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DX PIPETNNA

Marcos Antonio Veloz Burgos (HI8MVW) on October 16, 2008
View comments about this article!

After years of neighbours crying and complaining to me “some cursing too”due to the bad look of my inverted-V atop the four-floor building I live here in Santo Domingo, I had enough of it,

So to let them know am an easygoing ham I decided to give my setup a better look, and came up with an idea, A VERTICAL FOR DXing, how about that? PVC pipes give us the advantage of been available at most places in the world and so is insulated wire, 14 AWG in my case, so the idea of my DX-PIPETENNA was born, see picture and diagram for details, including radials, the radiating element is only six feet long but the radials are 16.5 feet long, the last one-third of it folded backward on itself to make then shorter. The loop at the top? That loop will take care of the corona discharge.

A length of wire close to half wavelength would give me a low angle signal, and the winding turns at about 1 inch apart would keep it from becoming an inductor…you electrical super-brains figure out why the low impedance close to 70 ohms at the feed point jiji, and even better, am using RG-6 75 ohms coaxial, I get it for free around here.

After building this crazy antenna (it took me less than an hour and about TWENTY US DOLLARS, I turned on my Icom 718 and in minutes, there was on June 12 2008 a 59 report from LA4UOA in Argentina, ever since I have enjoyed lots of QSOs with many parts of the world and my neighbours calling me a real ham 73,s Marcos HI8MVW.

0x01 graphic

Member Comments:
This article has expired. No more comments may be added.
 
DX PIPETNNA  
by CT1DDW on October 16, 2008 Mail this to a friend!
Nice aproach Marcos, the visual finishing look its superb, congratulations. You are a living proof that no mater were, the Radioamateurs are always inventing new tings with new spare hardware. I wonder if your formula 124,5 divided by the Frequency to calculate the lenght of the wire, its ok to other bands. And if the top loop can be used with the same mesure to other bands. Regards from Portugal.
CT1DDW - Filipe
 
DX PIPETNNA  
by K1CJS on October 16, 2008 Mail this to a friend!
Seems to be a nice, clean design. Glad its working for you--but beware of the purists out there. You're probably going to get some negative feedback.

In any case, if it works for you--and it fits where you have the limited space--have fun!
 
DX PIPETNNA  
by KB2DHG on October 16, 2008 Mail this to a friend!
WOW! This is fantastic!
OK so basicly we would use the formula for a vertical wire antenna and just wrap it on the PVC pipe? or how would I know what length to make the radiator and the radials for another band?
This looks like a project I would like to try for 160 meters.
 
DX PIPETNNA  
by W3NRL on October 16, 2008 Mail this to a friend!
Very well done, now that's hamming...
73 de
w3nrl Nick
 
RE: DX PIPETNNA  
by WY3X on October 16, 2008 Mail this to a friend!
QUOTE: KB2DHG This looks like a project I would like to try for 160 meters.

Keep in mind that radials for 160M are quite long (120 feet, very roughly). For what this is, it will work OK on 20M, but some antenna designs do not lend themselves well for the top band. Bandwidth constraints come to mind. If you have the space and trees for support, an inverted "L" would work a lot better on 160M.

I had visions of a similar antenna, and used a varnished carpet tube because it's a lot less flexible than PVC pipe. Contact any local carpet store and ask for one of the carpet tubes. They discard them anyhow as far as I know. For technical reasons, you'll need a brass rod above your coil for tuning (3 or 4 feet). After you have it tuned like you want it, you can dope the whole thing in fiberglass resin to make it waterproof and so the wire can't move around on you. If you feel the need for extra strength, you could even wrap fiberglass cloth around it before coating it with the resin. Before you ask, coating it might slightly change the resonant point, but that's why you need some wire stretched straight out from the tip, so you can prune to resonance. Or get fancy and install a retractable whip so you can tune it on the fly!

There are a lot of variations on this theme, and experimenting is fun!

