about lengths of transmission line and matching (making resistive at the proper value at transmitter end)? It was either N2EY or an imposter using your call.

N2EY: "If a coax-fed antenna system presents an SWR of more than 2:1, most "modern" rigs are going to need a tuner anyway."

My IC-746Pro doesn't. :-)

W1YW: "and is not less lossy than good coax"

N2EY: "That depends on what you mean by "good coax". If you're talking about stuff priced less than a dollar per foot, and HF, coax simply loses the loss game. Particularly if operated with significant SWR."

Tsk, at 40m (low end, your apparent favorite band) the loss per hundred feet is less than a half db. Since there don't appear to be any loss specifications from manufacturers of ladder-line, the point is moot. Ah, but Wes Stewart wrote a nice paper and stated one figure based on VNA measurements he made. Have you done any such VNA measurements on your ladder-line?

W1YW: "So there are several reasons why one should never use ladder line."

N2EY: "Not from what I can see. If anything, you have proved the superiority of ladder line."

Tsk, tsk. Chip has explained his reasoning. You have refused to acknowledge such reasoning exists. Are they working you too hard at Consolidated Rail Corporation or what?


W1YW: "And, in fact, almost all hams DON'T use it-- and I have yet to see it used in the telecom and wireless arenas. At least in recent generations."

N2EY: So what? They don't use HF, either.

You are WRONG about HF. The maritime world still uses HF. The international civil aviation community still uses HF. The US government still uses HF (see some examples from SHARES). Obviously the "SW BC" community uses HF. The US military still uses HF (but not nearly so much as it used to).

I've seen lots of pleasure boats with equipment using HF but haven't seen one without coaxial cable going to the antenna. No doubt there may be some larger water vessels balanced line to their antennas but I don't recall any amongst all those that either use coaxial cable or a SINGLE WIRE going to the HF antenna. I've never seen any aircraft using balanced line feed to an HF antenna, some of the very old ones used a SINGLE WIRE (definitely unblanaced) "feedline." Maybe some of the broadcast stations on HF use balanced line antenna feed? Those that are left run power outputs rather greater than 2 KW so those techniques wouldn't apply to amateur use. In the main, the US government and military HF transmitters have transmitters with under 1 KW RF peak anything and use coaxial cable feedlines.

W1YW: "For those who do not view this as 'intelligent', then I again invoke the 'CB-morphing syndrome' observation: Classic case of ham radio becoming more and more like the aggressive, nasty, ignorant world of CB, that so many of us 'old timers' find distatsteful and so utterly 'un-ham'."

N2EY: "I'm not just an "old-timer". This year I qualify to be an "old old timer" - 40 years a ham in October."

What would you like for an anniversary present? A cane or a walker? Must be a walker since those are inherently "balanced," canes are one-sided, therefore inherently unbalanced. :-)

Do you have your reservation made at the Olde Hammes Home? Better hurry, times a'wastin...

N2EY: "But I see what you did there. Call those who disagree with you cbers rather than debate the facts."

We can all see what you've done in here...pout because someone talked against your "expertise."

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by KE3WD on May 30, 2007 Mail this to a friend!
I'd say something but I've gotta run outside and light my cigar off the open ladderline while the Henry's keyed up.

.
 
Antenna Lessons from the Old Timers  
by N6VL on May 30, 2007 Mail this to a friend!
I have seen some misinformation in the replies.

Reflected power does NOT cause RF in the shack. Having a voltage point on the feedline will cause RF in the shack.

Reflected power does NOT dissapate in heat with good ladder line. That is true with coax, but not good ladder line.

LB Cebik, W4RNL, a respected antenna expert loves open wire line. He also loves truly balanced tuners, not the ones with a balun on the output.

I use a favorite of Cebik's, the 44 foot dipole. It is fed with ladder line and a has broadside gain on the bands above resonance. On 10 meters, it is 2 5/8 waves in phase. Above 30 MHz, the pattern starts to degenerate into little lobes.

I use a different antenna for lower HF bands, a delta loop, also fed with ladder line. Don't try to cover the entire HF spectrum with one antenna if possible.

Guess what! I have no RF floating around the shack with either antenna. I put some effort into routing the feedlines into into the house and keeping it balanced.

I generally agree with the author. The only exception would be using the antenna at a frequency greater 2.5 times its fundamental resonant frequency. The pattern breaks up into funny little lobes.

73,

Steve N6VL
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
As a pedagogue, you might appreciate that few people can learn when faced with a confrontational style.

----------------------------------------

Where the heck have YOU been? Not at any US University, if that's the case.
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
You know, I STILL am hearing this myth about ladder line being superior to coax because of loss issues.

Many say it, but no one seems to be able to justify it.

I will make your path oh so much easier; after all, it is a shame not to learn something from such an investment of good debating.

SO, here it is.

Coax is locked into a set of possible chracteristic impedances, the highest easily, commercially, available being 93 ohms. Ladder line, with little exception, is a 'roll your own' product and thus one can fabricate LL with virtually any characteristic impedance. Get it? YOU can CHOOSE what impedance you want for your ladder line (with some exceptions; in any case you can vary it far more than the coax option).

Now: I ask again--WHAT PROBLEM ARE YOU TRYING TO SOLVE? The 'advantage' of this non-resonant antenna is it is a single wire that works on many, many ham bands. HOWEVER, the impedence at the feedpoint varies widely. SO... looking at this as AN OPTIMIZATION PROBLEM, where you are trying to DEMONSTRATE the superiority of LL from a MISMATCH LOSS standpoint...

**WHAT IS THE CHARACTERISTIC IMPEDANCE OF LL THAT BEST MEETS THIS NEED? **

Don't guess; don't play with past myths--TELL US WHAT **VALUE** of LL impedance works for the antenna discussed here; how you arrived at it, and why.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
Reflected power does NOT dissapate in heat with good ladder line. That is true with coax, but not good ladder line
---------------------------------

Where DOES it 'dissapate' and in what form? Mechanical? Sonic? What?
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
I'd say something but I've gotta run outside and light my cigar off the open ladderline while the Henry's keyed up.

----------------------------------------------

That would be an amazing feat, because MY Henry 2K-D Classic has NO LL ports, and requires 52 ohms. Coax. What's special about yours?
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
Looks like this thread has become a personal war between N4SL & W1YW.
---------------------------

Not at all. I LIKE what N4SL has done. He's worked hard to get a particular variety of antennas to work for him. My point is that if we understood the problem we could get other ansnwers.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 31, 2007 Mail this to a friend!
When I was a kid I bought an old roll of ex-War Department coax. My Mom was very supportive of ham radio because it was less expensive than girls. One day she phoned my shack and said, 'Gil there's a puff of steam blowing out of your new coax'.
 
RE: Antenna Lessons from the Old Timers  
by CDRSLAN on May 31, 2007 Mail this to a friend!
I being new to the forums(reading since March 2007) am amazed at Chips advice. Honest questions are attacked. That tells me Chip is a BULLSHOOTER. Also, one who has "passed the torch" because he is so involved with world affairs spends a lot of time arguing with us ignorant cb'ers. Why Chip should be reasoning with foreign governments to sure-up foreign relations.

Ron
kd8fth
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
When I was a kid I bought an old roll of ex-War Department coax. My Mom was very supportive of ham radio because it was less expensive than girls. One day she phoned my shack and said, 'Gil there's a puff of steam blowing out of your new coax'.
=============================================
Hence a real-life story that confirms the adage: 'don't buy crap coax'.

Also, if you couldn't afford good coax, how did you afford a separate phone system, presumably one just for your shack?
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
That tells me Chip is a BULLSHOOTER.

-=----------------------------------------

Nope. Never shot a bull. But I have a sharpshooter rating. Too bad my eyes are going.

You should see my son though. He can take down a crow at 300 yards with a 22.

Not in Massachusetts, of course.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
As a pedagogue, you might appreciate that few people can learn when faced with a confrontational style.

-----------------------------------------------------

...and obviously you haven't been in the military. They'll kick yer a## --to help you help save yer own life and those of yer buds.
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
On the other hand, adding extra lengths with/without traps or reactive components, DOES change both the current and voltage distribution compared to the single-conductor model. That changes the pattern. I won't pretend to intuitively predict WHY it changes but it DOES change the pattern.

----------------------------------------

This is true. Nulls are actually pretty sensitive to small changes in the geometry or electrical length of the antenna. Many of those deep nulls can be made into moderate 'dimples' instead.

Good point.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by KE3WD on May 31, 2007 Mail this to a friend!
"You should see my son though. He can take down a crow at 300 yards with a 22."


Right.


Look, this isn't hardcore physics.

Assuming you mean the ubiquitous .22 long rifle round, I call BS.

At 300 yds, your son would have to hold so high he couldn't see the crow for the barrel if using iron sights and the field of view of a scope, the crow itself would be so far below as to make it more so.

This is a subject that I know about from empirical work over decades of time.

I have "dinged" the metal silhouette target at 200 meters fairly consistently with extremely accurized .22 rifle (drop is about four feet, target is about 18 inches). C.S. Landis wrote about
killing a woodchuck at 175 yards with a .22 but considered that a lucky kill.

For practical humane hunting and varmint control using a .22 rifle and iron sights, 50 to 75 yards should be considered max. Add a scope and the true sportsman can extend that out to about 100 to 125 yards with practice, most of the time that would be a shot I would NOT take. But I have concern for the crow.

Anyone carrying on about SAFETY of ladderline in all caps yet making a bizarre statement like this about firearms and hunting will never be allowed to handle firearms around this writer.

At four hundred yards, a .22 long rifle will not penetrate a common galvanized steel bucket (but it could still put your eye out kid).

The old warning on the boxes of .22 long rifle ammo that proclaimed that the round could travel 1 mile may be true, but made no claims as to accuracy, not to mention bullet velocity or the lack thereof. Gravity. One mile would be one helluva drop shot from the top of a hill.

Chris, intelligence and academic ability are one thing, a psychosis can happen to anyone. Please be careful, maybe find someone to talk to about yourself, we need you hittin' on all eight.

No offense intended. Just concern.


.
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 31, 2007 Mail this to a friend!
N6VL says..."Reflected power does NOT cause RF in the shack. Having a voltage point on the feedline will cause RF in the shack. Reflected power does NOT dissapate in heat with good ladder line. That is true with coax, but not good ladder line."

Reflected power does cause RF hot spots along the feed line, therefore it can cause RF in the shack! I have also seen these "rf hot spots" burn the feedline in half, so again, it does go up in heat!

As I have said many times, if you use ladder line as your feed, it has to be hooked to a tuner, or some other matching device in your shack. With this type of hookup your "Antenna System" starts in the shack at the matching device. When using coax, your "Antenna System" starts at the antenna feed point, where the coax terminates. Again, this is what COAX was invented for. Ever look inside your new radio? Notice there is all kinds of little coax cables connecting different board together? Wonder why they didn't use ladder line to connect these? Could it be they didn't want any RF leakage? They wanted the board to look electrically connected as one? Shielded cable (coax) was developed to move your "Antenna System" away from your transmitter, just like waveguide on microwave. Just the simple idea of it being "SHIELDED" implies this. I have no idea why anyone wants to argue about this, but its just plain fact.

If you want to be able to tune your antenna from the shack, and NOT use an auto-tuner at the antenna, then you have to use open ladder line to do so. If you want to move your antenna system away from your shack, then you use good quality low loss coax, and either install an auto-tuner at the antenna, use a resonant antenna for one frequency, or use a multi-band antenna that is resonant on different bands.

Losses due occur in tuners, feed lines and antennas. These losses are radiated as HEAT, if great enough, will burn thru or across. Tuners arc over and burn, as do feed lines. This is why each piece in your antenna system is rated for a MAXIMUM amount of power. These power level can increase if mis-matches exsist. No antenna is perfect, they are all a big compromise at best. Use what works for you.

73 de W4LGH - Alan
http://www.w4lgh.com

 
RE: Antenna Lessons from the Old Timers  
by W0IVJ on May 31, 2007 Mail this to a friend!
Chip, W1YW,

Are you usng any fractal antennas on HF? If so, could you share with us some of the specifications and performance characteristics with out giving up an proprietory information?

Thanks and 73,

Tom W0IVJ
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 31, 2007 Mail this to a friend!
Everyone is so tense, let me show you a picture taken (of me) at the last Field Day:

http://i74.photobucket.com/albums/i256/lololeaf/ManBoobsII.jpg

Now, some alcohol was involved.
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
Chip, W1YW,

Are you usng any fractal antennas on HF? If so, could you share with us some of the specifications and performance characteristics with out giving up an proprietory information?

Thanks and 73,

Tom W0IVJ
-----------------------------------

Hi Tom,

Yes I am;

And no Tom; I won't. Although I did publish in many places, including ham magazines, a decade ago, I will not publish open-source info on such antennas. Sorry. I know that must be disappointing.

If ham radio had well-viewed ham-only sites I would definitely consider it. As it stands, I'd like a bit of say on where they end up.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
At 300 yds, your son would have to hold so high he couldn't see the crow for the barrel if using iron sights and the field of view of a scope, the crow itself would be so far below as to make it more so.

-------------------------------
He wasn't using a 'barrel' or shooting at one. He was using an iron site into a covy(?) of crows. He shot from the farmhouse down into gently sloping cornfield and aimed high. He has his granddad advising him on how to do the shot. Damned if he didn't pull it off.

You are certainly correct that individual sparrows at 200 feet are more tempting, especially if they are eating up the garden seed. He's pulled that off many times. Cats were thrilled.

Now getting a turkey in the head--THERE'S a challenge!

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 31, 2007 Mail this to a friend!
"He wasn't using a 'barrel' or shooting at one. He was using an iron site into a covy(?) of crows."

HOLY CATS! HAHAHAHAHAHA!!!!!
O.M.G. :)
Were they out of real guns when you trained in the Army or what?!?
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
Uhhh... one hopes that really NOT your FD picture... any perticular reason why you led us to this, well, monstrosity? Is their ladder line on the tattoo?
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 31, 2007 Mail this to a friend!
Yeah, I kinda hate that picture because I finally stopped smoking and it reminds me of when I did.

Those aren't tattoos, they are RF burns from Ladder Line.
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 31, 2007 Mail this to a friend!
In fact, I feel cheated because I was born too late to be Clark Kent's stand-in.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on May 31, 2007 Mail this to a friend!
"And no Tom; I won't. Although I did publish in many places, including ham magazines, a decade ago, I will not publish open-source info on such antennas. Sorry. I know that must be disappointing."

I remember the fractal 10m quad... cool antenna.

But this is really what it comes down to. We do not have access to the antenna design capabilities you have, Chip. We would have to independently enter into competition with you to have them, or at least spend a lot of time independently hacking through the engineering of fractal antennas for our own consumption. I do remember that it was somewhat dangerous to mention any attempts to do so at some time in the past.

Some of us may feel that it's an interesting problem to tackle to come up with antennas with similar desirable characteristics in an independent fashion. Some of us may want to independently develop an algorithm to design an antenna with these characteristics. (Here I'm talking about broad or multi-band 50 ohm resonant and a tame single-lobed radiation pattern, just to take a simple, favored counter-antenna to the open wire fed doublet).

You could imagine (forgive any similarity to a trademark, if you will, Chip) a FANDAGO program... fan dipole antenna genetic optimizer, that designed your 9 band 50 ohm direct feed fan dipole for you and even was clever enough to discard overly fussy antennas in terms of construction tolerances (not a whole lot of backyard HF antennas being photoresist etched on Duroid microwave board, eh?)

Spend a few years developing and testing it. Open source it to the community so that hams can benefit from your work. Now all you need to do is get hams to string the mess up in the backyard ... and find out that you need to spend another four months adding "tree and car" input into the optimizer because no one can actually build the thing.

Sort of a lot of work to satisfy the particular artificial requirement that a 9 band HF antenna be direct coaxial feed and single-lobed.

You could do it... but why? The only reason I can see to do it is because you really NEED to meet those requirements, either for technical or emotional reasons.

There are so many ways one can arrange a certain set of electrical conductors in one's backyard to form an effective set of electromagnetic transducers for the nine HF ham bands and the five 5MHz channels. Novel ones are of interest to some folks, but others prefer tried-and-true, and that's not inconsistent with the Part 97 mission.

Dan



















 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 31, 2007 Mail this to a friend!
Tell us another story chippy, pah leez, you should be writing for disney, aaa hhaa,, maybe thats where i'll find the book's you wrote, your still the best bullshi##er on this site
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on May 31, 2007 Mail this to a friend!
Well...I will tell you of one super working antenna that I would have never believed in 100years. I installed a Yaesu FT-857D in my SUV, and while in Dayton, I ran into a ham buddy from my home city. He gave me a brand new ATAS-120A screwdriver antenna also made by Yaesu, so the radio will auto-tune it, and the performance is completely un-believable! For an antenna of that size to work like it does! Now wonder if it would be better feeding it with super low loss ladder line, instead of that tiny RG-316 coax? I guess I could get a couple of 4:1 baluns, and cut a board to fit my window, so I could get the ladder line out of the suv to the antenna. But then I wonder if the baluns will pass the DC to tune the antenna?? Think I will leave well enough alone.

Seriously tho...it is a SUPER mobile setup. I never would have thought it would work like it does.

73 de W4LGH - ALan
http://www.w4lgh.com
 
RE: Antenna Lessons from the Old Timers  
by N2EY on May 31, 2007 Mail this to a friend!
Well, there's been a lot of words posted here, but not many numbers.

I posted a realistic antenna scenario a couple of times, but none of the experts/professionals were up to the challenge, other than to say "use coax feed" or some such.

So I did some figuring on my own.

In the scenario I described, an amateur's residence made it practical to string a center-fed single-wire dipole between two trees.

This antenna was chosen because it is mechanically simple and rugged, inexpensive, easy to build, doesn't require special materials or tools to build, and is tolerant of minor variations in construction. IOW, it's easily realizable.

After all, amateur radio antenna design is more than 90% mechanical engineering and less than 10% electrical engineering.

I used two software packages:

G4FGQ's DIPOLE3, available at:

http://www.btinternet.com/~g4fgq.regp/page3.html#S301"

was used to find the feedpoint impedance and load SWR for each frequency that was evaluated.

and

http://www.ocarc.ca/coax.htm

was then used to compute the losses in the transmission lines.

To put some numbers on thus antenna, it's a 127 foot long single-wire center-fed dipole, 50 feet above average ground, made of #12 copper wire. At that height, it's half-wave resonant at 3.75 MHz.

The transmission lines evaluated were:

100 feet of Belden 8237

and

100 feet of generic 600 ohm ladder line

The results are shown below, in the following format:

Frequency - Feed Z - Coax SWR/loss - LL SWR/loss

3.750 MHz - 70.3 + j0 - 1.4/0.353dB - 8.5/0.157dB
3.500 MHz - 59.4 - j126 - 6.9/1.023dB - 10.5/0.186dB
4.000 MHz - 82.4 + j122 - 6.0/0.968dB - 7.6/0.146dB

7.150 MHz - 2865 + j3053 -124/8.858dB - 10.3/0.26dB

10.125 MHz - 137 - j656 - 61/6.944dB - 9.7/0.291dB

14.175 MHz - 947 + j1601 - 74/8.267dB - 6.6/0.24dB

18.118 MHz - 144 - j481 - 34/6.018dB - 6.9/0.282dB

21.225 MHz - 485 + j953 - 48/7.478dB - 5.0/0.228dB

24.940 MHz - 376 - j987 - 57/8.417dB - 6.4/0.309dB

28.880 MHz - 478 + j848 - 40/7.423dB - 4.3/0.233dB

On 80/75 meters, there is little difference (less than a decibel) between the two transmission lines.

But look at the other bands! The worst-case ladder line loss is less than a third of a dB, while the *best*-case coax loss is a bit more than 6 dB. Worst-case coax loss is more than 8 dB.

Tuner loss? With either line, a tuner will be needed, except for a small part of 75 meters near the resonant point. Of course the tuner may be an ATU built into the rig, but it's still a tuner, and being built into the rig doesn't make it lower loss.

Seems pretty clear to me that this is a scenario where ladder line is clearly superior.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by K5ML on May 31, 2007 Mail this to a friend!
Let's step back a minute and think about all the stuff posted above. We have a Ph.D. scientist who claims to have associated with the likes of Steven Hawking and performed remarkable scientific feats. He also tells us that he is in his early fifites. Assuming that is all true, he is still a relatively young man and in the peak earning/productivity years of his professional career. Yet, he spends copius amounts of time arguing with a few hams about the evils of ladder line? I'm no scientist or mathematician, but this just doesn't compute.

73,
Mick, K5ML
 
RE: Antenna Lessons from the Old Timers  
by N9FE on May 31, 2007 Mail this to a friend!
Yes ladder line is the winner by far, and the best part is when you turn the dial on the matchbox and the tvi "with rabbit ears" completely disapears, the reflected power drops to absolutely nothing, then you hear a s2 station and call him and he tells you your 20 over s9 are you running power, you tell the TRUTH no 100 watts, happens everyday, this never ever happened with a coax fed dipole, never,
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 31, 2007 Mail this to a friend!
W1YW: "You should see my son though. He can take down a crow at 300 yards with a 22."

KE3WD: "Right. Look, this isn't hardcore physics. Assuming you mean the ubiquitous .22 long rifle

round, I call BS."

Look, this is a forum about ANTENNAS, not marksmanship.

KE3WD: "At 300 yds, your son would have to hold so high he couldn't see the crow for the barrel if using

iron sights and the field of view of a scope, the crow itself would be so far below as to make it more so."

I've been in the company of several Old Crows and shooting never came up...even if the Association of

Old Crows is a professional group of Electronic WARFARE specialists. <shrug>

KE3WD: "This is a subject that I know about from empirical work over decades of time."

Ahem...the general subject of this article is ANTENNAS. For radio. Amateur radio.

If you have to shoot something, I'd suggest talking to some CB-ers who "shoot skip," not Chip. :-(

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 31, 2007 Mail this to a friend!
AF6AY: "On the other hand, adding extra lengths with/without traps or reactive components, DOES change both the current and voltage distribution compared to the single-conductor model. That changes the pattern. I won't pretend to intuitively predict WHY it changes but it DOES change the pattern."

W1YW: "This is true. Nulls are actually pretty sensitive to small changes in the geometry or electrical length of the antenna. Many of those deep nulls can be made into moderate 'dimples' instead.

Good point."

Thank you for that. I was leading into a general subject of antennas for newbies who are looking to get on the air with the lesser amount of physical work, not concentrating on the "Battle of the Line" which seems to be the mode in here. :-(

Wire horizontal dipole: Okay in itself, bidirectional, but NOT omnidirectional. Newbies don't necessarily know exactly the direction they want to "work stations." That wire horizontal dipole needs SUPPORTS for the ends. "Experts" tend to blow that off with statements like "everyone has at least two trees in their back yard" or "just use a mast/small tower" or "attach one end to the side of the house."

Contrary to popular opinion, everyone does NOT have enough trees on their property that are in just the right position and with enough height. Trees take a long time growing but they DO continue growing; the distances between attachment points will change over time. Failure to account for that change will result in either sagging or tensioning to the point of snapping the whole horizontal dipole. Climbing a tree may be okay to some teen-ager with agility but it can also be dangerous for that same teen-ager or an adult, with or without a ladder to help getting up the first 15 feet or so without branches.

Using masts of thin-wall conduit is fine up to roughly 30 feet. Beyond about that there is a great problem in keeping the mast/conduit from bending during raising. There's a cure for that but I've never seen it in the ham antenna books. Seldom is the "gin pole" mentioned or how to use it properly. Seldom is there a good description of ground-stake insertion/fastening. All residences don't come with nice, consistent soil that allows hammering-in guy stakes or their holding power. Neither is the force of winds or stress on guys or some simple trigonometry to approximately pre-measure guy lengths.

Attaching one end of a horizontal dipole or sloper to the house sounds easy enough...until one has to do it. Nobody warns to pull-test an attaching eye or hook first before erecting that dipole wonder antenna. In fact, brick and stucco exterior wall residences have very few locations to install eyes or hooks designed for wood. [I've seen where someone actually pulled off a siding overlap board and had to renail a long piece of it...only to repeat the whole thing] Then too is how high up an attachment point is and whether or not an extension ladder has to be used; not every home owner has one; one can rent power machinery okay but simple extension ladders almost have to be bought.

The apartment dweller is almost SOL for putting up a horizontal dipole. End-fed Zepp maybe. Depends on the landlord. Whatever residence location there is the fact of having to work at height and possibility of falling.

Vertical monopoles: Lots of those multiband types for sale, ready to assemble. Take only one central spot on a flat lawn plus whatever guy stake locations are needed. Disadvantage is having to install "enough" radials for the "earth image" to simulate ground. A rented lawn edger (in not available in garden/yard maintenance tool set) will make quick work of shallow trenching sufficient to lay in #14 or #12 insulated electrical wire as radials, then cover it. Antenna books are rather unspecific on how deep a trench needs to be, or that insulated THHN electrical wire will do the job just fine and is relatively cheap. Neither do the antenna books say anything about sprinkler piping influence if metal pipe was used; PVC pipe for sprinklers has no noticeable effect.

A shovel and elbow grease handles digging a mounting pit for a vertical. A simple Level from a hardware store will tell you when a temporary support has the ground mounting pole vertical. Concrete mix of many kinds is available from do-it-yourself stores, just add water, stir and pour. Need to connect the radials? Not a problem. Get perforated galvanized metal plumber's tape, solders easily, has enough perforation holes for 30+ radials if wound into a 1 to 1 1/2 foot diameter ring, same stuff can connect to the ground mounting pole. Or just skin some THHN solid electrical wire and form that into a circle, solders to even better. Or spend a lot of money for a very nice-looking stainless steel DX Engineering radial connect plate and then cover it all up with dirt when finished.

An inherent safety feature of putting up a vertical is that NO ladder or tree climbing need be done. One always stands on the ground. At roughly 25 pounds for a 25-foot vertical multiband, one ham can raise it and mount it once a level ground support pole is cured firm and at true vertical. The same is true for horizontal dipole end masts...although two people are usually best, one at each end support mast.

Copper repiping of residences has been going on for at least two decades. Copper pipe makes a wonderful ground plane, especially so for a one-story, no-basement house. Antenna books don't say much about that. Neither do the books mention either metal electrical wire conduit or the wire itself (if Romex or equal) and its effect on antenna patterns. They don't say anything about seamless aluminum guttering or downspouts, structure components that would be closest to external antennas.

In general, I'd say that the antenna books do NOT cover enough of the OTHER tasks needed to put up antennas besides wire lengths and regurgitated old graphics reprints. Those OTHER things are every bit as essential as the wire to the antenna system. For a newbie, I'd say the easiest HF antenna to install is a vertical. They can do it all by themselves (newbies won't have old, established ham buddies to help, as a rule). A horizontal antenna of just wire is the cheapest, of course, but only if one doesn't count the antenna tuner needed to work multiband. A horizontal antenna takes more physical effort to install. The vertical antenna is roughly omnidirectional at all frequencies while the horizontal antenna is roughly bidirectional but the pattern can be much different on frequencies above its 'resonance.'

Just a few things that apply in the real world, not in the fantasy realm of every ham a DX champion by using some magic feedline...

73, Len AF6AY

 
RE: Antenna Lessons from the Old Timers  
by KE3WD on May 31, 2007 Mail this to a friend!
When we are discussing antennas and someone else comes up with talk of shooting, don't get all over my case for showing them how full of crap they really are.

Especially when that certain someone then states this:

"He wasn't using a 'barrel' or shooting at one. He was using an iron site into a covy(?) of crows."


All of my firearms have barrels on them.

I've never met a real shooter who would make a claim of a 300 yd. shot and then change that to shooting into a group of targets after being busted for BS. Keywords: "Real Shooter".


Of course, my main wire antenna is fed with ladderline and now we've all been told repeatedly that we should "never use ladderline".

FOR ALL CAPS REASONS OF SAFETY!

Some guys appoint themselves as experts, others as forum police.

I just have fun with the hobby.


.
 
RE: Antenna Lessons from the Old Timers  
by N4SL on May 31, 2007 Mail this to a friend!
I found the book "HF Antennas for All Locations" by Les Moxon to be interesting, he goes into some details of alternative antennas, methods of getting it into the air and especially for smaller lots. ISBN #1 872309 15 1

Me? I can in fact hit a crow at 300 yards but I know I've got to use my 700PSS .308 and handloaded ammo to do so.
Sierra MatchKing 168gr HPBT, turned Lapua brass, Federal Match primers and 45.6gr of Varget with an OAL of 2.824" does the trick for me. BS? Nope.
 
Antenna Lessons from the Old Timers  
by W1YW on May 31, 2007 Mail this to a friend!
There are so many ways one can arrange a certain set of electrical conductors in one's backyard to form an effective set of electromagnetic transducers for the nine HF ham bands and the five 5MHz channels. Novel ones are of interest to some folks, but others prefer tried-and-true, and that's not inconsistent with the Part 97 mission.

Dan

---------------------------

The state of the art in antennas is not being done by hams as hams. Accept it.

Maybe those old 'crows' have something to do with it (some may need to pay their dues--as in money). But, then again, either I compute or don't. And why should I personally care which of the 2 that K5ML accepts as factual?

BTW, he did a fairly reasonable job of re-stating the facts. Of course, since he doesn't (apparently)know anyone who's paid those dues IMO, he can't imagine that anyone who sacrificed; work harded; pushed through disappointment and failure;nd pushed themselves to get there really exists. And still have the Fall of life to look ahead to.

Too bad.

Of course, that's nothing compared to one day of the life of an American soldier or Jarhead these days. They are my damn heroes.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on May 31, 2007 Mail this to a friend!
N2EY wrote:
"Well, there's been a lot of words posted here, but not many numbers."

"I posted a realistic antenna scenario a couple of times, but none of the experts/professionals were up to the challenge, other than to say "use coax feed" or some such."

"So I did some figuring on my own."

"In the scenario I described, an amateur's residence made it practical to string a center-fed single-wire
dipole between two trees."

"This antenna was chosen because it is mechanically simple and rugged, inexpensive, easy to build,
doesn't require special materials or tools to build, and is tolerant of minor variations in construction. IOW, it's easily realizable."
--------------------------------------------------

Goodie on the "figuring." You HAVE an MSEE (you say) so that is a breeze, yes?

Do ALL amateur radio licensee residences have two trees? Of course they do! Doesn't everyone?

Are those two trees of yours lined up so that your desired DX is perpendicular to their line? Of course
they are! Aren't all trees lined up that nicely?

Are all licensed radio amateurs capable of climbing trees and attaching the dipole ends? Of course they
are! Isn't everyone?


N2EY: "I used two software packages:

http://www.ocarc.ca/coax.htm"

"To put some numbers on thus antenna, it's a 127 foot long single-wire center-fed dipole, 50 feet above
average ground, made of #12 copper wire. At that height, it's half-wave resonant at 3.75 MHz."

Right...and the weight/torsion/strain on the tree attachment point is how much? Naturally the typical ham residence tree is taller than 50 feet else it would bend too much at the top.

N2EY: "The transmission lines evaluated were:"

"100 feet of Belden 8237"

"and"

"100 feet of generic 600 ohm ladder line"

Tsk, that loads your comparison dice. First of all, Belden 9913 (also RG-8) has less loss than Belden
8237. Secondly, you are accepting the www.ocarc.ca website Projects calculator as accurate. Where is
the manufacturers reference for "generic 600 ohm ladder line?" Thirdly, the ocarc calculator says
"generic 600 ohm open-wire line," NOT "ladder line." Fourth, others have repeatedly referred to ladder line
as being 450 Ohm (nominal), which the ocarc calculator has but you didn't use it.


N2EY: "Seems pretty clear to me that this is a scenario where ladder line is clearly superior."

Seems to me you are up to your old newsgroup tricks of loading your "proof" so that your pre-conceived
conclusions become right. :-)

Let us just use four frequencies and the ocarc calculator (accepting their values for ladder-line for the moment) and compare 100-foot losses between Belden 9913 and 450 Ohm square-opening ladder line:

__F, MHz____db 9913____db Ladder Line____Difference
___3.5_______0.228________0.052____________0.176
____7________0.323________0.073____________0.250
___14________0.460________0.105____________0.355
___28________0.656________0.150____________0.506

There's all of a 'whopping' half db difference at 10m! Wow, you can actually hear a 0.5 db difference?
Amazing ears. Actually what you get is radiation patterns DIFFERING by MANY db between those bands depending on the direction from broadside to the 80m dipole.

HALF a db is not even close to being "clearly superior" in your comparison. 450 Ohm Ladder-line is
"superior" only in that it is CHEAP compared to Belden 9913 coaxial cable. It is physically lighter weight

(which you have not mentioned) compared to Belden 9913 so, with coax used from the 127-foot dipole center, a THIRD TREE would probably be needed (located equidistant between the two trees already mentioned) for center support of 50 feet of Belden anything.

I doubt that Vigoro could help anyone grow that third tree fast enough to be useful by the time of the peak
of the coming sun cycle.

By the way, what do you USE to measure decible loss down to three decimal places? You gottum Weinschel Attenuation Standard? A real gud buddie at NIST?

Now be a good lad and come up with a manufacturer's specification on the Loss of 450 Ohm Ladder Line
over frequency. That's a good lad...

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N6AJR on May 31, 2007 Mail this to a friend!
And here I thought I was the only EX OLD CROW on the block. I did 8 years on b-52's, f100's 105's, f4c, and such. ECM repairr. Not to mention a stint in the security service.



ECM, where Jam It takes on a whole new meaning.



Now go put up a fan dipole and work some DX
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on May 31, 2007 Mail this to a friend!
One of you asked why I didn't buy good coax after the war, causing me to buy damp coax and blow a jet of steam out of it.
In England as a kid I spent every afternoon of Elementary School days underground in bomb shelters.
We had no eggs, no bananas, and one day I came home to find that the War Department had cut off all our iron fencing to make ammunition.
Both cousins were killed flying - one a Lancaster and two weeks later one in a Spitfire.
There wasn't any coax even after the war.
Thank goodness I could make ladder line.
Gil
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 1, 2007 Mail this to a friend!
AF^AY says..."Let us just use four frequencies and the ocarc calculator (accepting their values for ladder-line for the moment) and compare 100-foot losses between Belden 9913 and 450 Ohm square-opening ladder line:

__F, MHz____db 9913____db Ladder Line____Difference
___3.5_______0.228________0.052____________0.176
____7________0.323________0.073____________0.250
___14________0.460________0.105____________0.355
___28________0.656________0.150____________0.506

There's all of a 'whopping' half db difference at 10m! Wow, you can actually hear a 0.5 db difference?
Amazing ears. Actually what you get is radiation patterns DIFFERING by MANY db between those bands depending on the direction from broadside to the 80m dipole."
-------------------
Now add in the loss of your matching device to come up with the true loss of the entire feed system. Personally I don't see what the arguments are about. The are reasons for using coax over ladder line and there are reasons for using ladder line over coax. Its all a matter of what you want to do, and where you want your antenna system to start. Can we move on to something else to argue over?? This subject is getting old now. Nothing wrong witha a good debate, but seriously I think some of you would argue with yourself!

73 de W4LGH - Alan
http://www.w4lgh.com




 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 1, 2007 Mail this to a friend!
Alan - but your figures are for SWR 1:1.
If SWR is say 13:1 could you post the figures?
And 13:1 is no problem with ladder line and enables you to have a multiband antenna if you have a genuine no-balun tuner.
Gil
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 1, 2007 Mail this to a friend!
W4LGH wrote:

"Now add in the loss of your matching device to come up with the true loss of the entire feed system."

Agreed!

In the antenna scenario I described, a tuner is needed regardless of whether the antenna is fed with coax or ladder line, except for a small part of 80/75 meters.
So that tuner loss factor affects both versions.

Many coax-fed antennas need a tuner as well - that's why so many modern rigs have an ATU built in. What about their loss?

N4SL has described his antenna system here in some detail. The results he gets with it are obvious from contest scores - and he makes those results without a tower or mechanically-rotatable antenna. Consistently, too. According to his description, he can run 1500W RTTY (which is 100% duty cycle) through his homebrew tuners without them getting warm. That's pretty low loss, isn't it? So it's about getting a good tuner, not avoiding the use of tuners.

"Personally I don't see what the arguments are about. The are reasons for using coax over ladder line and there are reasons for using ladder line over coax. Its all a matter of what you want to do"

I agree 100%. Well said! There are applications for both. Another tool in the toolbox.

But when you have somebody who claims to be an antenna expert repeatedly saying "Don't use ladder line. Ever." and "Ladder line is inherently unsafe" - well, that sort of bad and misleading information has to be challenged. Because a newbie might think it were true.

There's also the fact that antenna resources vary all over the place. Some people have lots of tall hardwood trees available - why not use them for antenna supports? All it takes is a slingshot, spinning reel and some line to get support ropes well up in the air.

Others have lots of open space, or a tall house that can be used for antenna support. Their antenna solutions will be different from those with trees.

Of course it would be great if we all had lots of room, lots of money, lots of time, no restrictions and could put up big towers for whatever antennas we wanted. Some folks can - good for them! But for the rest of us, figuring out how to make the most of what we have in the way of antenna resources is a challenge.

There's also the factor of what someone wants to do with ham radio. For example, at the bottom of the sunspot cycle, the upper HF bands are usually quite dead after the sun goes down. The ham whose operating time is mostly after dark needs an effective antenna for bands like 80 and 40 meters. The dipole I described is very effective on those bands if properly fed.

Some folks like verticals - that's fine if they can put down the radials and only want low angles of radiation. And if they can deal with the inefficiency and narrow SWR bandwidth (tuner, anyone?) of a loaded antenna on bands like 80 and 40, or the height of of a full-size antenna for those bands.

There's no one antenna solution for all hams. But when you see folks saying to *never* use ladder line, or denying the real-world scenarios posed by folks like me, well....

73 de Jim, N2EY



 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 1, 2007 Mail this to a friend!
You can prove all your antenna building results to yourself and others on the salt lake s-meter, dam i let out another secret..
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 1, 2007 Mail this to a friend!
G3LBS wrote:

"Alan - but your figures are for SWR 1:1.
If SWR is say 13:1 could you post the figures?"

They're not pretty...

http://www.ocarc.ca/coax.htm

is an online calculator that shows the effect of SWR on line loss. Easy to use and makes the case very clearly.

"And 13:1 is no problem with ladder line and enables you to have a multiband antenna if you have a genuine no-balun tuner."

Not only that, but in the example I gave (127 foot dipole at 50 feet, choice of coax or 600 ohm ladder line feed), the SWR with ladder line barely exceeds 10:1 on some bands, and is less than 7 to 1 on most bands.

AG6K developed a true balanced tuner back in 1990. His method is to use a 1:1 balun at the 50 ohm tuner input, and then a form of balanced L network (C network?) to transform the balanced 50 ohms to whatever was needed. Once a match is found, the balun works at its design impedance of 50 + J0.

And yet we are told to never, ever use ladder line.
Hmmmm...

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 1, 2007 Mail this to a friend!
one last thing, you have to ask yourself why being so dangerous and antiquated,and all the other nonsence that is being spewed on this thread, is MFJ PALSTAR and others are going through all the time and expence to copy and produce an exact replica of the johnson matchbox, which as we all know is an open wire only balanced line tuner, you just have to ask yourself why????
 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
Tell us another story chippy, pah leez, you should be writing for disney, aaa hhaa,, maybe thats where i'll find the book's you wrote, your still the best bullshi##er on this site

------------------------------

Unlike someone who uses ham article(s) to drive traffic to his website mainpage, where you find all kindsa info (not ham related) on all those books he writes, I don't use ham radio to do viral marketing.

Believe me, I could. But hams are cheap and it's too off-topic. So I don't.

I actually find it kinda distasteful: Write an article! Tap into 700,000 potential buyers! Niche that play!

But that's my opinion.

Funny how it ran over the heads of many here...

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
This topic is about 'antenna lessons from Old Timers' with an especial emphasis on a newbie audience. Being quite cognizant in matters of antennas, and an OT, my experienced advice is, and continues to be:

Don't use ladder line. Ever.

Now, those with some modicum of reading ability and memory can see my reasons for that, rather than being asked to digest foul bits of vituperative that claim to be reasoned responses to them.

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
You can prove all your antenna building results to yourself and others on the salt lake s-meter, dam i let out another secret..

----------------------------------

In my opinion sir, you are illiterate and incoherent. This prevents me from understanding your issues, and therefore makes it impossible to reasonably address them.

I don't know what Salt Lake; S-meters; dams; and secrets have to do with antennas. Or anything else.

And you apparently lack the facility to expatiate in a meaningful way to make such allusions relevant...

IMO.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 1, 2007 Mail this to a friend!
Chippy: do you even own a radio or antenna, are you on planet earth, there is not one amatuer on this site or anywhere on earth for that matter that doe's not know what i'm talking about except you, go somewhere else and spout your crap, leave the antenna forums on this wonderfull site to the amatuers that accually know about there radio and antenna systems, because you SIR bullshi##er do NOT have a clue, your doing nothing but wasting everyone's time having to gloss over your crapola to accually learn something from there fellow operators, i guarantee not one thing was learned from YOU, on this whole dam thread except that you don't have a clue, and your full of crap right up to your eyebrows
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 1, 2007 Mail this to a friend!
"my experienced advice is, and continues to be:

Don't use ladder line. Ever."

And as a seasoned newbie my advice is to put up a ladder-line fed doublet (and be careful of the high voltage) so that you can talk to people on the radio while you learn about other approaches.