-KR4WM
 
RE: DX PIPETNNA  
by AA4PB on October 16, 2008 Mail this to a friend!
In spite of your wide spaced turns, your coil still works as an inductor. Thats why your 1/2 wavelength of wire didn't have the expected high feed point impedance. You can't simply measure out a half wavelength of wire and wind it on a pipe and end up with a half wave antenna. It appears that you lucked out with your wire length and turns spacing to get something resonant at 1/4 wavelength and presenting a low impedance feed.

A physcially short (less than 1/4 wavelength) vertical will have capacitive reactance which must be cancelled with an equal amount of inductive reactance in order to achieve resonance. One way to do that is with "linear loading" where the coil is distributed over the length of the antenna as you have done. Other ways are to lump the inductance (coil) at the base or in the center of the antenna.

It's great that it works and you obviously did a very nice construction/finish job. It looks great.
 
RE: DX PIPETNNA  
by K0BG on October 16, 2008 Mail this to a friend!
No matter how much wire you wrap around a 6 foot plastic pipe, you still have a 6 foot antenna. The fact the input impedance is close to 50 ohms was more by chance than design. It also proves the antenna isn't very efficient, the fact you worked a DX station notwithstanding.

Alan, KØBG
www.k0bg.com
 
RE: DX PIPETNNA  
by K8QV on October 16, 2008 Mail this to a friend!
Great job on the antenna. Thanks for sharing.

I'm not surprised you're already getting criticized. Pay no attention. There are always "experts" who have a pocket full of theory and are more interested in test measurements than actual contacts.

Sometimes these antenna discussions remind me of when hi-fi stereo caught on back in the 1960s. Some people just enjoyed the great sound it gave to music, but other "enthusiasts" constantly bickered about which speakers provided the absolute highest frequency response (above the range of human hearing!)

Don't let anybody tell you your antenna is terrible and the fun you're having and the DX you're working don't count because your antenna isn't the pinnacle of theoretical efficiency. Have fun with the hobby!
 
RE: DX PIPETNNA  
by AA4PB on October 16, 2008 Mail this to a friend!
Nobody is criticizing him. Just explaining that you can't simply calculate 1/2 wavelength (468/f) of wire and wrap it into a coil - it doesn't work that way. He happened to pick a combination that worked in his particular case but you can't do it for all combinations of length, diameter, and frequency. It also answers the question he asked - why is the impedance so low?

Also, the radiation resistance (related to efficiency) is determined by the physical length, not the amount of wire in the coil.
 
RE: DX PIPETNNA  
by WA7NCL on October 16, 2008 Mail this to a friend!
High impedance at feed point on short antenna = high losses in antenna system.

You can get the same effect by building an efficient antenna and adding a resistor in series.

I don't understand the appeal of short verticals with 6 foot "radiator" and almost 17 foot long radials?

A really interesting experiment would be to disconnect the vertical part and attach two of the radials to the coax and try that as an antenna.

My bet is that it would work better than the "vertical".

I think what is disturbing to the techno brains is that the title of this article is DX PIPETNNA. It should really be "low profile compromise vertical for 20m".
 
DX PIPETNNA  
by W4KPA on October 16, 2008 Mail this to a friend!
Nobody has pointed it out yet, but an antenna design very like this used to be in the ARRL handbook and antenna book> (It may still be.) The writers recommended a much longer pole and feeding the antenna through a tuning capacitor with either a short whip or capacity hat at the top. It is a compromise antenna, of course, but it was offered as a solution where full size antennas weren't possible or where you needed a reduced visual impact.
 
DX PIPETNNA  
by WX4O on October 16, 2008 Mail this to a friend!
I made an antenna somewhat similar to this in the late '70s. I used a medium diameter bamboo 'pole' that I'd originally bought to use as a spreader on a home brew
quagi. Wrapped it with insulated wire, taped every foot or so. Leaned it on my balcony railing and worked U.S. stations from my apartment in Germany. The DX Pipetenna
is quite an improvement.
 