"Now, those with some modicum of reading ability and memory can see my reasons for that, rather than being asked to digest foul bits of vituperative that claim to be reasoned responses to them."

The first reason given, of course, being that ladderline is antiquated and to use it is a sort of historical reenactment rather than a use of an effective transmission line for a conceptually simple antenna.


73,
Dan


 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
Chippy: do you even own a radio or antenna, are you on planet earth, there is not one amatuer on this site or anywhere on earth for that matter that doe's not know what i'm talking about except you, go somewhere else and spout your crap, leave the antenna forums on this wonderfull site to the amatuers that accually know about there radio and antenna systems, because you SIR bullshi##er do NOT have a clue, your doing nothing but wasting everyone's time having to gloss over your crapola to accually learn something from there fellow operators, i guarantee not one thing was learned from YOU, on this whole dam thread except that you don't have a clue, and your full of crap right up to your eyebrows

----------------------------------------

Sir, IMO you are functionally illiterate. Trying to understand what you are writing is like trying to understand someone's speech through a mouth-full of taffy.

Challenging, to say the least.

Is there someone else there who can take your thoughts and type them in? No offense, but it is a major encumbrance, IMO, to active participation in this forum.

I sort of discerned that you want to know what transceivers I have. At present I own:

IC-756ProIII
IC-7000
JST-245
VX-5

I do hope that helps; I don't know how else to help you.

73,
Chip W1YW


 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 1, 2007 Mail this to a friend!
Dan, longpath isn't active today to CN88xa. FYI.
 
RE: Antenna Lessons from the Old Timers  
by AC2Q on June 1, 2007 Mail this to a friend!
IF you are using a wire antenna of any type on multiple bands, AND you have the tuner located at the input to the feedline, THEN coaxial feedline will exhibit more loss than Ladder line or Open Wire line, unless you route the Open Line in close proximity to a metal object.

I think the Article Is Excellent, very Good Job.

P.S. If you ever setup your Antenna System so that the tuner is at the Antenna Feedpoint, you will never go back. I have had this setup for years and it is outstanding. Yes, I am now using coax, yes, it is buried, BUT if I did not have the matching network located at the Antenna Feedpoint, I would see signifigant loss in the coaxial feedline.

KF8ZN
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 1, 2007 Mail this to a friend!
N9FE, Chip knows his stuff. He really does. If you look around calmly, you'll see it. He just chooses to obscure his valid and interesting points in a maddening shell of verbal gymnastics and bombast. It's a fine old academic tradition perhaps, but it doesn't fly on the internets.

Don't let him get to you, you'll just raise your own blood pressure. Trying to get Chip to stop doing what he's been doing in ham forums for at least a decade is about as effective as trying to work DXCC from the interior of a copper box.

Dan
 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 1, 2007 Mail this to a friend!
KF8ZN: I take it you have your outdoor tuner at the feed point well sealed to the weather, good deal
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on June 1, 2007 Mail this to a friend!

"I actually find it kinda distasteful: Write an article! Tap into 700,000 potential buyers! Niche that play!"


>> Maybe someday your competitors will:


http://www.3g.co.uk/PR/Feb2006/2554.htm

http://www.bbwexchange.com/pubs/2006/05/09/page1381-136493.asp

http://www.evertiq.com/newsx/read_news.aspx?newsid=7692&cat=2


Richardson is a big win for Fractus:

http://rfdesign.com/news/Richardson-Fractus-agreement/



...WA1RNE
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 1, 2007 Mail this to a friend!
G3LBS wrote: "Alan - but your figures are for SWR 1:1. If SWR is say 13:1 could you post the figures?"

I didn't post any figures. If you look at the post you'll see I copied and quoted what someone else said.
I don't post figures like that. I am an engineer, and I know the figures can be misleading, depending how it was calculated, as there is always more than one way to work them. Most figures that I post are measured figures. I do own commercial test gear, such as spectrum analyzers, rf generators, scope, and antenna analyzers. Not bragging, just explaining how
I come up with my numbers. As I have said, if you want your antenna system in your shack, use ladder line and a tuner, if you want to get your antennas away from the shack, then use coax. There are advantages and disadvantages to both. If you are using coax, and hooking it to a tuner in your shack, you are ONLY FOOLING your radio, and NOT tuning your antenna, to do this the tuner would have to be at the antenna.

If using a tuner hooked to your coax makes you feel better, then so be it, by all means use it, but you still have the same reflected power on your antenna.
There are those who will argue until blue in the face that it will tune the antenna or "Antenna System" but using coax puts the "Antenna System" at the end of the coax, PERIOD!

73 de W4LGH - ALan
Http://www.w4lgh.com

 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
N9FE, Chip knows his stuff. He really does. If you look around calmly, you'll see it. He just chooses to obscure his valid and interesting points in a maddening shell of verbal gymnastics and bombast. It's a fine old academic tradition perhaps, but it doesn't fly on the internets.

Don't let him get to you, you'll just raise your own blood pressure. Trying to get Chip to stop doing what he's been doing in ham forums for at least a decade is about as effective as trying to work DXCC from the interior of a copper box.

Dan
--------------------------------

Dan--

Could you kindly screen N9FE's posts before they go up?

If they were made understandable then they could be considered a basis for further discussion.

Otherwise I will have to ignore them as persiflage, along with the other dross here.

 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 1, 2007 Mail this to a friend!
Dan: you or anyone else do not have to screen my posts, as i will no longer subscribe to this site.. thank you... N9FE
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 1, 2007 Mail this to a friend!
"If they were made understandable then they could be considered a basis for further discussion."

If you adopted a style that was less likely to make people blindingly angry, you'd be more of an asset to ham radio forums.

If you want to have further helpful discussion, you might consider directly rebutting or discussing the technical points made by those who are not merely yelling at you, even if they're yelling at you a little.

Or maybe even the points made by those who aren't yelling at you at all.

To this end, let me ask a pair of direct questions, simply:

Is antenna innovation the most important goal of the Amateur Service?

If not, is a ladder-line fed doublet inconsistent with the Part 97 goals if it allows hams to effectively advance in Amateur Radio activities outside of antenna innovation?

Dan
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on June 1, 2007 Mail this to a friend!
I am sorry i know i said i would not post any more in this forum.But i have to admit i personally am getting the best entertainment here of any recent things i have done. Now to risk the fact i may be sued to defamation agian. I too would agree Chip is not a stupid person.

But his posting's can be really a hoot to read. Guess thats why i enjoy seeing forums where chip is in keep going. IMO it is like monty pyhons flying circus. and now for some thing completely differant :)

Altough i must admit i personally enjoyed the crow story. and i will not add my thoughts to that. But i will state for the record i do posses to rather unique
military (army) awards to place agianst your sharp shooter rating. the first beeing the Hawkeye award.
and the second being Expert infantry.

Hence i would most likely have no clue how well any weapon, firearm, other other projectile dispering implement would likely work or the range of such devices.

Ah crap i have to stop i cant see to type i am laughing way to hard now. he atleast i have not defamed any one yet. Well maybe my self but then what am i going to do about that it is my self right ?
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 1, 2007 Mail this to a friend!
"Dan: you or anyone else do not have to screen my posts, as i will no longer subscribe to this site.. thank you... N9FE"

N9FE, I'd probably leave this thread behind and not look back, but don't blame this on eHam. If eHam didn't exist, Chip would just find another forum in which he could type calm, well constructed sentences and get violent responses in return.

W1YW/N1IR: Knowing where your buttons are since at least the mid-90's.

;-)




 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 1, 2007 Mail this to a friend!
It's possible for academics to think about things so long and hard that they become incapable of doing them, or writing about them in plain English.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 1, 2007 Mail this to a friend!
Only if they want that to happen.

 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
W1YW/N1IR: Knowing where your buttons are since at least the mid-90's.

;-)

---------------------------------

Well, no.

What's changed is more than three orders of magnitude in my net worth, and the amusing ability to be an observer to comments that actually benefit my 'case', as they say.

My hot buttons deal with a slew of things I never had to consider 10 years ago. Haven't seen anything here that gets close. But it really is droll to see the utter ignorance with my respect.

I actually savor it. It is always rewarding to have a bead on the sociobiology of one's own species, don't you think?

BTW, Arecibo is shutting down...do you suppose someone or some group may...buy it?

Food for thought.

Now young man: what are you doing with YOUR life? How are YOU better today than yesterday? Who have you helped improve today? What have you done--right this minute--to make the world a better place?

These are issues that are important to young vital people.

Are you one? Or are you wasting your time trying to push on a mountain?
 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
the first beeing the Hawkeye award.
and the second being Expert infantry.

--------------------------------------

Congrats. Thank you for aspiring to them in the service to our country.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N3JBH on June 1, 2007 Mail this to a friend!
Chip i am most touched by that reply. I am serious Thank you very much.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 1, 2007 Mail this to a friend!
"It is always rewarding to have a bead on the sociobiology of one's own species, don't you think? "

It makes for easy manipulation of tense situations, at any rate.

"are you wasting your time trying to push on a mountain?"

Let me again ask a pair of direct questions, simply:

Is antenna innovation the most important goal of the Amateur Service?

If not, is a ladder-line fed doublet inconsistent with the Part 97 goals if it allows hams to effectively advance in Amateur Radio activities outside of antenna innovation?

Dan

By the way, you'd have one hell of a moonbounce signal.

 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
Chip i am most touched by that reply. I am serious Thank you very much.
--------------------------

My pleasure.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 1, 2007 Mail this to a friend!
"It's possible for academics to think about things so long and hard that they become incapable of doing them, or writing about them in plain English."

Not just possible - it's easy.

Writing and talking about complex things in complex terms is easy compared to talking about complex things in simple, plain-English terms.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 1, 2007 Mail this to a friend!
"There are advantages and disadvantages to both. If you are using coax, and hooking it to a tuner in your shack, you are ONLY FOOLING your radio, and NOT tuning your antenna, to do this the tuner would have to be at the antenna."

Agreed, except there's nothing really wrong with "fooling" the rig unless doing so also introduces a lot of loss into the system.

"If using a tuner hooked to your coax makes you feel better, then so be it, by all means use it, but you still have the same reflected power on your antenna."

Yup. Which may or may not be a problem. For example, if you have, say, 50 feet of decent coax to an antenna that presents a 3:1 SWR on 40 meters, using a tuner at the rig to get the SWR down to 1:1 will be OK if the tuner isn't too lossy. OTOH, if you have 120 feet of coax to an antenna that presents a 30:1 SWR on 15 meters, the results aren't going to be pretty.

"There are those who will argue until blue in the face that it will tune the antenna or "Antenna System" but using coax puts the "Antenna System" at the end of the coax, PERIOD!"

Well, that depends how you define "Antenna System".

If you mean that the "Antenna System" is the part that intentionally radiates the RF, then the Antenna System starts at the far end of the feedline, regardless of whether it's coax or ladder line.

But if you mean that the "Antenna System" includes the antenna itself, the transmission line, and any matching devices, then using a rig-mounted tuner makes the transmission line part of the antenna system.

With ladder line, you have to worry about line balance. With coax, you have to worry about common-mode currents, AKA "RF on the outside of the coax". Both have their causes and cures.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 1, 2007 Mail this to a friend!
N2EY: "http://www.ocarc.ca/coax.htm is an online calculator that shows the effect of SWR on line loss. Easy to use and makes the case very clearly."

That's nice but WHERE is any ladder-line (or open-wire) Loss v. Frequency from a manufacturer?

The Canadian applet uses SOMETHING as a basis for "generic ladder-line" and "generic open-wire-line' but that basis IS NOT SHOWN.

N2EY: "AG6K developed a true balanced tuner back in 1990. His method is to use a 1:1 balun at the 50 ohm tuner input, and then a form of balanced L network (C network?) to transform the balanced 50 ohms to whatever was needed. Once a match is found, the balun works at its design impedance of 50 + J0."

Ahem...a broadband RF transformer does NOT have a "design impedance of 50 + j0." Had you built and tested any broadband RF transformers you would understand that. Philips has a couple of nice Application Notes on broadband RF transformers that go back 30+ years and they've been "reprinted" and available at the Philips website. W6MJN and I have used the original back in the earlier 1970s. Hint: They are designed for FREQUENCY range, and that MUST take into account the toroidal core characteristics over frequency. With today's (and those of three decades ago) core materials one can pick any RF range from LF to UHF, no sweat. Once you establish the frequency capability, THEN you look at the RANGE of source-load resistances (it's usually quite wide). The last step in design is to see how well the RANGE reactive parts transform input<->output. That's also quite wide but depends on the transformer model's Mutual Inductance as well as the primary-secondary inductances.

Oh, and a "Balun" name just means how it is used; i.e., with two windings and four connections, both ends of one winding connected to a balanced line, the other winding's two ends connected to an unbalanced line. Hence the contraction/acronym of "Balun."

If you follow broadband RF transformer rules, the impedance (or admittance if you prefer, you don't) on one side of a Balun will be repeated very closely on the other side of a Balun, scaled according to the turns ratio squared. Any good VNA can show the scaling of the impedance...and with varying impedances (or admittances) on the side to be transformed. A Vector Voltmeter can do that. Even a Noise Bridge can do that, although the measurement time takes a lot longer. Those few of you who have RF Bridges will show that. Baluns just aren't automatically "designed for 50 + j0" Ohms. Hint: They are designed for a frequency range. They can work in 75 Ohm systems just as well without changing anything on the insides; millions of 4:1 Z-ratio Baluns have been made and sold with TV receivers worldwide and all of those will work just as well as 4:1 Z-ratio Baluns for 200:50 Ohm low-power work.

N2EY: "And yet we are told to never, ever use ladder line."

If we listen to you, we should never ever use coaxial cable directly from dipole feedpoints; we MUST use balanced line. Hint: Get a combination Balun and feedpoint insulator component, use that with coax feedline, with or without a tuner (unbalanced input/output). Direct to coax all the way to the transceiver.
Or, if your "typical two trees at every ham's residence" are too weak, drop with balanced line to a Balun on the ground, then go coax to the transceiver. Or, follow 60-year-old information that keeps getting REpublished EXACTLY as it was done in olden days and forget about doing any modern alternatives...alternatives that might be better at another ham's residence. If someone has alternatives, spend lots of time on the computer and berate them for "not following [sacred] tradition." [shame on them, huh?]

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 1, 2007 Mail this to a friend!
N6AJR: "And here I thought I was the only EX OLD CROW on the block. I did 8 years on b-52's, f100's 105's, f4c, and such. ECM repairr. Not to mention a stint in the security service."

The Association of Old Crows has all members of the Electronic Warfare community in it, military and civilian. I was never in it as a member but did associate with several for particular contract jobs. I was in the design end of EW. My ancestors bred the origninal ravens. :-) Except for the old, obsolete Quail missle, I think most of the stuff I worked on is still operational. Although sometimes (in re EW) I feel like all those mothballed ships on Suisun Bay. :-(

N6AJR: "ECM, where Jam It takes on a whole new meaning."

Heh heh, you can say that again, like survival versus extinction. :-)

N6AJR: "Now go put up a fan dipole and work some DX"

Not much HF "DX" with the recent X-Ray spike. VHF local is still good down in L.A. I'm going Vertical for HF. I go horizontal only at night.

Good home page on AOL! You sure got a collection of toys there!

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 1, 2007 Mail this to a friend!
"MFJ PALSTAR and others are going through all the time and expence to copy and produce an exact replica of the johnson matchbox, which as we all know is an open wire only balanced line tuner, you just have to ask yourself why????"

Two reasons:

1) They realized that an "old fashioned" true balanced tuner has some serious advantages over the more-modern unbalanced-tuner-followed-by-a-balun setup

2) They realized that there are more than a few hams who understand the advantages of such tuners.

And there are other options:

http://www.somis.org/bbat.html

Two inductors, one capacitor, one switch, and a balun that's either a coil of coax on a piece of PVC pipe, or a bunch of ferrite beads on coax.

The design is a natural for remote control, too.

Although the article used roller coils, tapped coils and a switch would work. You'd have to find the taps for each band when setting up for the first time with an antenna, but once done, you're set.

If a coil-of-coax or ferrite-bead balun is used, the tuner can be converted to an unbalanced tuner by simply grounding both ends of inductor that connects to the coax braid.

(insert standard no-connection disclaimer HERE)

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by WA1RNE on June 1, 2007 Mail this to a friend!

"Well, no.

What's changed is more than three orders of magnitude in my net worth, and the amusing ability to be an observer to comments that actually benefit my 'case', as they say."


>>> Well, barf me Nathan. You better not be near a pin, you may pop.

Any more pathetic outbursts of this nature and eHam's server may attempt to cleanse itself and barf some bits on you.


...WA1RNE


 
Antenna Lessons from the Old Timers  
by W1YW on June 1, 2007 Mail this to a friend!
Well, no.

What's changed is more than three orders of magnitude in my net worth, and the amusing ability to be an observer to comments that actually benefit my 'case', as they say."


>>> Well, barf me Nathan. You better not be near a pin, you may pop.

Any more pathetic outbursts of this nature and eHam's server may attempt to cleanse itself and barf some bits on you.


...WA1RNE

--------------------------------------

What a pity your little digression to old 'news' failed to have the intended effect...
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 1, 2007 Mail this to a friend!
N2EY: "MFJ PALSTAR and others are going through all the time and expence to copy and produce an exact replica of the johnson matchbox, which as we all know is an open wire only balanced line tuner, you just have to ask yourself why????"

Two reasons:

1) They realized that an "old fashioned" true balanced tuner has some serious advantages over the more-modern unbalanced-tuner-followed-by-a-balun setup

2) They realized that there are more than a few hams who understand the advantages of such tuners."

----------------------

I have Martin's 2007 catalog. On the cover page is their MFJ-998 "intelliTuner," an automatic (i.e., microprocessor-controlled) antenna tuner with unbalanced input and output. On the second page are three more "IntelliTuners" of lesser power handling. The MFJ-998 specs are for 1.5 KW RF.

Pages 3 through 10 have more antenna tuners, those being manual-tuning models. My take of MFJ's approach to selling product is that they are trying to cover ALL bases...they have a kind of tuner to fit every customer's idea of the "perfect" tuner. All of them do the job advertised. MFJ makes a LOT of different products and is allied with Hy-Gain, Mirage, Vectronics, Ameritron in their 88-page 2007 catalog.

Martin F. Jue long ago figured out how to market products. MFJ has been around a while, expanding all the while. But, face the facts, MFJ is NOT some saintly enclave of ham engineering gurus. Most of their products show good engineering design, yes, but not all. I have their MFJ-269 antenna analyzer which does NOT show sign of reactance when displaying the complex impedance (ads imply that it does), therefore I'd say they didn't carry out the design as far as they could. The MFJ-264 HF-UHF dummy load tests very good (and mostly resistive) on up to 70cm, which I'd call good...but how much wrong could one get with a box that has a large relatively-temperature insensitive power resistor? :-)

N2EY: "Two inductors, one capacitor, one switch, and a balun that's either a coil of coax on a piece of PVC pipe, or a bunch of ferrite beads on coax."

Oh, my, you must really HATE toroidal transformers of the broadband RF variety! :-) Bill Amidon has been offering a 1 KW plus Balun kit through stores for at least three decades. Those work rather well if made as directed (the kit has large enameled solid wire included for the buyer's convenience).

The microprocessor-controlled automatic antenna tuner uses just ONE bank of capacitors, ONE bank of inductors (evil toroids again, gasp!). Typically they use latching relays so that no relay power is consumed once tuning is done. To cover impedances above or below the impedance center (typically 50 Ohms magnitude), the capacitor bank is relay-switched between "input" and "output" ports. It really can't get much simpler than that. Bells and whistles are additions to the basic function. My LDG-100Pro has a bar-graph power output indicator plus manual stepping of "more" or "less" C or L. It matches good enough from a not-already-in-memory frequency in a couple seconds. It also controls the low-power "tune" output of IC-746Pro to minimize interference to anyone else on that frequency during those two seconds.

N2EY: "The design is a natural for remote control, too."

Just how "natural" is a MANUAL tuner for "remote control?" One adds motors and stepping switches?

N2EY: "Although the article used roller coils, tapped coils and a switch would work. You'd have to find the taps for each band when setting up for the first time with an antenna, but once done, you're set."

Fine if you want the smug satisfaction of doing everything absolutely manually. Not for me. I began doing that with HF transmitters eight hours every shift (at least 30 out of 36 on-line and at least one QSY per shift for all that were on)...54 years ago. No "antenna tuners." Whatever was in the final had to be tuned manually. There's more to life than twisting knobs beyond the frequency tuning...

N2EY: "(insert standard no-connection disclaimer HERE)"

No sweat, there's not much "antenna tuning" going in railroad signalling. No danger to Conrail being compromised. :-)

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 2, 2007 Mail this to a friend!
No sweat, there's not much "antenna tuning" going in railroad signalling. No danger to Conrail being compromised, Now i know why the same people are on this site daily. I hope you and chippy have a nice life together, The rest of us in the real world will keep building are own tuners and antenna systems, and trying hear the S-nothing signals coming from those who don't have a clue,, what a waste of a good web site
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 2, 2007 Mail this to a friend!
AF6AY says...."Two reasons:

1) They realized that an "old fashioned" true balanced tuner has some serious advantages over the more-modern unbalanced-tuner-followed-by-a-balun setup

2) They realized that there are more than a few hams who understand the advantages of such tuners."

===============================

Actually what the realized was that there was a MARKET for these devices, and they could actually sell and few and TAKE your money!!! There is a company here in Florida that still makes and SELLS that little "MAGIC" box to make you antenna work ANYWHERE, and people buy them everyday! (I would like to see one and disect it!)

73 de W4LGH - Alan
http://www.w4lgh.com
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 2, 2007 Mail this to a friend!
"Actually what the realized was that there was a MARKET for these devices, and they could actually sell and few and TAKE your money!!!"

You're absolutely right! Thanks for pointing that out. Make that Reason #3.

Actually, it should be Reason #1, and the other two reasons should be made #2 and #3.

--

Which brings up an important fact:

Just because something is manufactured and sold, or used by "PROFESSIONALS", doesn't mean it's the best solution to a problem.

Most hams cannot easily homebrew flexible coax cable. (Hams have homebrewed rigid coax, but that's a different thing).

But many if not most hams *can* homebrew ladder line pretty easily. Modern plastics make home fabrication of high quality spreader insulators much easier, faster and less expensive than in the past.

Coax also uses relatively expensive connectors and can require periodic replacement.

So the profit margin for coax is usually much greater than for ladder line. All the more reason for those seeking to sell to hams to push coax as the only solution for all applications, and to advise newcomers to 'never, ever use ladder line'.

And it's not just about ladder line. Consider the simple dipole - whether fed with coax or ladder line, it's a pretty practical homebrew project. Same for a simple L-network tuner, balanced or unbalanced.

Take a look at this example:

http://www.somis.org/bbat.html

---

What I'm saying is that if you look carefully, you can see some "PROFESSIONAL" folks trying hard to push us hams away from simple, effective, time-proven solutions to problems, and into *buying* complex "new" gadgets that cost more and can't be easily homebrewed.
And they point to commercial and military practice as examples of what hams should do, even though the needs and resources of amateurs and commercial/military users are usually very different.

For example, consider the PRC-104. Certainly it's a rugged portable HF radio set, and did its design job very well.

But as an *amateur* transceiver, it leaves a lot to be desired, beyond just size/weight/cost. No RIT, split operation, no memories, no second VFO, no sharp filters. Requires nominal 24 volt power, rather than 12-14 volts. Power consumption in watts is high compared to many amateur sets.

If a ham wants a PRC-104 for nostalgia reasons, that's fine, but it's certainly not the best choice on a performance or cost basis, even if it's what the "PROFESSIONALS" use.

--

73 de Jim, N2EY



 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 2, 2007 Mail this to a friend!
I designed a remote tuner for my friend, KY5G (and he built it).

He has a large piece of property with very tall trees at one end, the top of a big hill. His house is all the way down the bottom of the hill, about 450' away.

I put up a 400' center fed Zepp, shot up between two really tall trees w/ a bow and arrow. It's up about 110' high at the center. Fed w/ 600 Ohm open wire line to a 'doghouse' with an L-match made from Palstar roller coil and a big open-air variable cap. The doghouse is a Tupperware container with feedthru connectors installed (plus a wooden outer cover for UV and intruder protection).

Put small DC motors on each shaft (series RF chokes just-in-case) and ran the 4 wires down along with his low-loss hardline to the shack.

Using a homebrew controller w/ current-limiting and a reversal switch to change direction (momentary contact +/- with an off-center, very intuitive), you can adjust the C and L AND detect when you have hit either mechanical stop on the L (an LED lights when it's in current limit).

Tunes and works beautifully on 160-40 (he has big beams up for 20-6), kicks ass and takes names, huge fun. Running QRO on 160m, he has people in the midwest asking if he's a local. He has people breaking in to ask is he's a local!

Of course, w/ an L match you must have the load Z either always greater than 50 or less than 50 ohms, that's the limitation, but it was determined by modelling we'd always be greater than 50 Ohms.

I have all the details of this including where I got the motors, their PNs, the schematic for the controller, pictures, etc. if anyone wants it, just email me at n4sl AT yahoo DOT com

The only thing that surprised us was how easily we could tune it remotely without actually knowing the number of turns on the L and where the C was on it's rotation. Just set the L to minimum, then run it out for 'n' seconds, then dip the C, then fine tune.

If we were forced into a T match, I think it would be pretty hard to tune remotely without knowing where the caps were in their rotation. Some talk of putting a tiny IR camera inside the box and running it's video down to the shack was discussed (after a couple of 807's) but we kept it simple. 4 wires + feedline. Adjust the voltage to get the speed you want, adjust the current limit (torque limit) to prevent damage when you hit the mechanical stop or if something were to jam.

OK, go ahead back to yelling.
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 2, 2007 Mail this to a friend!
A good first project for a new ham is to build a Salt Water Dummy Load, rather than cause QRM by tuning up on the antenna.
Gil
 
Antenna Lessons from the Old Timers  
by W1YW on June 2, 2007 Mail this to a friend!
A salt water dummy load can be a POOR project because:

1) it heats up dangerously over time for powers exceeding 100 watts--IT CAN EXPLODE. SAFETY WARNING!;
2) it is inconsistent over time because it works best with near saturation of salt, and the salt precipitates. AT the VERY LEAST remember to shake it at a warm temperature before each use;
3) it's SWR changes with temperature;
4) it will essentially not work in cold weather;
5) it radiates( hopefully poorly), since the load is not balanced. You have to choke it at the load;
6) salt is corrosive and will pit and destroy the electrodes over time;
7) 50 ohms is do-able, while other load values may not be attainable.

This is the equivalent of the 'lemon electrode digital clock'. or 'potato battery radio'. If your ham radio experience is equivalent to Beakman's World (sic) or you think we live on the set of Jerico,then this may be on your agenda. At LEAST keep caution up as per the above considerations.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 2, 2007 Mail this to a friend!
Have you made one of these?
Gil
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 2, 2007 Mail this to a friend!
Surely you are incorrect to say it needs saturation - only a half teaspoon of salt in a pint of water should get you to 50 ohms. Your contribution makes me cautious not of the Dummy Load but of your 'facts'.
Here is a link - http://www.qsl.net/k5lxp/projects/SaltLoad/SaltLoad.html

Gil
 
Antenna Lessons from the Old Timers  
by W1YW on June 2, 2007 Mail this to a friend!
Have you made one of these?
Gil
--------------
Duh. Yes. Several.
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 2, 2007 Mail this to a friend!
N2EY: "Just because something is manufactured and sold, or used by "PROFESSIONALS", doesn't mean it's the best solution to a problem."

Here's a clue on word definitions: "Professional" means an exchange of services for money. As such, if a lot of money is exchanged, the service is quite good.

I've yet to encounter an amateur radio supply store/chain that voluntarily gave away antennas or feedlines (of any type).

N2EY: "Most hams cannot easily homebrew flexible coax cable. (Hams have homebrewed rigid coax, but that's a different thing)."

I don't think Andrew Corporation is worried about such competition. :-)

N2EY: "But many if not most hams *can* homebrew ladder line pretty easily. Modern plastics make home fabrication of high quality spreader insulators much easier, faster and less expensive than in the past."

Right....UV proof polymers separating never-oxidizing wire. Polymers never out-gas or depolymerize, right? Ham wire never corrodes, right? :-)

N2EY: "Coax also uses relatively expensive connectors and can require periodic replacement."

Right...never mind that they can last two to three decades with simple tape-wrap protection around barrel splices. Open-wire and ladder-line needs only to twist the bare ends together and lasts for decades. :-)

N2EY: "So the profit margin for coax is usually much greater than for ladder line. All the more reason for those seeking to sell to hams to push coax as the only solution for all applications, and to advise newcomers to 'never, ever use ladder line'."

Right...damn those dirty rotten capitalists! Always wanting to make a profit! :-)

Anyone in here is a seller of those nasty coax things?

N2EY: "And it's not just about ladder line."

Right...it's all about re-creating the PAST with its "ultra-simple, ultra-cheap" methods...kind of like what some of the oldies think they did in Their beginnings. :-)

N2EY: "Consider the simple dipole - whether fed with coax or ladder line, it's a pretty practical homebrew project."

It is profound IGNORANCE to feed a transmitter's coaxial line into a dipole directly. You WILL get stray RF all up and down the coax outer conductor. One transforms unbalanced coaxial cable into some form of balanced form to feed a dipole. Hello? Do you wish to tell newbies myths of feeding a dipole directly with coax?

N2EY: "What I'm saying is that if you look carefully, you can see some "PROFESSIONAL" folks trying hard to push us hams away from simple, effective, time-proven solutions to problems, and into *buying* complex "new" gadgets that cost more and can't be easily homebrewed."

Poor guy, still in a snit over Professional versus Amateur over on RRAP? [you sure are...]

N2EY: "And they point to commercial and military practice as examples of what hams should do, even though the needs and resources of amateurs and commercial/military users are usually very different."

I've pointed out EXAMPLES of WHAT MIGHT BE DONE in other radio services for years. My IC-746Pro has a built-in antenna tuner with unblanced (coaxial) output...and Icom designed that model absolutely for amateur radio, no other radio service. [amazing, but true!] Darn the Las Vegas store of AES for "pushing that radio on me!" :-)

N2EY: "For example, consider the PRC-104. Certainly it's a rugged portable HF radio set, and did its design job very well."

Just HOW do you KNOW that? You've never been in any military service and your hands have never touched one.

N2EY: "But as an *amateur* transceiver, it leaves a lot to be desired, beyond just size/weight/cost."

Tsk, it wasn't designed for amateur radio use. :-) I wore one once as a civilian...weighed about the same with about the same size as the backpack AN/PRC-8 VHF transceiver that I'd worn many, many years before in the US Army.

N2EY: "If a ham wants a PRC-104 for nostalgia reasons, that's fine, but it's certainly not the best choice on a performance or cost basis, even if it's what the "PROFESSIONALS" use."

Tsk, it ain't available as war surplus yet. :-) It's still operational with the US MILITARY. Wait a few years. :-)

Now you take a look at the (now-discontinued) SGC-2020 SSB transceiver. It has amazing similarity to the AN/PRC-104 as a radio transceiver...same PEP, same primary power drain, same physical cubic size (but without the PRC-104's automatic antenna tuner). SGC still sells automatic antenna tuners. The SGC-2020 was made in an "amateur" model and a "marine radio" model, the main difference being restricted frequencies for the amateur model, something built-in to that model's microprocessor. SGC was begun by Don Stoner and Pierre Goral (rest their souls) and Don Stoner was certainly a "presence" in US ham literature four decades ago. The SGC-2020 has been reviewed on the Antennex website and came up favorable for a little QRP SSB rig.

I mentioned the AN/PRC-104 as an aside, trying to point out that it had an automatic antenna tuner BUILT-IN to cover the entire HF range using only a whip antenna. IF you had really wanted to critique that technically, you should have pointed out the "inefficiency" of trying to radiate power at 3 MHz from a few feet of whip antenna. Of course it won't be "efficient." Did you think a foot soldier could carry a 60-foot vertical antenna on their back for 4 MHz operation?!? However, there exists some MILITARY cures in the form of a "field expedient" wire antenna (several types given in the OM and TM) and a "half-rhombic" (vertical) wire antenna. The BUILT-IN antenna tuner of the AN/PRC-104 can handle those external antennas no sweat.

BTW, I've operated a "marine model" of the SGC-2020 from a rather large sailboat. On maritime frequencies of course. Outboard antenna tuner also by SGC (don't recall the model number) and the antenna itself was vertical. Could a catamaran use a dipole? :-) No "RIT" necessary. The built-in crystal ladder IF filter seems to yield very good voice reception. I don't recall a KEY connection on it but the PTT switch on the microphone might suffice for die-hard morseaholics. :-)

37 1/2, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 2, 2007 Mail this to a friend!
W4LGH wrote:
----------------------------------
AF6AY says...."Two reasons:

1) They realized that an "old fashioned" true balanced tuner has some serious advantages over the more-modern unbalanced-tuner-followed-by-a-balun setup

2) They realized that there are more than a few hams who understand the advantages of such tuners."
-----------------------------------

Ahem...AF6AY didn't write the above, N2EY did... :-)

W4LGH: "Actually what the realized was that there was a MARKET for these devices, and they could actually sell and few and TAKE your money!!! There is a company here in Florida that still makes and SELLS that little "MAGIC" box to make you antenna work ANYWHERE, and people buy them everyday! (I would like to see one and disect it!)"

Agreed. [pun in that if the A is separated...:-) ]

Well, there's bound to be a company somewhere that will sell magic boxes to hams. I happened to highlight MFJ since that was the first logo N2EY wrote. MFJ plays both sides, the automatic (using just a C and L bank) and manual (using variable Cs and Ls in a variety of combinations).

The point in actual operation is to transfer as much power as possible into the antenna. However, the point with some folks is NOT that...it is to DO IT THEIR WAY - OR ELSE! :-)

Another point seems to be that ALL newbies MUST recreate the old days of sixty to fifty years ago when that is a ludicrous exercise in many cases. <shrug>

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 2, 2007 Mail this to a friend!
W1YW wrote:
---------------------------------------
A salt water dummy load can be a POOR project because:

1) it heats up dangerously over time for powers exceeding 100 watts--IT CAN EXPLODE. SAFETY WARNING!;
2) it is inconsistent over time because it works best with near saturation of salt, and the salt precipitates. AT the VERY LEAST remember to shake it at a warm temperature before each use;
---------------------------------------

Quite right. Back in 1957 the Environmental Lab at Hughes Aircraft El Segundo Division (CA) had a task to make a salt-water load for testing something. I wasn't in on it, had relays to check. Looked beautiful when built out of 1/2" to 1" thick Lucite with lovely seams. Before use. [I think some specs called specifically for a "salt water" load - why I don't know] Good techs built it according to instructions. Same good techs had one devil of a time trying to keep the DC resistance within +/- 50%...heating kept evaporating the water, thus changing the salinity of the "load." Almost exploded once, got the salaried folks quickly to the back area where the test was going on. After three weeks of testing the once-beautiful structure was a MESS with corroded electrodes, salt encrustation drooling over the edges. Big high-level conference, heard much palaver was done in there, test postponed until we could scramble up enough dry power resistors to make the test load. Test completed over two months late.

That was at DC. I hate to think of doing manual impedance measurements at RF (no automatic analyzers in 1957) while that load was constantly changing characteristics!

That's why I have an MFJ dry dummy load that will withstand 100 W continuou for 10 minutes (spec.). I've measured its characteristics from AM BC on up to the '450' band and it remains good.

73, Len AF6AY

 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 3, 2007 Mail this to a friend!
At DC wouldn't it be elecrolyzing the solution? Was there a vent? How big was the container?
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Gee Gil,

It looks like you owe me an apology, for getting the "facts right". Comin a cropper there old boy....

Look: IF I TELL YOU THERE ARE SAFETY CONCERNS with something tkeep your hairs down and INSTRUCT the newbies. Keep the personal stuff out of it.

If someone ends up blind; burned; electrocuted; out of house and home, etc, because a FEW of you guys wish to project a niche bunch of old ham technologies as MAINSTREAM, then AT LEAST let someone who is KNOWLEDGABLE WARN about safety issues--and THEN AGREE WITH IT.

You (a choice few) are acting like a bunch of juvenile delinquents, IMO, forced to listen to the gospel at detention...

73,
Chip W1YW

 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 3, 2007 Mail this to a friend!
Have you read the link I sent you with the temperature graphs?
If DC was used, you would indeed electrolyze the solution and produce sodium and chlorine but why would anybody want to use DC through a dummy load?
Why would it explode if RF were used and the tank were vented?
Gil
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Lookit:

READ what I said and don't lecture me on someone else's home science experiment.

I suppose the next thing you'll want to defend is making one in a beer bottle, where the LIKELIHOOD of a 'bottle rocket' of corrosive, superheated steam is high enough to send some naive ham into a burn center for months.

Just drop it. It's a stupid and dangerous idea.

Or build one yourself and run your 100 watt plus rig into it from a safe distance and watch it change impedance; heat up; and make a mess of your garden--but with these **SAFETY CAUTIONS**, that is KEEP AWAY and watch out for rig damage, not your face.
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Why would it explode if RF were used and the tank were vented?

------------------------------------------
Is there some reason why you can't reason it out for yourself?

Where's the 'venting' on your beer bottle? What happens to water mixtures, left alone, when 'vented'?

Why are you defending this stupid device? It's not part of ham radio 'lore' and, to say the least, not used in ham radio or anywhere else.

If you want to DEMONSTRATE that RF dissipation can lead to heating, it is instructive.

In any case, YOU are the one who suggested this stupid and dangerous option to newbies, so it is YOUR ONUS to explain and defend. Don't waste THEIR time with a web link. Get out there, do it yourself, and report back.

BUT BEWARE--NOTE THE SAFETY ISSUES!
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 3, 2007 Mail this to a friend!
Did someone say "dummy load"?

For a 50 ohm noninductive "dry" dummy load:

http://www.n0ss.net/dl_30w_hf-uhf.pdf

Made from the heat sink for an old Slot 1 processor, a noninductive Caddock resistor (article gives Mouser part numbers), UHF or N connector and some bits of hardware. Less expensive than even an MFJ.

Not my idea, just passing it along. The creator simply gave the idea away on his website.

Dress it up a little with a sheet metal cover over the resistor for that "PROFESSIONAL" look.....

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
The creator simply gave the idea away on his website.

----------------------------

Using Caddocks in this way is standard practice and has been for several years, even predating this pdf.

Thermal conductive goop is needed and Caddocks do change impedance with higher thermal loading--before they burn out. It's a good product. Use it as spec'ed.

Be sure that all thermal conductive surfaces are gooped as a bond.

Certainly the flea market availability of cheap computer- CPU heat sinks makes this a good ham project.

Don't run a KW into one....

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Be sure to use gloves when working with the white goop. It is a mess; I don't know about it's toxicity but best not to get on the skin, IMO.

The pressure plate on the Caddock (in N0SS's pdf) is used to assure the conductive interface has sufficient pressure to assure heat transfer. There are ones (Caddocks) with screw holes to also accomplish this. Also, the resistors don't do well if too much pressure is applied. Finally be sure to understand that the resistor IS NOT GROUNDED to the heat sinks and the pins should be bent up to discourage arcing. Be sure to secure the coax well to the pins, because they do get hot.

As with all RF devices, never run it beyond the spec's of the individual parts.

73,
Chip W1YW
 
Don't like to drill holes in new cars?  
by RADIOWEENIE on June 3, 2007 Mail this to a friend!
As far as I (myself) am concerned, I don't give a rat's refuse recepticle about drilling a hole or two in a new car. By the time i get rid of it, it will be over 3 years old, have 200K+ miles on it, and have an antenna hole or two in it anyway. But whenever we get a new car, i know the very first thing that will come out of my wife's mouth (and she is also a Ham!): "You're not going to drill any holes in that new car!" But I also know what will happen once the newness wears off in 6 months or so. I will then mention to her about installing a deuce in the car and she will say: "Well, that sounds like a good idea!" The way i handle that problem is to use the older car and when she wonders "where have you been" I reply "if you had radio in your car, you would know". Works for me!

RW
 
Don't like to drill holes in new cars?  
by RADIOWEENIE on June 3, 2007 Mail this to a friend!
As far as I (myself) am concerned, I don't give a rat's refuse recepticle about drilling a hole or two in a new car. By the time i get rid of it, it will be over 3 years old, have 200K+ miles on it, and have an antenna hole or two in it anyway. But whenever we get a new car, i know the very first thing that will come out of my wife's mouth (and she is also a Ham!): "You're not going to drill any holes in that new car!" But I also know what will happen once the newness wears off in 6 months or so. I will then mention to her about installing a deuce in the car and she will say: "Well, that sounds like a good idea!" The way i handle that problem is to use the older car and when she wonders "where have you been" I reply "if you had radio in your car, you would know". Works for me!

RW
 
Antenna Lessons from the Old Timers  
by K9IUQ on June 3, 2007 Mail this to a friend!
A great factual article, loved the picture as it looks like my tower......

This "ladder line is no good" vs "coax is better" along with "the antenna MUST be resonant to work" argruments has been beat to death in MANY threads on eham.

The newbies and hams that don't read antenna theory always go with coax.

Hams that have been around since Marconi and hams that read antenna books use ladder line on wire antennas...

Stan K9IUQ
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Hams that have been around since Marconi and hams that read antenna books use ladder line on wire antennas...