DX PIPETNNA  
by WA3SKN on October 16, 2008 Mail this to a friend!
A helically wound groundplane will work, but does have a fairly narrow bandwidth.
Suggestion... Mounting a weather-proof autotuner at the antenna base will turn this into a multi-band antenna!
73s

-Mike.
 
DX PIPETNNA  
by N6RK on October 16, 2008 Mail this to a friend!
This design makes no sense. An 8.5 ft CB whip with a small loading coil at the base would be much simpler, and would work at least as well. Also, it would be even less visible to neighbors. The cost would be low.

There is nothing magic about helically wound verticals.
 
RE: DX PIPETNNA  
by N1LO on October 16, 2008 Mail this to a friend!
Nice, Marcos.

Essentially, you have created a shortened 1/4 wave ground plane antenna. So maybe you were lucky in guessing the right amount of helical winding. It's very much like taking a mobile Hamstick and adding elevated radials to it.

Drooping the radials down, as you have done, does push the feedpoint impedance of a ground plane antenna closer to 50 ohms. Don't mind the snotty efficiency comments. I'm not surprised at all that it works well.

Best of all, *you* built something that you can be proud of, which makes you a real ham in my book.

--...MARK_N1LO...--

 
RE: DX PIPETNNA  
by AA4PB on October 16, 2008 Mail this to a friend!
Many seem to be missing the major point: Taking 1/2 wavelength of wire and winding it around a form does NOT make a 1/2 wave antenna. Also, spacing the turns 1-inch apart does NOT keep it from becoming an inductor. Using a 1/2 wavelength of wire does NOT ensure a low angle of radiation. Finally, a 6-foot antenna is a 6-foot antenna and it behaves like a 6-foot antenna regardless of how much wire you put into the 6-foot space.
 
DX PIPETNNA  
by GW0DIV on October 16, 2008 Mail this to a friend!
Just remember it may load up ok and you may work stations from all over the world, but does that really mean it works? No antenna has the right to be classed as "working" without permission from EZNEC, and the aproval of the theorists of course! ;0)

Nice article - anything made from cheap/free junk is always worth a million times more than expensive store bought junk!

Rhys
 
RE: DX PIPETNNA  
by AB7E on October 16, 2008 Mail this to a friend!
N1LO: "Don't mind the snotty efficiency comments."

I've seen only one critical comment so far that was less than kind, and that one was in any case accurate. The rest were honest and straightforward clarifications of fact that should benefit anyone else wanting to homebrew a space-efficient (albeit compromise) antenna.

The last I heard ham radio was still a hobby that valued technical accuracy, even if you don't.


 
DX PIPETNNA  
by K6AKR on October 16, 2008 Mail this to a friend!
The art and science of antenna design is to come with an antenna that works well given existing design constraints. In this case Marcos' neighbors objected to his old antenna and he responded in a respectful and intelligent manner.

73, Art K6AKR
 
RE: DX PIPETNNA  
by K1CJS on October 16, 2008 Mail this to a friend!
>>The last I heard ham radio was still a hobby that valued technical accuracy, even if you don't.<<

Funny, it seemed to others (and me) that ham radio was a hobby where experimentation was acceptable--and so was compromise. After all, this is an article that pointed out that an antenna that wasn't so obvious was needed.

Technical accuracy can also be construed as an accurate description of an idea that was found to have worked out somewhat satisfactorily, not just a by the book approach to a problem.

In my earlier post, I as much as said the purists would come and comment, and so far I haven't been called wrong. Lighten up people--experimentation and the getting around of found problems are as much a part of this hobby as being technically---no, I think another term is more descriptive--politically correct.



 
RE: DX PIPETNNA  
by K0BG on October 16, 2008 Mail this to a friend!
MaxxComm, Comet, and Diamond (maybe others) all make an HF vertical antenna which is nothing more than a 50 ohm resistor with a radiating element attached to the center conductor of the coax. If one reads the reviews on these antennas, you'd believe they're fantastic! Gee, 50 ohm match everywhere, no tuner needed, easy to put up, the neighbors don't notice, etc. The fact is, they're about 35 to 50 dB down from a dipole as has been pointed out in several QST reviews. Yet, they sell!