Stan K9IUQ

-------------------------

One cannot dispute this statement, as it most likely constitutes an empty set. IOW, who are the living hams who have been around since Marconi AND that read antenna books -- who use ladder line?

Marconi died 70 years ago. Let's assume there were 20+ year old hams at the time of Marconi's demise, who read antenna books and use ladder line.

This select group of hams is now 90+ years old.

Stan, can you kindly provide us a list of hams that meet your description?

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 3, 2007 Mail this to a friend!
Hams that have been around since Marconi

and hams that read antenna books use ladder line on wire antennas
.....................................................
Two separate kinds of hams. I forgot that one MUST be perfectly explicit on eham or someone will find fault with your statements.

The first statement "Hams that have been around since Marconi" was meant to be "tongue in cheek" (look up tongue in cheek in Wiki).) I forgot one NEEDS to be serious when talking antennas. :>

Stan K9IUQ
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 3, 2007 Mail this to a friend!
"Certainly the flea market availability of cheap computer- CPU heat sinks makes this a good ham project."

Yup. In fact, often complete computers are found discarded, reducing the heatsink price to zero. Some CPU heatsinks have integral fans, too.

If a heat sink and some hardware are on hand, the total project cost can be held to less than $10.

25-30 watts continuous, 100 watts for a couple of minutes at least. Or use the 100 watt Caddock resistor.

By comparison, the MFJ-260C ($40) is good for 25 watts continuous and 100 watts for 90 seconds. Or consider the MFJ-264 ($80), rated at 100 W for 10 minutes.

I'll take the homebrew option, thanks.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 3, 2007 Mail this to a friend!
"FAN DIPOLE

feed it any way you choose, it still works..

nuff said.."

Well, I'll say a bit more.

By "fan dipole", I presume that "parallel dipoles" is intended. Meaning one dipole for each band. Such as an 80 meter dipole in parallel with a 40 meter dipole, fed with a common transmission line.

And yes, such a setup does work well - equivalent to dipole for the band in use.

As for "feed it any way you choose", the whole point of such an antenna is so you can feed it with coax and have a low SWR on various bands. Maybe even do without a tuner.

If you're going to use open-line and a tuner, there's no real reason for the parallel elements.

Parallel dipoles have two major drawbacks, however:

1) They're mechanically complex, which also makes them more visible.

2) The dipoles all interact, making the adjustment procedure complicated.

Both problems get worse as bands are added. That doesn't mean the problem is unsolvable, but if you want to cover 80, 60, 40, 30, 20, 17, 15, 12 and 10 meters with a parallel dipole, better bring a big sack of time and patience.

73 de Jim, N2EY

 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 3, 2007 Mail this to a friend!
Parallel dipoles have two major drawbacks, however:

2) The dipoles all interact, making the adjustment procedure complicated.

......................................................

Yes they ALL interact and you could spend your whole ham career getting one to work right. Putting a parallel dipole will get you in shape tho, lots of exercise involved with this antenna which is why old timers never use one...

Put up a 130 ft wired fed with open wire feed line and with a tuner you are good to go on all bands 75-10 as soon as you can get outta the tree..

Stan K9IUQ
 
Antenna Lessons from the Old Timers  
by K9IUQ on June 3, 2007 Mail this to a friend!
N4KC says in his wonderful article on antenna lessons:

"We are enjoying an influx of newly licensed and newly privileged HF operators who might be able to benefit from a rational discussion on the subject."
..........................................................

K9IUQ says there never has been and never will be a *rational* discussion on antennas, feedline, resonance or CW among hams on eham.net

LMAO

Stan K9IUQ
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 3, 2007 Mail this to a friend!
"Parallel dipoles have two major drawbacks, however:

2) The dipoles all interact, making the adjustment procedure complicated.

......................................................

Yes they ALL interact and you could spend your whole ham career getting one to work right. Putting a parallel dipole will get you in shape tho, lots of exercise involved with this antenna which is why old timers never use one..."

Well, as an old timer, I wouldn't say 'never'. It all depends on how many bands you want to cover.

In my experience, two band coverage with a parallel dipole setup isn't too hard to adjust. Three bands is doable if you're patient. Beyond 4 or 5 bands, it becomes a matter of luck as well as patience.

"Put up a 130 ft wired fed with open wire feed line and with a tuner you are good to go on all bands 75-10 as soon as you can get outta the tree.."

Yup. And the 130 foot number isn't critical; you can go somewhat longer or shorter without a major effect on the performance.

With antenna modeling software, it's easy to figure out the approximate impedances at the antenna and shack-end of the feedline, so you know what the tuner is seeing.

One of the most common newbie mistakes is to try such a system with coax rather than ladder line. Such a system will appear to work, because the tuner will usually be able to find a match, and under the right conditions QSOs can be made with inefficient antennas. After all, the military uses the T2FD resistive-loaded folded dipole, even though it's much less efficient than a simple dipole of the same size.

If the SWR of a coax-fed antenna is considerable on certain bands, the total loss of the coax (matched-loss plus SWR loss) on those bands can be high. I posted typical figures for such a coax-fed system earlier in this thread.

Yet at least one newbie has recommended such a system, right here.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N9FE on June 3, 2007 Mail this to a friend!
Yes 130ft dipole 40ft off the ground fed with 600 ohm right to the johnson matchbox. 20 over s9 with 100 watts, 30 over s9 with 500 watts on the salt lake s-meter which is 1500 miles away from my QTH, any night of the week on the 80 meter band, OH thats right.. cowchippy doe's not know about no salt lakes nor s-meters..
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 3, 2007 Mail this to a friend!
It is absoultly amazing the arguements about antennas on here. I have never seen much difference with any type of antenna ,properly installed. The 130' wire fed with balanced lines works, altho I don't like using tuners, nor do I like open feed line in my shack. The FAN or Parallel Dipole works good, and it really isn't that hard to build, but does take patiences to tune. 4 wire will give you the 5 major bands, as the 40M wire will load on 15M. Trapped dipoles work very well also. People have it in their head that traps are bad, but that not necessarly true.
Properly designed traps work very well and have been used for years on commercial made beams and verticals.
Its very easy to build your own traps, that will handle legal limit. The OCF (off center fed) antennas, also sometimes called a Windom, also work very well on many bands. Buckmaster makes an OCF that is truely amazing in performance, and built like a tank! End fed 1/2 wavelength antennas work well also, providing you build a matching device to feed it with voltage, instead of current. They ALL will work just fine and one would probably never notice any difference from one to the other. Antenna height on HF isn't that critical either, unless you want as true an omnidirectional antenna as possible, then it needs to be @ least a 1/4wave off the ground.

These are all hardcore fact gentleman, so really its just a personal choice, or what will fit best in your situation & budget. Just remember when using open line, it is NOT as convient to work with as coax, and it has to have as little intervention from outside influences as possible, even weather can effect it. Good coax altho, a tad more loss than open line is as forgiving as hell, as long as you don't kink it.

So all of these arguements have been over personal choice of antenna, and not the design of the antenna.

Its like arguing over which is better, Kenwood, Icom or Yaesu? They are all ok, but none of them really work any better than the other! None of them are built with any true quality anymore. Its a matter of appearence, features and personal choice.

73 de W4LGH - ALan
http://www.w4lgh.com
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Yes they ALL interact and you could spend your whole ham career getting one to work right.
--------------------------------------------

That is correct. Since the longer(est) lines harmonically resonate at the higher bands you get issues with interaction. Same issue with multiband quads.

So, the trick is to break the harmonic/picket fence relation for the higher frequencies.

Where is it written that all dipoles must have picket fence, modulo-n harmonics. Think of this as a filter--a crappy one. How would you fix it?

73,
Chip W1YW
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
Yes 130ft dipole 40ft off the ground fed with 600 ohm right to the johnson matchbox. 20 over s9 with 100 watts, 30 over s9 with 500 watts on the salt lake s-meter which is 1500 miles away from my QTH, any night of the week on the 80 meter band, OH thats right.. cowchippy doe's not know about no salt lakes nor s-meters..

---------------------------------------

Can you TALK better than you WRITE (or should I say 'type')?
 
Antenna Lessons from the Old Timers  
by W1YW on June 3, 2007 Mail this to a friend!
We are enjoying an influx of newly licensed and newly privileged HF operators who might be able to benefit from a rational discussion on the subject."

------------------------------------------

Not quite true. The number of upgrades has dramatically increased-- but the huge number of expected new hams has NOT materialized...and the overall number of licensed Part 97 'hams' continues to decline.

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 3, 2007 Mail this to a friend!
"The number of upgrades has dramatically increased--"

That's true.

"but the huge number of expected new hams has NOT materialized...and the overall number of licensed Part 97 'hams' continues to decline."

Not according to the FCC database.

The number of FCC amateur licenses held by individuals had been declining from mid-2003 until this past February 23. But since Feb 23, 2007, the decline has stopped and there has been a slight increase.

73 de Jim, N2EY


 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 3, 2007 Mail this to a friend!
"Think of this as a filter--a crappy one. How would you fix it? "

I want my antennas to act as filters... not crappy ones, but I want reduced response outside of the ham bands.

Dan
 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 3, 2007 Mail this to a friend!
Another thing about feeding with open wire line is you can model and optimize an antenna for your application with less regard for a pre-determined feedpoint impedance.

I adjusted my 20m wire quad for best forward gain with less regard to F/B ratio because it's fixed-direction (SE) and actually works very well off the backside to the NE. Plus, my element spacing 'is what it is' due to it being on the same set of two ropes as other antennas.

So, I diddled for what I wanted and ended up with 110 Ohm feedpoint Z. Sure I could have used a quarter-wave transmission line transformer using 75 Ohm coax (and in fact I do this w/ my FD version of this antenna to simplify it's use and I can use lightweight RG8X) but instead I don't have to worry about it.

Interesting article about this:
http://users.triconet.org/wesandlinda/ladder_line.pdf

Look at the higher loss on windowed ladder line when WET. Note these tests were at 50MHz, probably to emphasis worst-case. This is why I changed to my own homebrew open wire line and I now use the ladder line for field day antennas since it (so far) never rains on FD, even here in Seattle.

I have a backup FD antenna that's a coax-fed 40m dipole with these little 'bowtie' wires at critical spots (one per leg) that tames the tuning on 15m so it has a really usable VSWR on the low part of 15m. I can't find the article right now, but I can if someone is interested.
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 3, 2007 Mail this to a friend!
N4KC says in his wonderful article on antenna lessons:

"We are enjoying an influx of newly licensed and newly privileged HF operators who might be able to

benefit from a rational discussion on the subject."
.........................................................

K9IUQ says there never has been and never will be a *rational* discussion on antennas, feedline,
resonance or CW among hams on eham.net

LMAO

Stan K9IUQ
.........................................................

Gotta agree with you, Stan. :-)

Come to think of it, maybe all these postings - composted - would help hurry up growing two tall
evergreens at my QTH? They are seedlings from cones fallen in Washington state. Gots to have them 40 to 50 feet high to hold that absolutely-necessary horizontal dipole whatever or my signal "never gets
out!" Oh, woe...hurry...hurry...grow...grow... :-)

73, Len AF6AY [born and raised in Rockford upstate]
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 3, 2007 Mail this to a friend!
"We are enjoying an influx of newly licensed and newly privileged HF operators who might be able to benefit from a rational discussion on the subject."

------------------------------------------

W1YW: "Not quite true. The number of upgrades has dramatically increased-- but the huge number of expected new hams has NOT materialized...and the overall number of licensed Part 97 'hams' continues to decline."

As one who took all the tests on 25 February 2007 (and passed them all), I've been keeping track of the license number statistics courtesy of www.hamdata.com on a daily basis. Comparing today (3 June) with (very roughly) three months ago of 4 March, the total licensee numbers, exclusive of club calls, went from 711,063 on March 4 to 711,562 on June 3. That's a total licensee increase of 0.070% and so small it could be a random blip. You are correct.

The end result rather clearly shows that the supposed, claimed, warned-about blabbing by olde-tymers of "hordes of CB-ers [and other unmentionables]" just NEVER showed up. The increase in newcomers is only slightly offsetting the continuing expirations that have been going on for four years. I've posted slightly more detailed numbers on 30, 60, and 90 day intervals on rec.radio.amateur.moderated newsgroup if anyone is interested. I also have ZIPs of daily downloads from www.hamdata.com that I can forward by e-mail attachment to the hardcore confrontational argumentor-inquisitors who don't like such news. :-)

However, W4LGH and K9IUQ pretty well hit the nail on the thumb with their recent postings. I suspect that Don Keith was thinking more of igniting some controversy with his original article posting...which it did successfully. :-)

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 3, 2007 Mail this to a friend!
"Look at the higher loss on windowed ladder line when WET. Note these tests were at 50MHz, probably to emphasis worst-case. This is why I changed to my own homebrew open wire line and I now use the ladder line for field day antennas since it (so far) never rains on FD, even here in Seattle."

Good points!

But note also how true ladder line (the last row on the table in the paper) had the lowest loss and was unaffected by being wet.

IMHO, we hams should use the following terms and definitions:

"Ladder line" and "open wire line" refer only to balanced lines with spreaders, like the line shown in the original article of this thread.

"Window line" refers to the "Twin Lead with holes" stuff such as sold by Wireman.

"Twin Lead" refers to balanced line with the wires imbedded in continuous insulation.

IMHO

73 de Jim, N2EY


 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 4, 2007 Mail this to a friend!
"Its like arguing over which is better, Kenwood, Icom or Yaesu? They are all ok, but none of them really work any better than the other! None of them are built with any true quality anymore."

OTOH, if you want a rig that *is* better, there's TenTec and Elecraft.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 4, 2007 Mail this to a friend!
Maybe the licence structure should be graded according to the number and quality of knobs on the equipment - for example a novice would only be allowed a power switch and a plain black tuning knob, whereas an Extra would have a roofing filter with a brushed aluminum knob. This would mean of course that the novice would work more DX, but that would not matter, because the Extra would have more bragging potential.
Buffalo Gil
 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 4, 2007 Mail this to a friend!
Gil, when roofing filters with a brushed aluminum knob are outlawed, only outlaws will have roofing filters with a brushed aluminum knob!
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 4, 2007 Mail this to a friend!
I am working-class from England, but now fortunately live in America. In England we often say 'We are going to mix with the big knobs' - meaning we are going to perhaps a party where aristocrats will be present.
Do you use this expression in America?
Gil
 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 4, 2007 Mail this to a friend!
Having never been to a party with aristocrats present, I can't really say but I've never heard that expression used in the USA. Actually, 'big knobs' means in rough slang something completely different and you probably don't want to say it at a party.

We call the upper level management of a company "Big Wigs" but it's not a term of respect. Other management is sometimes referred to as "suits" because in a lot of companies they are the ONLY people wearing dress clothes such as suits.

Here in WA state, suits and ties are worn to funerals and court hearings, that's about it.
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 4, 2007 Mail this to a friend!
"Maybe the licence structure should be graded according to the number and quality of knobs on the equipment - for example a novice would only be allowed a power switch and a plain black tuning knob, whereas an Extra would have a roofing filter with a brushed aluminum knob."

What about a station like this:

http://hometown.aol.com/n2ey/myhomepage/

26 knobs and 10 toggle switches. Three meters, too.


73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by KD6SZB on June 4, 2007 Mail this to a friend!
I'm not an antenna/feed line engineer, but it would seem most people here, 90%, should sit down beside the fire with a copy of Reflections or Reflections II by Walter Maxwell. It'll open your eyes, in the first chapter alone. It does have a lot of obscure math, but the author does such a good job you can skip over all but the simplest arithmetic and get what he's talking about perfectly.

In short, VSWR is irrelevant to antenna performance. Want proof? Okay, where does the reflected signal go? Back to the finals as heat? No, there's a tuned circuit in the way. Does it get used up as heat? No, if it did, my RG8X would have burned up long ago at a 6:1 VSWR on some frequencies. Does it just bounce back and forth forever between the "faulty" antenna and the output stages tuning circuit, until it is mercifully released when one end is removed? You know the answer to that. No. I'll let you off the hook; it goes out the antenna, all but at most 1Db of it at HF. And 1 Db is not that much. Remember, when it comes to "Where does the reflected signal go?", the answer is always "no", unless it's "Out the antenna". As a matter of fact, the only place reflections are detrimental are fast-scan analog image transmitting and multiplex systems. So, if you’re not using fast scan TV or a multiplex system on HF, which you really shouldn’t anyway, feed line reflections are not an issue. As further proof, here's some basic math concerning the subject of feedline reflections:

100W up an RG8X 200Ft run to an 80M dipole/Inv "V" w/ 2:1 SWR (mine).

First pass, about .02db is used up and about 10% are "bounced". How sad, we just lost 10%, right? No, the answer is always “no“.

Second pass after bouncing off the finals output network, .04Db is lost off of the 10 watts that was sent back to the transmitter during the round trip and 10% of the energy bounced back the second time.

That means by just the second trip, about 98% of the energy left the antenna successfully.

So, what burns up final output stages in a high VSWR system? VSWR? No, an improper load does, nothing else. What does affect antenna performance? That would be the ground system, height, DC resistance in elements and matching sections and the quality of electrical connections. No, I did not forget VSWR, because it doesn't. It only tells you how well the antenna is matched to the feed line.

How about another example? You've got an 80M 1/4 wave Marconi on coax and a vacuum tube output. You put down about 100 radials, resonate the antenna and, uh-oh, you've got a 1.5:1 VSWR. What do you do?

A. Live with it. That SWR is not important and the transmitter tunes out the 3:1 or more on each end of the band with no problem. At least a Kenwood TS-820S does.

B. Hitch it up to your transmatch and make it work.

C. Remove radials until that sucker is at a smokin' 1:1.

If you chose C, log onto the FCC website, cancel your amateur radio license, sell your equipment, bank most of the money and use the rest for a nice CB radio set and an Antron 99.

If you chose B, go buy Maxwell's book and this time read it, unless you're using solid state finals, in this case only use the transmatch when the VSWR goes above the point where the radio starts dropping its output. They do have a bypass switch.

If you chose A, you read my description and know that I'm talking about vacuum tube finals and that VSWR is not important if you can tune it out. AND, if you use a transmatch in this situation you're wasting valuable transmit and receive energy within it.

Baluns. Oh for crying-out-loud! You do NOT get RF in the shack if you use coax to feed a dipole. If your shield is grounded via a bulkhead connector or better yet a lightning arrester before entry, which it should be, and your equipment is properly grounded, which it should be, forget about it. And it won't lower your antenna efficiency, either. And I'll tell you something else, if you're so worried about the pattern of your antenna being distorted after spending a whopping $10 on a wire dipole or similar, less the feed line and supports, you need to re-evaluate your priorities.

It comes down to this; the reason they used ladder line in the first place was because that's all they had. Except for unusually long runs and matching sections, which it works well in, there is no use for it.

That's it, go forth and read Reflections.
 
Antenna Lessons from the Old Timers  
by W1YW on June 4, 2007 Mail this to a friend!
It comes down to this; the reason they used ladder line in the first place was because that's all they had.

-----------------------------------------
Yes.

Careful, the next thing you know a bunch of irate hams will be wishing you were dead and trying to destroy your reputation...

;-)
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 5, 2007 Mail this to a friend!
So - I have built a 5 band boomless quad and I feed it with ladder line through a Matchbox. It comes up to simulated spec and has a symmetrical pattern.
How could I feed it with coax without introducing baluns or chokes please?
(N2EY I like your station all homebrew very nice)
 
Antenna Lessons from the Old Timers  
by W1YW on June 5, 2007 Mail this to a friend!
This is a stupid question. Newbies are going to think the default way to feed a quad is with LADDER LINE...

Hey OM--I've got news for you...93 ohm coax has a far closer characteristic impedance than any ladder line you ever used.

As to your question. Well, THINK. How would you change the lengths and placement of the elements so that the DRIVE IMPEDANCE decreases to 50 ohms--but the elements remain resonant at the desired bands?

No 'parts' now...

As per using ladder line on a ROTATABLE QUAD...gimme a break!

 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 5, 2007 Mail this to a friend!
>This is a stupid question.>
Thank you

>93 ohm coax has a far closer characteristic impedance than any ladder line you ever used.>
Closer to what?

> Well, THINK. How would you change the lengths and placement of the elements so that the DRIVE IMPEDANCE decreases to 50 ohms--but the elements remain resonant at the desired bands? >
I have THOUGHT now - the spider quad is designed to have optimum spacing on all bands, so I wouldn't like to alter that. I could alter the lengths of course but this would degrade the f/b or forward gain - I wouldn't like that.
How would I get rid of RF down the braid without baluns or chokes? My line is truly balanced so it does not radiate or spoil the symmetry of the main lobe.

>As per using ladder line on a ROTATABLE QUAD...gimme a break! >
I wish we could.
It only has to rotate 360 degrees no more.

The quad is an ideal project for a newbie, more educational than buying a SteppIR - particularly a monoband quad as a prototype, on 10m when the band is open.

Gil W2/G3LBS
 
Antenna Lessons from the Old Timers  
by W1YW on June 5, 2007 Mail this to a friend!
could alter the lengths of course but this would degrade the f/b or forward gain - I wouldn't like that.
How would I get rid of RF down the braid without baluns or chokes? My line is truly balanced so it does not radiate or spoil the symmetry of the main lobe.
--------------------------

You are not THINKING. Many efforts to make to match 50 ohms can be found to have minimal impact on the gain and F/B.

Why would you have RF coming down the coax? Why do you ASSUME that would be a preferred path?

Why do you assume that you DON'T have RF coming down your ladder line?

Give us links and show us a picture of your salt water dummy load and rotatable 5 band quad fed by ladder line.

Is it also made of bamboo spreaders? Do you use a flourescent bulb to tune for max power?

Do some of your recommendations come from the IMPOVERISHED RADIO EXPERIMENTER?

If you are speaking from experience then prove it Ol' Boy.

Stiff upper lip that!

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 5, 2007 Mail this to a friend!
"So - I have built a 5 band boomless quad and I feed it with ladder line through a Matchbox. It comes up to simulated spec and has a symmetrical pattern.
How could I feed it with coax without introducing baluns or chokes please?"

First way:

Put a remote-controlled balanced tuner right at the feedpoint. Run coax and tuner-control cable from the tuner to the shack. The whole shebang only has to cover a 2:1 frequency range (20 to 10 meters), and the impedances don't get too high.


Second way:

Gamma-match each loop. (assuming there are separate loops for each band). Use a relay switch box to select the right one.


Third way:

Use two pieces of coax back-to-back in a balanced 100 ohm configuration. (Loop Z needs to be near 100 ohms and not very reactive for this to work).


Fourth way:

Link-couple the coax to each loop. Use a relay switch box to select the right one.


Of course none of these are as easy, quick, inexpensive or lightweight as just using ladder line.

But you did ask the question.

"(N2EY I like your station all homebrew very nice)"

Thank you. I like it and it does the job very well. Didn't cost me much, either - some folks pay more for one optional filter than I paid for all the parts in the rig. Lots of reused surplus (swords into plowshares) and hamfest finds made that possible.

Of course it's electro-politically incorrect to some folks.

73 de Jim, N2EY

 
RE: Antenna Lessons from the Old Timers  
by W0IVJ on June 5, 2007 Mail this to a friend!
KD6SZB said:

"100W up an RG8X 200Ft run to an 80M dipole/Inv "V" w/ 2:1 SWR (mine).
First pass, about .02db is used up and about 10% are "bounced". How sad, we just lost 10%, right? No, the answer is always “no“. "

Where do you find RG8X with a 0.02db matched loss for 200 feet not including the additional loss due to the 2:1 SWR?

Tom W0IVJ
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 5, 2007 Mail this to a friend!
"100W up an RG8X 200Ft run to an 80M dipole/Inv "V" w/ 2:1 SWR (mine).

First pass, about .02db is used up and about 10% are "bounced". How sad, we just lost 10%, right? No, the answer is always “no“."

More noes than you think.

At 3.5 MHz, 200 feet of Belden 9258 has a matched loss of 1.047 dB, according to

http://www.ocarc.ca/coax.htm

That's when the coax is new.

BTW, when you say "2:1 SWR", is that at the load end or at the shack end? Loss in a transmission line will make the SWR look better than it really is. For example, a line with 2 dB of matched loss and an SWR of 3:1 at the load end will have less than 2:1 SWR at the feed end.

In fact, a line with only 5 dB of matched loss can be open or shorted at the far end (infinite load-end SWR) and the feed end SWR will never exceed 2:1.

"Second pass after bouncing off the finals output network, .04Db is lost off of the 10 watts that was sent back to the transmitter during the round trip and 10% of the energy bounced back the second time.

That means by just the second trip, about 98% of the energy left the antenna successfully"

No, it doesn't.

The additional loss due to the 2:1 SWR in the above case is .203 dB. So the total loss is 1.25 dB.

That's not bad at all. But it's not 98%, either.

There are several more mistakes and over-generalizations in your post, but I'm out of time right now.

So I'll just say this:

All antenna systems involve tradeoffs.

The only rational way to decide what tradeoffs to accept is to look at the entire antenna/transmission line *system* as a whole. This isn't hard with a few software tools and some knowledge of what's really going on.

Coax, ladder line, tuners of all flavors, baluns, ununs, stubs, matching sections, traps, SWR indicators, and various forms of analyzers all have their place in the HF ham's antenna toolbox. None of them is magic nor a cure-all.

The trick is knowing which tool to use for which job.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 6, 2007 Mail this to a friend!
"There are several more mistakes and over-generalizations in your post, but I'm out of time right now. "

There are omissions too, like the 60:1 SWR you get when you feed your 80m dipole on 40m without doing something to match it at the antenna.

6:1 SWR on coax... no big deal. 60:1 SWR on coax... mismatch loss through the roof.

We've been through it all already, but still a few more articles before this one drops of the front page, so let's keep it going! Can we make it all the way around again?

Dan
 
RE: Antenna Lessons from the Old Timers  
by W0IVJ on June 6, 2007 Mail this to a friend!
Dan N3OX said:

"We've been through it all already, but still a few more articles before this one drops of the front page, so let's keep it going! Can we make it all the way around again? "

In that spirit, I would like to offer up the following suggestion. One of the best ways to get a feel for antenna systems and losses is to use some excellent computer tools that are available. If you download EZNEC from http://www.eznec.com you can model your antenna and get its feed point impedance. The free version is limited, but it will work for simple antennas. Then take that feedpoint impedance and plug it into TLW which is on the CD that comes with recent copies of the ARRTL Antenna Handbook. If you can't get TLW, use the feedline calculator at http://www.ocarc.ca/coax.htm and calculate the SWR and loss at the feedline length and frequency of interest. If you use TLW, you can even go through a tuner and calculate the tuner losses. These tools give you a very nice systems approach to antenna design. Granted, they are just models, but they will get you in the ballpark and give you a feel for various situations because you can design so many systems in such a short time. With EZNEC you can even see whether or not a balun is required.

73 Tom W0IVJ
 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 6, 2007 Mail this to a friend!
Tom, how do I use EZNEC to see if a balun is required? I Have NEC-Win Plus personally and please note I'm not a troll this is a real question.

Thanks,
N4SL

http://www.nittany-scientific.com/
 
RE: Antenna Lessons from the Old Timers  
by W0IVJ on June 6, 2007 Mail this to a friend!
N4SL said:

"Tom, how do I use EZNEC to see if a balun is required? I Have NEC-Win Plus personally and please note I'm not a troll this is a real question.

Thanks,
N4SL"

N4SL,

Look in the EZNEC help file Contents under Transmission Lines and then under Coaxial Cable. The second sentence talks about a radiating coaxial cable. Follow the instructions. I discuss this in my Eham article published on May 20, 2007 found at:
http://www.eham.net/articles/16644
There are further references in the article.

73 Tom W0IVJ
 
RE: Antenna Lessons from the Old Timers  
by WB9UAI on June 7, 2007 Mail this to a friend!
Here's my 'secret' DX antenna: a 40 meter full wave loop, fed on one side with open wire feeders (window line). It also works well on 80 meters too as a top loaded vertical. Hello DX !

John K9RZZ
Milwaukee, WI
 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 7, 2007 Mail this to a friend!
WB9UAI > Here's my 'secret' DX antenna: a 40 meter full wave loop, fed on one side with open wire feeders (window line). It also works well on 80 meters too as a top loaded vertical. Hello DX !
..................................................

Here is something the coax lovers don't want you to know

I put up a "SKY WIRE" antenna described in the ARRL antenna handbook a few years ago. This is a 277 ft loop supposed to work 80-10 mtrs like gangbusters. Fed with coax. Didn't work for me with coax. Had lots of trouble on 40 mtrs. So ---- I took the coax off and fed it with 600 ohm open feedline. Guess what, NOW it works like gangbusters. Probably the best antenna I have ever used for 80 and 40 mtrs.

Coax is fine for a SINGLE band BUT when you want one WIRE antenna for 2 or more bands Open feeders cant not be beat.

Stan K9IUQ
 
RE: Antenna Lessons from the Old Timers  
by KD6SZB on June 7, 2007 Mail this to a friend!
Okay, for crying-out-loud. I'll revise the loss characteristics of RG8X, .4Db per 200 feet on 80M. Did anyone who nitpicked this point also point out that at a 2:1 VSWR at a loss of .4Db on the incident wave and a total of .8 db off of the reflected wave on the first trip alone was STILL less than 1DB total loss? No, as usual, all that most people can seem to do when confronted with common sense and hard science is pick at something irrelevant to the discussion. The real point was that VSWR in a feed line with a resonant antenna SYSTEM... is irrelevant.

And, I seem to remember saying a VSWR of 6:1, not 60:1. If you've got 60:1, your problem is not a non-resonant antenna or a mismatched feed line. You need to put the right antenna connector in the right jack, or, if that's not the cause, learn at least the most basic fundamentals of antenna engineering.

The fact is, when I first put up my inverted V I didn't bother checking the VSWR because I knew the feed point connection was secure, the feed line was in good shape and each leg of the dipole was 1/4 wave. I knew they'd come up long being only 20' off the ground at the apex, but I also knew that my TS-820S would also be able to tune out a VSWR that this setup would produce. After a while, and when I got some spare time, I went ahead and pruned the antenna to resonate on 3.8Mhz. All that happened was the Kenwood was a little easier to tune and my VSWR went down to 1.5 or less from about 6:1. Yes, I also acknowledge that it was not a "resonant" antenna, but it was so close that even with a "dreaded" VSWR of 6:1, the performance increase due to pruning, if there at all, was, again, irrelevant. All I got out of it was an easier to tune transmitter, which is what I was after in the first place. Oh, that's with 200 feet of RG8X, too.

The next point, regarding baluns: I said, and I quote, "If you spent $10 on a dipole antenna minus the supports and feed line and you're worried about a distorted antenna pattern, your priorities are in the wrong place". Where in there did you see directional array, rombic, sturba curtain, ground plane or anything else for that matter? The key point here is being all atwitter over the radiation pattern of a $10 80M dipole wire antenna. Sorry, I'm not going to wind 20+ feet of coax into a nice neat coil or try to find a huge ferrite toroid to wind it around just to make my Inverted V, that's only 20' off the ground in the first place, radiate a nice, perfect Figure 8 pattern. I've got far more important priorities right now.

A suggestion: Stop nitpicking and get down to the real issue. "The loss due to VSWR in coaxial cable at HF in general and low band HF in particular is not important. And, going to the trouble to run open line feeder with all the added support components, impedance matching baluns, standoff insulators, transmatch, et al for a teeny-tiny increase of a Decibel or so is at best a waste of time, and worst, a waste of money. Most likely, the loss with all that extra "Stuff" will be higher than just using good quality coax. As an added benefit, you won't have to "pamper" and "Baby-sit" open line feeder. Save the ladder line for long, very long runs in relation to frequency, Zeps, Beverage antennas and matching sections.

All I was trying to point out is, the fictional character in the story-article had other issues rather than VSWR loss in a 100 or so foot run of RG8X at 80M, big issues. Because I sure don't have those problems with the same antenna at a lower height and longer feed line run.

And one more thing. Unless it was "Tongue-in-Cheek", to the guy who said that as an amateur radio operator it is, "Our duty to move to a location that will allow us to erect an appropriate antenna system/s", I invite you to read this link:

http://www.arrl.org/acode.html

Pay particular attention to item #5. When one says "Working with low band HF antennas involves trade-offs and compromise", that involves things totally unrelated to the antenna system itself.
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 7, 2007 Mail this to a friend!
KD6SZB says:

". If you've got 60:1, your problem is not a non-resonant antenna or a mismatched feed line. You need to put the right antenna connector in the right jack, or, if that's not the cause, learn at least the most basic fundamentals of antenna engineering. "

People like to use their 80m dipole on 40m.

The SWR could easily hit 60:1 there.

Don't try to distill W2DU's work into a sentence or two... that does a good monograph a disservice.

SWR is NOT irrelevant to HF antenna systems. Nor is it of primary importance.

However, many antenna tuners will allow a match when attached to the shack end of a 100 foot run of RG-8X feeding a 1 wavelength doublet. Many hams take that to mean the antenna system "works on that frequency". What's the SWR if you feed a 1 wavelength doublet with 50 ohm or 75 ohm coax?

*THAT* is the issue. The way you put it, it makes it seem like you can directly feed any old doublet with any old piece of coax and NEVER worry about elevated-SWR line loss, and that is just plain wrong.

If you cut your antenna to a more-or-less half wavelength and put it up, it will work well... even with 5:1 or 6:1 SWR, I'll grant that. If everyone would only operate their antenna on frequencies where the SWR on 50-ohm line was less than 6:1, they would see modest losses. But that's not what people do.

They consider their antenna to "work" even with an SWR of 60:1, long runs of RG-8X, and 10dB of loss from line mismatch.

- - - - - -

Say what you want about the aesthetics or technical worth of a ladder-line fed doublet of random length greater than a half wavelength... but the truth is, it will radiate more of your power if you feed it with ladder line than if you feed it with coax.

Those with some other axe to grind have said a lot in this thread to obscure that fact, but it stands. You can find frequencies for which the loss will be trivially different between the two feedlines, but others where you will be 10dB stronger with ladder line.

I encourage everyone to learn on their own why this is, otherwise you're in danger of listening to some dude on the internet...

Dan
 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 7, 2007 Mail this to a friend!
Run a 6:1 VSWR on that coax and drive it w/ 1500W (even larger coax, big stuff) and what's the peak voltages? Oh Oh.
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 7, 2007 Mail this to a friend!
"I'll revise the loss characteristics of RG8X, .4Db per 200 feet on 80M."

Where does that number come from?

According to

http://www.ocarc.ca/coax.htm

the *matched* loss of 200 feet of RG8X the good Belden stuff) at 3.5 MHz is 1.047 dB, not 0.4 dB.

"Did anyone who nitpicked this point also point out that at a 2:1 VSWR at a loss of .4Db on the incident wave and a total of .8 db off of the reflected wave on the first trip alone was STILL less than 1DB total loss?"

Except it's not less than 1 dB loss - it's more!

"No, as usual, all that most people can seem to do when confronted with common sense and hard science is pick at something irrelevant to the discussion."

Your numbers simply don't agree with the published data.

"The real point was that VSWR in a feed line with a resonant antenna SYSTEM... is irrelevant."

The problem is that the SWR is *not* irrelevant at all, unless the matched feedline loss is so low that the additional SWR loss doesn't amount to much.

An 80 meter center-fed dipole will be resonant on 40 meters. But if you feed it with coax, the SWR on 50 meters will be enormous and the loss will be considerable.

"And, I seem to remember saying a VSWR of 6:1, not 60:1."

That's true. But where is that SWR measured?

If you measure SWR of 6:1 at the shack end of a line with 1 dB loss (200 feet of RG-8X, for example), the actual SWR *at the antenna* is 20:1. That's because the loss in the line makes the match seem better than it really is.

"If you've got 60:1, your problem is not a non-resonant antenna or a mismatched feed line. You need to put the right antenna connector in the right jack, or, if that's not the cause, learn at least the most basic fundamentals of antenna engineering."

Like the feedpoint impedance of a one-wavelength resonant antenna fed in the center.

"The fact is, when I first put up my inverted V I didn't bother checking the VSWR because I knew the feed point connection was secure, the feed line was in good shape and each leg of the dipole was 1/4 wave. I knew they'd come up long being only 20' off the ground at the apex, but I also knew that my TS-820S would also be able to tune out a VSWR that this setup would produce. After a while, and when I got some spare time, I went ahead and pruned the antenna to resonate on 3.8Mhz. All that happened was the Kenwood was a little easier to tune and my VSWR went down to 1.5 or less from about 6:1."

Your line loss also dropped quite a bit, too.

"Yes, I also acknowledge that it was not a "resonant" antenna, but it was so close that even with a "dreaded" VSWR of 6:1, the performance increase due to pruning, if there at all, was, again, irrelevant. All I got out of it was an easier to tune transmitter, which is what I was after in the first place. Oh, that's with 200 feet of RG8X, too."

http://www.ocarc.ca/coax.htm

tells a different story.

"The loss due to VSWR in coaxial cable at HF in general and low band HF in particular is not important."

That's simply not true as a general statement. Not true at all.

What *is* true is that the total loss in a coaxial cable feedline *CAN BE* of little importance if a bit of care is used in designing the antenna system.

"And, going to the trouble to run open line feeder with all the added support components, impedance matching baluns, standoff insulators, transmatch, et al for a teeny-tiny increase of a Decibel or so is at best a waste of time, and worst, a waste of money. Most likely, the loss with all that extra "Stuff" will be higher than just using good quality coax."

For the case where the feedpoint impedance allows the use of coax with moderate SWR, that's true.

But for the case where you want to cover many HF bands and the feedpoint impedances are all over the place, it's not true at all.

How much loss does the feedline have to present before you consider it significant? 3 dB? 6 dB? 10 dB?

"As an added benefit, you won't have to "pamper" and "Baby-sit" open line feeder."

Actually, I have found that coax requires more careful treatment than open line.

"All I was trying to point out is, the fictional character in the story-article had other issues rather than VSWR loss in a 100 or so foot run of RG8X at 80M, big issues. Because I sure don't have those problems with the same antenna at a lower height and longer feed line run."

Have you actually measured or calculated the loss of 200 feet of RG-8X at 3.8 MHz?

Here's that URL again:

http://www.ocarc.ca/coax.htm

The fact that you got one particular antenna to work OK for you doesn't mean the whole issue is overblown. Your statements are simply too general.

One of the most common newbie mistakes I see with wire antennas is the use of coax feedlines with mismatched loads. Like the ham who didn't have room for an 80 meter dipole, so he put up a 40 meter dipole, fed it with coax, and used a tuner to get it to load on 80 and the other bands. Then he wonders why he can't seem to work anybody on bands other than 40 and 15.

Can you see how overly-general statements like

"The loss due to VSWR in coaxial cable at HF in general and low band HF in particular is not important."

could be very misleading?

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 8, 2007 Mail this to a friend!
Great analysis Jim N2EY

If any newbies live near me in Western New York, I have a prototype spider quad I built from Aluminum strip from local hardware store, and some spare broken tridetic fiberglass spreaders from a bigger quad I have made.
I used the material to prototype a 10 m spider quad and it worked well. Now I have built the 5 band spider quad I don't need them. The tridetic spiders could be cut to size for 10m.
If any NEW ham wants these they are free for the collection. If not you are always welcome to visit my humble station. Bring your helmet.
Gil W2/G3LBS
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 8, 2007 Mail this to a friend!
"Great analysis Jim N2EY"

Thanks, but that was all basic stuff.

For a more complex HF antenna, check out:

http://tinyurl.com/323pmr

Click on the "next" link, which actually reads

"the next page of this foto-razdela",

for more interesting information about the Russian
Woodpecker.

73 de Jim, N2EY

...remembering Palmyra, NY....

 
Antenna Lessons from the Old Timers  
by KL7AJ on June 8, 2007 Mail this to a friend!
Excellent article:

It should be noted, for the still-skeptical, that there isn't a single AM broadcast antenna out of 1000 (if that many) that is actually self resonant....or even close. A.M. towers come in twenty-foot sections (in some case 60 foot sections). If an A.M. tower comes within 20 feet of being resonant, you're REAL lucky.

ALL...I repeat ALL A.M. broadcast antennas are considered to be non resonant. Standard practice for the past 60 years has been to put an antenna tuning unit at the base of a broadcast tower.

A.M. antennas are inherently VERY efficient....you cannot get an FCC license without PROVING at least 95% efficiency...with a little fudge factor allowed for directional arrays.

In fact the FCC regulations only specify antenna RESISTANCE....the reactance doesn't even figure on the license. It's assumed you will take care of that in the most efficient means possible...i.e. the standard ATU.

Eric
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 10, 2007 Mail this to a friend!
KL7AJ says..."ALL...I repeat ALL A.M. broadcast antennas are considered to be non resonant. Standard practice for the past 60 years has been to put an antenna tuning unit at the base of a broadcast tower."

This simply is NOT true anymore. About 85% of the AM broadcast antennas are NOW RESONANT! A company came out with a new type of AM antenna, which is no more thana wire that is spaced about 18" off the tower and will span up and down both sides of the town, and in some cases on the lower frequencies, it will span 4 sides of the tower to reach resonant length! This now gives the AM broadcaster the same advantages of having a resonant antenna just like the FM, TV and other commercial broadcasters! Resonance, meaning that the antenna length is that or a multiple length of the actual rf wavelength, not just when the reactance and resistance equal and cancel.

You also noted in your statement that the TUNER was at the base of the tower. This is correct, as putting the tuner at the back of the transmitter and feeding the tower with 50ohm coax simply would NOT work. The tuning or matching device was placed at the antenna, where it WOULD tune the reactance and resistance to equal, therefore making the antenna to appear electrically resonant. You can always make an antenna electrically resonant by having the matching unit at the antenna, but NOT at the other end of the coax!! And commercial antennas are fed with coax and not open line! An electrically resonant antenna is good, but not as good as a mechanically resonant antenna, and never will be.

Hence the same thing applies to your amateur radio antenna. After all RF is RF. If you feed your 130' wire with open feedline and a matching device in your shack, the "Antenna System" starts at the matching device in your shack. So you can TUNE the reactance/resistance out to equal and cancel. The 130' number is used as it is MECHANICALLY RESONANT in the 80meter band, you then tune the antenna into being "ELECTRICALLY RESONANT" at other frequencies, but at a cost of effeciency, however small that may be. Now if you feed the same 130' with coax and a tuner in your shack, the "ANTENNA SYSTEM" starts at the antenna end of the coax, and your tuner in your shack is only tuning out the complex impedances found on this COAX and NOT the antenna! Hence you are only fooling your radio into thinking it is seeing a 50ohm load. Losses go thru the roof!! But ANY rf radiated is rf radiated, and someone will hear you. If you'd like further PROOF of this, do a simple test. Most modern radios today have an ATU built in, and the meter in the radio will show reflected power. Hook a good SWR bridge up to the back of your radio, pick a frequency and turn on your ATU. You will see the internal meter on the radio show no or very little reflected power, but then look at the external meter!! It is showing just about the same reflected power as your internal meter was before you turned on your ATU unit.

This is all simple fact gentlemen and will never change no matter how much one argues about it. Electrically Resonant will NEVER equal Mechanical Resonance. It can subsitute, at a loss.

StepIr figured this out, and designed an antenna that was both mechanically and electrically resonant, and you will not hear ANYONE saying that antenna is anything but incredible!

73 de W4LGH - Alan
http://www.w4lgh.com

 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 10, 2007 Mail this to a friend!
"It should be noted, for the still-skeptical, that there isn't a single AM broadcast antenna out of 1000 (if that many) that is actually self resonant....or even close. A.M. towers come in twenty-foot sections (in some case 60 foot sections). If an A.M. tower comes within 20 feet of being resonant, you're REAL lucky."

Well, let's do a little math.

AM BC antennas are all verticals, fed against a good ground plane. So we're talking 1/4 wave resonance.

At 560 kHz, that works out to a tower a bit over 400 feet tall. At 1700 kHz, only about 137 feet is required for resonance.

Seems to me that whether or not an AM BC transmitting antenna is resonant depends a lot on where in the band the station is.

"ALL...I repeat ALL A.M. broadcast antennas are considered to be non resonant."

By whom?

"Standard practice for the past 60 years has been to put an antenna tuning unit at the base of a broadcast tower."

Which brings the antenna *system* to resonance.

"A.M. antennas are inherently VERY efficient....you cannot get an FCC license without PROVING at least 95% efficiency...with a little fudge factor allowed for directional arrays."

They're efficient because they're designed to be efficient. Most of that design consists of having an effective ground screen in place, so that the ground losses are very small. The classic "~120 radials at least a quarter wave long" idea came from research for AM BC.

"In fact the FCC regulations only specify antenna RESISTANCE....the reactance doesn't even figure on the license. It's assumed you will take care of that in the most efficient means possible...i.e. the standard ATU."

It's not figured because it's irrelevant - the reactance has to be cancelled out in order for the system to work.

The reason for specifying the antenna resistance is so that power output could be monitored by means of an RF ammeter, rather than a wattmeter. Broadcasters are required to stay close to their allocated power level, because too little means reduced service and too much means interference - in theory, anyway.

The big thing to remember, though, is that AM BC stations don't QSY very often. The antenna and transmitter are tuned up on the frequency shown on the license and then left alone except for checks that they are still within operational parameters. Most HF amateur operation is completely different.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 10, 2007 Mail this to a friend!
"This is all simple fact gentlemen and will never change no matter how much one argues about it. Electrically Resonant will NEVER equal Mechanical Resonance. It can subsitute, at a loss. "

Here we go again.

False.
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 11, 2007 Mail this to a friend!
'StepIr figured this out, and designed an antenna that was both mechanically and electrically resonant, and you will not hear ANYONE saying that antenna is anything but incredible!'

Alan - W4GLH -but does the SteppIR have optimum spacing of elements as well as optimum lengths? The spider quad does and it's much cheaper.
Gil

 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 11, 2007 Mail this to a friend!
"Alan - W4GLH -but does the SteppIR have optimum spacing of elements as well as optimum lengths? The spider quad does and it's much cheaper. Gil"

Yes, and the lengths are mechanically adjusted into resonance for whatever frequency you use, therefore you have both, mechanical and electrical resonance.
The perfect match!

Since it is obivious that most do not understand mechanical & electrical resonance, and its differences... let see who wahts to argue over whether it is the VOLTAGE or CURRENT that does the radiating? We know that voltage is the factor that pushes current thru a wire. How about free space?

73 de W4LGH - Alan


 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 11, 2007 Mail this to a friend!
"but does the SteppIR have optimum spacing of elements as well as optimum lengths?"

The SteppIR beams have fixed element spacing. The element lengths are continuously variable, but not the element spacings.

Check out the website. SteppIR does a good job of clearly showing how their antennas work.

www.steppir.com

"The spider quad does and it's much cheaper."

The main advantage of the SteppIR approach, be it as a vertical, dipole, or beam, is that the element lengths are *continously* variable. SteppIR accepts mechanical complexity to achieve electrical simplicity.

Note too that a SteppIR requires a control cable and control box.

"Yes, and the lengths are mechanically adjusted into resonance for whatever frequency you use, therefore you have both, mechanical and electrical resonance."

'Mechanical resonance' has nothing to do with the electrical performance of the antenna.

If what is meant is that the antenna element(s) are electrically resonant at the operating frequency, the term to use is 'resonant element' or 'resonant antenna', not 'mechanical resonance'.

To use the term 'mechanical resonance' to mean that an antenna element is *electrically* resonant is misleading - and just plain wrong.


73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by G3LBS on June 11, 2007 Mail this to a friend!
Why can't extra motors be put on the SteppIR to optimize the spacing on each band, since it must now be a compromise on a multibander, unlike the spider quad.
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 11, 2007 Mail this to a friend!
"Why can't extra motors be put on the SteppIR to optimize the spacing on each band, since it must now be a compromise on a multibander, unlike the spider quad."

The main problem with that is the mechanical complexity of moving elements that are over thirty feet long.

The SteppIR elements are hollow fiberglass tubing with a copper tape inside. The copper tape is wound and unwound by a stepper motor at each element. The mechanical strength is all in the fiberglass tubing.

Since the antenna is only covering a 2:1 frequency range, the compromise isn't too bad. If the elements are spaced 0.1 wavelength on 20 meters, they're 0.2 on 10 meters. Wide spacing on 20 requires a pretty long boom.

The spider quad, aka the boomless quad, is a classic case of an ingenious development serving several purposes at once. Instead of having a boom-to-mast bracket, boom, and two boom-to-spreader assemblies, with all their hardware, you just have the spider assembly and spreaders that are a little bit longer.

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by N4SL on June 11, 2007 Mail this to a friend!
I have modeled the StepIR HF yagi w/ it's fixed element spacing and really there is very little compromise.

Sure, a true monobander is a little better but if you've only got ONE tower...

I am also a quad fan and have built and tuned a bunch of them for fun.

This may be old news to everyone, but the ideal way to install a quad is to put up the reflector first and tune it to be resonant at the very bottom of the band in question. Then install the DE and of course complete the REF's closed loop and trim the DE length for the VSWR curve predicted when you modeled it. Right there, you have a good working quad. Sure, you can tune it up from this point, but if you are hanging a quad from tall trees at FD, this technique lets you build the quad on-site and i's fun.

Fun. Remember fun?
 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 11, 2007 Mail this to a friend!
'StepIr figured this out, and designed an antenna that was both mechanically and electrically resonant, and you will not hear ANYONE saying that antenna is anything but incredible!'
........................................................

Anyone that spends upwards of $1600 for an antenna is NOT going to say anything bad about. I have noticed that Steppir owners have Big Ego's, it also attracts the "Resonant has got to be Better crowd".

Alas it is just a Yagi, nothing more as far as performance goes. Don't believe me? Go look at the gain figures on the Steppir website. Steppir Owners WANT to believe it is magical because it is always resonant. Many other antennas perform just as well and at a much lower price.

I have a nearby friend who owns one. When he first got it he wanted a shoot out with me against my Log Periodic.He JUST had to prove that spending $1600 was going to give him a bigger signal than me. It didnt happen...........

Stan K9IUQ


 
RE: Antenna Lessons from the Old Timers  
by WA4DOU on June 11, 2007 Mail this to a friend!
"This may be old news to everyone, but the ideal way to install a quad is to put up the reflector first and tune it to be resonant at the very bottom of the band in question. Then install the DE and of course complete the REF's closed loop and trim the DE length for the VSWR curve predicted when you modeled it. Right there, you have a good working quad."

Quads are usually tuned for maximum f/b in the frequency range of interest, by tuning the reflector.
 
Antenna Lessons from the Old Timers  
by K6LHA on June 11, 2007 Mail this to a friend!
Before you guys resonate yourselves into building collapse, let me
ask a question about such "resonant" antennas as the Discone,
Log-Periodic, and the rhombic. If all "good" antennas have to be
resonant, why do those I mentioned work so well?

The rhombic is typically made of wire. A Log-Periodic can be done
that way but most use tubular pipe conductors and are rotatable.
The discone is supposed to be made of two conductive sheets but the
practical ones replace the metal sheets with tubular radials, thus close
to being "wires." What would a rhombic, log-periodic, or discone
resonance frequency be?

"Resonant" wire antennas have a low percentage bandwidth. An RCA
Turnstyle for channel 2 has a geometric center frequency of 56.921 MHz
but its bandwidth is greater than 6 MHz or 10.54% of geometric center
frequency. Obviously that one works fine in broadcast service. But just
what is its "resonant" frequency?

Does that mean that "resonant" wire antennas only work good in
amateur radio service? How do the electrons, fields and waves know
which service is using what? :-)

Making fat-out statements about "resonance is necessary" needs be
tempered a bit with harsh reality on non-resonant antennas actually
working just fine and very large percentage bandwidths..
 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 11, 2007 Mail this to a friend!
AF6AY -
Making fat-out statements about "resonance is necessary" needs be
tempered a bit with harsh reality on non-resonant antennas actually
working just fine and very large percentage bandwidths..

........................................................
Why don't we examine this resonant antenna is better than a non-resonant antenna crap a little closer..

From the resonant antenna Steppir Website:

3 el
20 mtr gain ---- 4.9dbd gain


From the Tennadyne Log Periodic website:
T6
20 mtr gain ---5.1dbd gain


Realizing that *sometimes* manufacturer's gain figures are not always believable, I think these are fair figures.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

So here we have a non-resonant antenna beating up on a resonant antenna. Lordy HOW CAN THIS BE?

Is not the Steppir an INCREDIBLE antenna as some has said? Wait there is more. The Tennadyne is only $489 DELIVERED. The Steppir is a $1600 antenna with shipping and cable.

How can a non resonant cheap LP antenna beat a expen$ive *INCREDIBLE* Steppir resonant antenna. HARSH Reality Perhaps???

LMAO
Stan K9IUQ








 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 11, 2007 Mail this to a friend!
"Making fat-out statements about "resonance is necessary" needs be
tempered a bit with harsh reality on non-resonant antennas actually
working just fine and very large percentage bandwidths.."

Yeah, but W4LGH is a 50-ohm-at-resonance antenna element zealot.
 
RE: Antenna Lessons from the Old Timers  
by WA4DOU on June 11, 2007 Mail this to a friend!
"How can a non resonant cheap LP antenna beat a expen$ive *INCREDIBLE* Steppir resonant antenna. HARSH Reality Perhaps???"

Actually Stan, it doesn't. The truth about the gain of the typical LPDA is that for quite a number of years it has been overstated by about 2 db. The T6 offers slightly over 2 dbd gain on 20 meters up to about 3.5 dbd on 10 meters. Go to W4RNL's website and seriously investigate LPDA's and you'll find just how many elements are necessary and the length of the boom required to obtain comparable gain to the 3 element yagi. Frequency agility has its price.


 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 12, 2007 Mail this to a friend!
You guys are incredible! A Discone, Rhombic and a Log-Periodic, all non-resonant antennas? Wrong! A discone antenna was originally designed to be a receive antenna, but it was found that it became "RESONANT" on MANY of it frequencies! The Rhombic anyenna again was designed as a receive antenna, under the premmiss that "bigger was better" an while it will transmit, it is a poor overall radiator, except for point to point communications. Now a Log-Periodic is no more than a fancy fan or parallel dipole, only it has reflectors and directors to make it directional, and it DOES have "RESONANT" elements on the bands that it covers.

In order for an antenna to radiate energy "effeciently",(ie: absolute maximum energy transfer) it must be brought into resonance either electrically, the use of a matching device, as the reactance and resistance must be close to equalling, or the antenna can be mechanically resonant, ie: 1/2 wave dipole. However uding any device to electrically resonant an antenna WILL do so at a LOSS. This LOSS may be MORE than acceptable to you, and never noticed at the far end, but it IS there none the less. And CAN be measured.

Now for those of you who still do not understand where I am coming from, I am talking about ABSOLUTE EXTREMES! These maximums may NEVER effect your life, but they are there none the less.

73 de W4LGH - Alan
http://www.w4lgh.com




 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 12, 2007 Mail this to a friend!
W4LGH >
"You guys are incredible!"
...............................................

Thank you, We Finally agree.

Stan K9IUQ
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 12, 2007 Mail this to a friend!
"A discone antenna was originally designed to be a receive antenna, but it was found that it became "RESONANT" on MANY of it frequencies!"

Do you have a reference that proves the discone was originally designed to be a receive antenna?

And if it is resonant over a broad frequency range, what does "resonant" really mean?

"The Rhombic anyenna again was designed as a receive antenna, under the premmiss that "bigger was better" an while it will transmit, it is a poor overall radiator, except for point to point communications."

Do you have a reference that proves the rhombic was originally designed to be a receive antenna?

As for "poor overall radiator, except for point to point communications", how can an antenna with so much gain be a poor radiator?

The rhombic is one form of traveling wave antenna. Like the V beam and many others. The rhombic is inherently nonresonant, yet it radiates very well.

"Now a Log-Periodic is no more than a fancy fan or parallel dipole, only it has reflectors and directors to make it directional, and it DOES have "RESONANT" elements on the bands that it covers."

In the classic LP, all the elements are connected to the transmission line. So they cannot be reflectors or directors. Of course some of the elements will be close to resonance, but that's true of many antenna designs.

"In order for an antenna to radiate energy "effeciently",(ie: absolute maximum energy transfer) it must be brought into resonance either electrically, the use of a matching device, as the reactance and resistance must be close to equalling,"

That's true.

"or the antenna can be mechanically resonant, ie: 1/2 wave dipole."

That's not what mechanical resonance means. Not at all.
You are misusing the term.

"However uding any device to electrically resonant an antenna WILL do so at a LOSS. This LOSS may be MORE than acceptable to you, and never noticed at the far end, but it IS there none the less. And CAN be measured."

If the loss of matching and tuning devices is never noticed at the receiving end, why should anyone care about it?

"Now for those of you who still do not understand where I am coming from, I am talking about ABSOLUTE EXTREMES! These maximums may NEVER effect your life, but they are there none the less."

If they never affect my life, why should I be concerned about them?

---

Consider two simple wire antennas:

1) A half-wave dipole fed with coax

2) A nonresonant dipole of about a half wave, fed with open wire line and a good balanced tuner at the shack.

If the feedline is long enough, the loss in the coax will be more than the loss in the open wire line/tuner combination, even though the coax SWR is much lower than the open line SWR.

Which is the better antenna?

----

And now a question:

An amateur puts up a terminated rhombic that is 280 feet per side. It is fed with homebrew balanced line,
and the SWR is close to 1:1 from just below 20 meters to above 10 meters. A broadband balun is used at the shack end of the balanced line. It works very well on 20, 17, 15, 12 and 10 meters, as both a transmitting and receiving antenna.

What is the resonant frequency of the rhombic?

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 12, 2007 Mail this to a friend!
W4LGH pounded on the table and shouted:

"You guys are incredible! A Discone, Rhombic and a Log-Periodic, all non-resonant antennas? Wrong! A discone antenna was originally designed to be a receive antenna, but it was found that it became "RESONANT" on MANY of it frequencies! The Rhombic anyenna again was designed as a receive antenna, under the premmiss that "bigger was better" an while it will transmit, it is a poor overall radiator, except for point to point communications. Now a Log-Periodic is no more than a fancy fan or parallel dipole, only it has reflectors and directors to make it directional, and it DOES have "RESONANT" elements on the bands that it covers."
..............................
<insert clip from the road-gang scene in the film "Cool Hand Luke">

Voice-over: "Whut we got heah is a ... a fail-ure ta communicate!"
...............................

You seem to have a concept of "resonance" that differs from the rest of the radio world.

Resonance in a parallel-tuned or series-tuned L-C circuit occurs when there is no reactive component, only resistance. At that frequency the AC-RF voltage and current are in phase for maximum power flow, bothered only by resistive losses of all components. That principle is applied to active circuits to select/pass a certain frequency, rejecting other frequencies, called "tuning" in the most generic and colloquial sense of the word.

The common, simple dipole will behave similarly - but not exactly - as a simple L-C resonant circuit. It is composed solely of a wire or tube conductive material, no specific inductor or capacitor. At a dipole's "resonance" frequency its total impedance at the feed-point is resistive-only, no reactive component. In a most basic and simplistic application for amateur radio - what some consider 'necessary' for beginner hams - it can be fed with balanced line to a minimum-component transmitter/receiver coupling circuit and achieve maximum power transfer. All well and good at ONE frequency.

However, that wire/tube dipole WILL generate/receive electromagnetic fields at frequencies AWAY from the conceptual-simplistic "resonance" frequency. That is still in accord with James Clerk Maxwell's famous equations. All that is required for maximum power transfer into/out-of that "off-frequency" dipole is to modify its feed-point impedance so that voltage and current are in the proper phase for maximum power transfer. That is what the antenna "coupler" does. However, that coupler's impedance transformation occurs best at only ONE impedance at a new frequency. The coupler must be "re-tuned" (L-C values changed) for each new frequency away from the "natural resonance" of the conceptual dipole impedance.

What is generally ignored in the simplistic concept presentation on dipoles is that EM fields and waves are still being radiated and launched at frequencies AWAY from the simplistic conceptual "resonance" frequency. The maximum EM field strengths are no longer broadside to the ideal "resonant dipole" axis but appear at various angles to that axis. The "resonant dipole" cardioid shape gives way to various blobby patterns as the frequency differs from the "resonant dipole" concept frequency. Everything conductive or semi-conductive (soil) within roughly five wavelengths of this simple dipole will affect BOTH its pattern AND impedance to various distances from these near-field conductors AND at frequencies away from the "resonant dipole" frequency. It is NOT an intuitive concept. The various change-making occurances have been isolated and presented in various texts between 70 to 40 years ago under IDEAL conditions...such as the change in impedance (at the "dipole resonant frequency") with various heights above an ideal ground. Radiation pattern changes were less documented until the advent of the PC and the application of the "method of moments" mathematical matrix calculations thus enabled to analyze millions of short-length EM field generating conductors at any given frequency. That was the NEC or Numerical Electromagnetic Code first done at the Naval Postgraduate School in the early 1980s.

EM radiation, fields and waves of EM energy, have their own equivalents to voltage and current, commonly referred to by the most generic term "wavefront." Again, under the first principles of Maxwell's Equations, it makes no difference whether a wavefront impinges on an antenna to generate an RF voltage and current flow in that antenna's conductors (receiving) or whether RF voltage and current flows to generate an EM wavefront (transmitting). ALL antennas send or receive with no difference in either mode.
[there are specific microwave frequency range components which could be added that CAN make unidirectional RF power flow in coaxial and waveguide systems but they aren't practical at HF...would be too big for anyone]

To get efficiency in ANY antenna is a function of its shape, number of conductors, arrangements, and, if a number of conductors fed separately, the RF voltage-current phasing necessary to induce a power flow to generate the proper EM wavefront of transverse electric and magnetic fields. Beyond the simplistic "resonant dipole" example is a conceptual difficulty that is NOT INTUITIVE. I've not read the original 1953 paper that presented the discone, but the arrangement of conductors and shapes is a most innovative and remarkable thing to have originated well before the existance of the NEC and high-speed computers. Whether or not it was (as you say) intended to be "receive only" is irrelevant and immaterial. By tens of thousands of practical examples, a discone works equally well transmitting or receiving...and can be tailored to fit a certain characteristic impedance over a (practical) 2:1 ratio and maintain a low VSWR over a decade of bandwidth. A discone is NOT "resonant" at any particular frequency in the sense of the simplistic "resonant dipole."

Some texts say a rhombic wire antenna is an outgrowth of the Vee of two horizontal wires. Regardless, the rhombic was first innovated prior to WWII and has a remarkable wide bandwidth at HF with some appreciable gain in its foward pattern. While way too large for any amateur radio application (unless the ham is also up in the millionaire income range) it has served well for decades in thousands of point-to-point communications providers. A rhombic is NOT "resonant" at any particular frequency in the sense of the simplistic "resonant dipole." It's shape, elevation over ground, long length of legs, and proper termination of one end (for directionality) defeat the "resonance" concept. [I've QSYed a PW-15 transmitting 15 KW RF on HF to San Francisco from Tokyo in 1953 and it would tune hardly different than a simple dipole...with that power and directional gain, the NCOIC remarked that San Fran could receive us with a crystal set...hi hi]

A log-periodic antenna is NOT a parasitic-array such as a Yagi-Uda. ALL of its elements are fed radiators, interconnected by balanced feedlines. It has NO "directors" or "reflectors" despite a so-so resemblance to a yagi. But, the elements are both spaced and made in length to a numerically-logarithmic rule that was devised by someone rare who had the intuitive mind capabile of seeing the relationships of conductive elements with a certain RF power flow in those conductive elements' feedpoints in order to generate a directional pattern over a decade of bandwidth...and, with enough elements, can have a reasonably-constant characteristic impedance over that entire bandwidth.
Like the discone, it was innovated prior to the NEC. Again, like the discone, it is NOT "resonant" at any one frequency. It works "both ways" (receiving and transmitting) with a reasonably constant directional pattern over that bandwidth. Note that its element interconnecting feedlines reverse RF power flow phase between each element, again something that is not intuitive. While too expensive an investment for anyone but rich ham beginners, it is typical of a class of NON-resonant antennas that have appeared within the last half century. A few extraordinary minds conceived of a very distinct departure from the simplistic "resonant dipole" and made them all work.

Can "simple" antennas become directional, and with efficiency? Yes, and it has been done in AM broadcasting for over a half century using vertical radiators...plus L-C coupling networks to change the RF voltage and phase into the base of each so that the generated wavefront has certain azimuthal characteristics...and some of those vertical radiators are NOT the "ideal resonant dipole" size! "Efficient?" Yes, they are, and calibrated field strength meters can prove it. Where I worked weekends at WRRR in Rockford, IL, in 1956, their 1330 KHz antenna pattern HAD to have two nulls, one being towards KFAC in Los Angeles (which I visited in 1957 after moving out here).

ANY wire can radiate EM energy from an induced RF voltage-current power flow. Happens all the time and why there are rules against RFI from electronics that were never designed as transmitters. But, it isn't intuitive as to the EM wavefront energy in azimuth or elevation or the RF voltage-current impedance between it and an immediate common ground. Physically-short HF whip antennas on vehicles just won't be as efficient at generating an EM wavefront as a longer conductor. They can be optimized, yes, and texts are full of examples of such...but they CAN radiate (and receive as well) even though they are not "resonant" electrically or mechanically.

A physically-long dipole (i.e., longer than a half wavelength) will show periodicity in its feedpoint impedance where the reactive part of impedance goes to zero leaving only a resistive part, ideal for direct feed with maximum power transfer. Is it "resonant?" Only in the sense of having no reactive part to its feedpoint impedance. It wavefront pattern can vary greatly from the ideal cardioid with maxima broadside to the wire axis. You cannot intuitively state anything about "efficiency" then despite all the talk of "resonance." Model a few with a NEC some time. Change the heights above ground and the conductivity of the soil. The results will shoot down preconceived notions faster than the Red Baron got to be an ace.
.........................

W4LGH: "Now for those of you who still do not understand where I am coming from, I am talking about ABSOLUTE EXTREMES! These maximums may NEVER effect your life, but they are there none the less."
.........................
I've never worked for NIST, where the renamed Bureau of Standards go to extremes in standards. But I did work three years in a Standards Laboratory and am familiar with metrology methods. I don't understand where you are coming from. I've never been off-planet.

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by K9IUQ on June 12, 2007 Mail this to a friend!
To N2EY and AF6AY

From W4LGH: "You guys are incredible!"

.......................................................
Truly wrong ideas from people like W4LGH always seem to bring out truly smart people like N2EY, N4KC, AF6AY and others - you know who you are.

I have always figured after seeing W4LGH rant with wrong information on antennas the last few months that he is stupid on purpose, just so others can show us the right path.

Stan K9IUQ
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 12, 2007 Mail this to a friend!
See there you go calling me names again Stan. I have never been off planet either, and as far as I can tell, the laws of physics hasn't changed!

There is definately a failure to communicate, as everyone on here seems to have to be right, and will go to whatever extremes to prove themselves. I have never said that an antenna that wasn't resonant would not transmit, I said one that was resonant was more effecient!

While everyone is going on trying to prove resonance is when the resistance and reactance equal each other, no one has disputed that as being electrical resonance. I have been talking about physicial resonance.. you know why 40 meters is called 40 meters? The wavelenght is 40 meters in length. So a 1/2wave would be 40 meters or 64.16798 feet @ physical resonance! Now while my ATAS screwdriver antenna will electrically resonant a 40" whip @ the same frequency, there is a much greater loss than using a 64' 1/2wave dipole. Major losses in the matching device, not to mention the capture ratio of the antenna. You can match up a tin-can on 80 meters, but I doubt that you will make many contacts.

73 de W4LGH - ALan
http://www.w4lgh.com
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 12, 2007 Mail this to a friend!
"I have never said that an antenna that wasn't resonant would not transmit, I said one that was resonant was more effecient!"

We understood that. The point is, it's simply not true. Being resonant does not automatically make an antenna more efficient.

"While everyone is going on trying to prove resonance is when the resistance and reactance equal each other, no one has disputed that as being electrical resonance."

Resonance is *not* when the resistance and reactance equal each other.

Resonance is when the inductive reactance and capacitive reactance equal each other.

"I have been talking about physicial resonance.."

You've been saying "mechanical resonance" which is something completely different.

"you know why 40 meters is called 40 meters?"

Yes.

"The wavelenght is 40 meters in length. So a 1/2wave would be 40 meters or 64.16798 feet @ physical resonance!"

40 meters does not equal 64.16798 feet.

There are 39.37 inches in a meter, so 40 meters equals
131.233....feet.

"Now while my ATAS screwdriver antenna will electrically resonant a 40" whip @ the same frequency, there is a much greater loss than using a 64' 1/2wave dipole. Major losses in the matching device, not to mention the capture ratio of the antenna."

That's a specific case where an antenna that is very small in terms of wavelength is inductively loaded. It doesn't prove the general case of the resonant antenna vs. the nonresonant antenna.

And what does "capture ratio" have to do with it?

"You can match up a tin-can on 80 meters, but I doubt that you will make many contacts."

Depends on how big the tin can is.

--

Which is a more-efficient antenna in its most favored direction (assuming the same wire, height, insulators, etc.):

1) A half-wave dipole, resonant at the operating frequency, fed directly fed with coax

or

2) A dipole 1.29 wavelengths at the operating frequency, fed through an open-line section designed to cancel out the reactance and transform the impedance to 50 ohms

The first antenna, all by itself, is resonant at the operating frequency and needs no matching device. The second antenna, all by itself, is not resonant at the operating frequency and needs a matching device (transmission line section) to cancel out the reactance and transform the resistive part to 50 ohms.

Which antenna is more effective in its most favored direction, if the height and other variables are the same?

73 de Jim, N2EY
 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 12, 2007 Mail this to a friend!
W4LGH wrote:

"See there you go calling me names again Stan."
..........................
Stan?

"That's another fine mess you've gotten me into, Ollie..."
..........................


W4LGH: "While everyone is going on trying to prove resonance is when the resistance and reactance equal each other, no one has disputed that as being electrical resonance."

I shall dispute what you wrote. The DEFINITION of resonance in an L-C circuit is when the reactances add to ZERO, leaving only the resistance as finite. The resulting impedance at that frequency is usually described as "purely resistive."

It is NOT "when resistance and reactance equal each other." Never.

That's so basic that you cannot be forgiven for a "typo."

..........................
W4LGH: "I have been talking about physicial resonance.."

The ONLY "physical resonance" that I am aware of is mechanical vibration induced by wind or some "organ pipe" effect wherein wind across a largish pipe/tube can induce an acoustic vibration. I have felt the former but only heard about the latter in antenna structures; I have heard acoustic organ pipes in church and understand their similarity to Helmholtz resonators (of the acoustic kind).

ANY conductor of ANY size or shape WILL create EM wavefronts if fed with properly-matched RF voltage and current. The power in that EM wavefront is determined by the shape and size of the conductors.

I have to assume that your definition of "antenna resonance" is when its impedance at a frequency is purely resistive, no reactances. That is the simplistic description of a "resonant" dipole antenna but is NOT necessary for terms of efficiency in generating an EM wavefront power equivalent. It is a standard simplistic description for those without any prior education on antennas. A more complete description would be baffling to beginners since the more complete description takes considerable time to ingest.
............................
W4LGH: "You can match up a tin-can on 80 meters, but I doubt that you will make many contacts."

If the tin can is tall enough one can radiate a substantial EM wavefront power. See the celebrated "beer can vertical" parties of the 1950s when TIN-plated beer cans were emptied and then soldered together (the knowing would add lengthwise reinforcing wire for structural strength). The tin can diameter was larger than the typical thin-wall conduit then used for a vertical antenna conductor...which made the "resonance" frequency impedance wider. The problem of such a vertical construction was NOT electrical, it was in the sobriety of the constructors after ingesting all that beer, and alignment plus soldering quality suffered as a result. With most beer and other drinks bottled in aluminum cans now and in the recent past, the "beer can vertical" disappeared from ham lore decades ago. Properly constructed it would work very well.

In more complete texts on antennas you WILL find relative bandwidths compared for different conductor diameters of simple antenna structures such as verticals. In general, the wider the diameter, the broader the bandwidth, plus a slight increase in efficiency of launching an EM wavefront with a given, constant RF voltage and current. [see "skin effect"...the more "skin" the lower the conductor losses]

You have neglected the trap-less verticals on the market which claim multi-band operation with positive dbi gain figures. Those achieve their broadbandedness (in the sense of covering many bands) solely via the shapes and arrangments and connections of multiple conductors. Those have many frequencies where their impedances are purely resistive or very nearly purely resistive. They have NO counterpart in a simple resonant L-C circuit but, with some difficulty a multiple L and C model could be constructed for analysis of both impedance v. frequency and EM wavefront equivalent field strength.

I would suggest you review complex number quantities and their arithmetic and impedance and/or admittance of both series and parallel L-C circuits before trying to draw some parallel to "resonance" of simple dipole antennas to L-C circuits. And get correct definitions as used by the rest of the radio world.

Leonard H. Anderson, amateur radio licensee AF6AY and Life Member, Institute for Electrical and Electronic Engineers (a professional association worldwide)
 
RE: Antenna Lessons from the Old Timers  
by N2EY on June 13, 2007 Mail this to a friend!
"I have always figured after seeing W4LGH rant with wrong information on antennas the last few months that he is stupid on purpose, just so others can show us the right path."

In other words, we're being trolled. Like what Chip does. That's quite possible.

I think the reason I and others keep responding is that we're concerned some newcomers might actually think W1YW and W4LGH know what they're talking about.

73 de Jim, N2EY
 
Antenna Lessons from the Old Timers  
by W1YW on June 13, 2007 Mail this to a friend!
I think the reason I and others keep responding is that we're concerned some newcomers might actually think W1YW and W4LGH know what they're talking about.

73 de Jim, N2EY

-------------------------------------

Excuse me--

Are you saying that I provide wrong information?Do you understand the significance of this generalization? Perhaps you wish to re-phrase that in a way that indicates an opinion of disagreement over a specific detail or two?

Do you understand that a false assertion that , as an antenna 'person', I don't know what I am talking about --is defamatory?

Is that your intent?

73,
Chip W1YW
 
RE: Antenna Lessons from the Old Timers  
by AK2B on June 13, 2007 Mail this to a friend!
You know Chip; I never really liked fractal art. I always thought it dry and lifeless. But the picture of the antenna in hand at http://www.bu.edu/bridge/archive/1998/12-11/features3.html is really very beautiful. I envision one of these for 7 MHz on top of my apartment building. It would be built of interlocking Lego type blocks stamped from aluminum.
Antennas are definitely the best use I can see for a fractal :-).

Tom, ak2b
 
RE: Antenna Lessons from the Old Timers  
by N3OX on June 13, 2007 Mail this to a friend!
"Do you understand that a false assertion that , as an antenna 'person', I don't know what I am talking about --is defamatory? "

Sigh.


 
RE: Antenna Lessons from the Old Timers  
by K6LHA on June 13, 2007 Mail this to a friend!
.......................
N2EY: "I think the reason I and others keep responding is that we're concerned some newcomers might actually think W1YW and W4LGH know what they're talking about."
.......................
W1YW wrote in reply:

"Are you saying that I provide wrong information?Do you understand the significance of this generalization? Perhaps you wish to re-phrase that in a way that indicates an opinion of disagreement over a specific detail or two?

Do you understand that a false assertion that , as an antenna 'person', I don't know what I am talking about --is defamatory?

Is that your intent?"
........................

As one with a decade of exposure to James' "messaging" over on Usenet newsgroups, I might provide some insight as to his "intent." :-)

N2EY belongs in a sub-species of the hobby where If It's Been Done Before And Duly Published In The Only Official Publications Of And About Radio (ARRL) becomes the *ONLY* way it can be done. :-) Anyone going against such thinking of the sub-species is: (1) Not a real ham; (2) Doesn't know what he is talking about; (3) Has none of the great experience that Real Hams have for umpty-ump years since teen-age licensing testing..

James bristles more than any porcupine to bluntness. He requires much personal respect for his great knowledge of amateur radio; i.e., he must have memorized every official publication the ARRL ever done, including all those before he was born...even those before I was born (I'm older than the FCC). Being blunt to James - in any way - is to incur an everlasting enmity. [trust me on that] He wants and cherishes respect, even demanding it...on any subject, regardless of his experience or non-experience in that field. :-) Wait until he "profiles" you on here. :-)
.......................................................

Now, in the beginning of this article, Don Keith had a good idea, wrote it with the skill of a professional writer (which he is). But, it's been done before. In print. Not as well as Don did it, in my opinion, but it goes back to ham publications that I was first exposed to in beginning Middle School (1946). Way back in that pre-historic time (to many in here) US hams had only HF and the world above 30 MHz was a deep and mysterious place that few ventured into. The radio world didn't even say 'Hertz,' hadn't been accepted by the physics world yet...one said 'megacycles.' [approved form, maybe 'mc' for short]

Sixty-one years ago, OPEN-WIRE Lines were GOOD. Few hams could afford this "coax" thing; that was for the Military, government, business. Indeed, TV used this newfangled lead-in stuff called "300 Ohm Twinlead." The more popular "war surplus" radios didn't even use balanced lines! [ARC-5 Command Sets, BC-348 general coverage receivers used in bombers of WWII]. Few bothered about gadgets like Lighning Arresters for their HF dipoles. In 1946 there were hardly any multiband antennas, everyone was (usually) rockbound in frerquency so they stayed on one ham band as a rule. "Everyone had trees in their backyard" according to articles in print and those were supposed to be the support for the ubiquitous HF dipole. U.S. Hams "worked DX on HF with CW" and that was that...period...full stop.

Since then LITTLE has changed in all the official publications aimed towards beginners in amateur radio. Never mind that there has been multiple quantum jumps in radio communications technology in six decades. Some new things filtered in grudgingly, squeezed in perhaps, mentioning marvelous "new" things like Slopers, the off-center-fed dipole (horizontal or sloping). Always, always was the stated fact that dipoles are balanced antennas and MUST use balanced line feedlines; a concession was the window-punched Twinlead called "450 Ohm Ladder Line" that appeared much later. NOBODY seemed to make note of the fact that dipoles' actual pure resistive impedance varied from 20 to 200 Ohms depending on height about ground! Textbooks on antennas (not published by ARRL) had shown such fact, but they weren't "official ham" things so many amateurs ignored them. Six decades of saying essentially the same thing (no copyright violations if they own those works) for beginners' first antennas and it is bound to imprint a lot of minds. Too many minds hold fast to those beginners' factoids decades later without bothering to learn much; learning takes time and study and that interferes with playing old-time radio op in their very own radio station...they have reached their pinnacle of success and don't need to learn anymore!

I can't remember when Bill Amidon started his part-time buisness selling toroidal cores in small quantities; it was before his retirement from NBC-RCA in Burbank, CA. Almost from the beginning that little collection of plastic bags included a Balun kit, both core and wire for legal limit RF power. For very low cost a ham could make a Balun to transform their dipoles from balanced feed to unbalanced feed for coaxial cable. For at least a couple of decades there have been ready-made dipole center insulators with Baluns built-in! With just a tiny bit of thinking, hams could arrange their Balun connections so that both poles would have a DC path to the coax and thus offer a BETTER path to a ground-mounted lightning arrester (half-inch diameter coax outside conductor braid is equal to heavier wire than in open-wire lines).

Broadband RF impdeance transformation via iron powder or ferrite cores has been used for at least four decades in radio-electronics circuitry. It can apply to antenna structures too, as in the Balun. Why isn't that realized fully by more? [it is not part of the old-time radio mythos, the lore...not accepted]

But, WHY MUST ham radio beginners go for the dipole FIRST? Why not a VERTICAL? One pole or thing sticking up, a lot simpler installation in more urban residences than the (almost mythological) dipole stick between those two trees. The only thing a dipole "teaches" is the mechanics of supporting wires above ground...and that ain't radio, just mechanics. A vertical embraces the SAME technology involved in transducing RF voltage-current into an EM wavefront as does any dipole, sloper, "G5RV" or other horizontal thingy. The mechanics of mounting a vertical thing are a lot simpler, even the trenching for radials as compared to trying to get a horizontal high enough to get away from the ground. Newer urban residences don't always have tall trees and a few have NO trees. Apartment dwellers with trees inside their apartments can only have bonsai.

VERTICAL antennas are de rigeur for mobile operation. Only a semi-trailer owner could use a dipole on HF. :-) Verticals are the only practical antennas for HTs. Verticals, even the multi-branched multi-band types are less obtrusive to neighbors' esthetic objections than a dipole. Why the emphasis on DIPOLES for beginners? It can't be for theoretical reasons, doesn't make sense for practical reasons. Rhetorical...it is part of the mythos, the lore of early radio. "What has been will always be" to some. Indeed, a few, as N2EY seems to say, "what has been MUST always be." [because that is how He does it...:-( ]

Chip, I think the NEW is exciting, something to look forward to, to think about. Fractal antennas are strange new things to so many. Some think strangeness and/or newness is to be avoided, warded off, guarded against. Thus many jeer at the strange, try to humiliate those who work on the new, advancing the state of the EM art. Everyone must use polite civility done the CW way so I say to you "Fine Business Old Man" with true personal sincerity. :-) Keep on doing your thing, even if some self-defined guru-wannabes object to bluntness.

73, Len AF6AY
 
RE: Antenna Lessons from the Old Timers  
by W4LGH on June 14, 2007 Mail this to a friend!
AF6AY, well put! I have always said that if you always do ,what you have always done, you'll always get ,what you always got! Now where would technology be today, if that were the case? Hmmmm..we'd probably still be working on the wheel!

Some want to quote facts and figures that were written 75 yrs ago, and say, thats the way it is. Where would be with the science of medicine if all the researchers went back to quote publications of 75 years ago, and say thats the way it is.

Some people like to throw fancy titles around, as I guess that makes them sound important or official. Some are truely smart people, some have great memories.

There is ALWAYS more than one way to do something, always room for improvements, and some of us are willing and open to trying to improve, some aren't.

Some just like to argue, and some will just agree to go along with the majority, feeling the majority must be right.

Here are some truths... I am NOT a troll, and things don't always work in the real world, as they are said to in the text books! Most of what I have written have come from my own real experiments, tests & opeations. If you don't like it, so be it, as no one said you had to do it that way.

73 de W4LGH - Alan
http://www.w4lgh.com


Now I know why there are some many different churches in the world! People just can't agree on anything!
 
Email Subscription
You are not subscribed to discussions on this article.

Subscribe!
My Subscriptions
Subscriptions Help

Related News & Articles
DXE-ATSA-1 Works on 160 Meters
Safety Schmafety
2-Element Bent Dipole Yagi
It Was Worth A Try


Other Antennas Articles
DXE-ATSA-1 Works on 160 Meters
2-Element Bent Dipole Yagi