What all this palaver proves, is that today's neophyte amateurs will settle for mediocracy as long as the ratings system is based on the number of DX contacts they can make.

If you're in that group, great. I'm not!

Alan, KØBG
www.k0bg.com
 
RE: DX PIPETNNA  
by WA7NCL on October 16, 2008 Mail this to a friend!
So my challenge still stands, would loading 2 of the radials as a dipole work just as well, or maybe better? In which case the antenna would be even lower profile without the unsightly piece of pipe.

Nobody's knocking experimenting, but if you're gonna write an article, don't make claims you can't substantiate. It's not fair to any newbies that might read the article and take all the claims at face value.
 
RE: DX PIPETNNA  
by K8QV on October 16, 2008 Mail this to a friend!
I noticed the author is also using a 718. There are radios with more selective receivers available so it is also evident he must not be making any contacts at all!

Marcos, you need a better radio. The dipole would work better, too. But don't even try it unless you can get it up at least 100 ft. Actually, that dipole isn't as good as a 4 element beam. Six elements would be better. Also move over saltwater. Run a kilowatt. Make your coax run shorter. In fact, open wire feeder is the only transmission line REAL hams use.

Remember, just because your station is unobtrusive, inexpensive, works DX and you're having fun, that doesn't mean you're really working DX and having fun. You need to spend your time (lots more) and effort (lots more) attaining maximum efficiency so your signal will be S9 rather than an unreadable S8. Efficiency numbers are what the hobby is all about. If you want to ever actually talk to someone on the radio, take a brief break from your ongoing efforts to build the ideal shack and go use the shack of a REAL ham who has already achieved perfection - if you can find one.
 
RE: DX PIPETNNA  
by AB7E on October 16, 2008 Mail this to a friend!
K1CJS,

I never said the article was a poor one or that the effort behind it was misdirected. The author needed a space efficient antenna and took the initiative to build one that, while maybe not optimum, wasn't that far off. I've experimented with literally dozens of wire antennas, many of which didn't pan out, or weren't technically sound, and I learned from all of them. But as others have pointed out before, there is usually more valid knowledge derived from the comments to eHam articles than from the articles themselves, and to label them all "snotty" as N1LO did is pretty lame. After all, even the purpose of experimentation is to learn, not just to do.
 
RE: DX PIPETNNA  
by K1DA on October 16, 2008 Mail this to a friend!
Apparently in the politically correct world
applying antenna theory to an "experiment" to nail down what has been created and what to expect from it is no longer acceptable and electronic theory is decending into the sort of junk science that brought us "global warming" and "herbal cures for cancer".
Since antennas like these have been around for a long time I don't see it as harsh those "here's what you
have made and here's why it works or doesn't work " comments offered by those who can quantify the "design". To draw (correctly I think) from the audio world I would remind folks of two theories of audio quality-- the "a good stereo is one which 'sounds good to me' (I built a speaker once it "sounded good" to me ) vs "the qualities of a good
audio reproduction unit can be quantified and demonstrated on test instruments" ( I built a speaker once and when I figured out what it would and wouldn't do and why, I set about to make it better")
Why whine, complain, + make snide remarks about those who understand the theory-- is admitting that you might learn something that difficult?

 
DX PIPETNNA  
by K2ID on October 16, 2008 Mail this to a friend!
The only antenna I have ever used is a 132 foot length of #14 wire running along three side of my back yard in a "U" shape at about 40 to 30 feet high. It is connected to a DXEngineering 4:1 balun in my attic. On the ground side of the balun I have about 10 radials cut to quarter wave length on various frequencies, with the two longest being about 42" long. These radials are spread all througout my attic. A short run of coax to the room below is the final piece. I can run it on every band from 160 to 6 meters without a tuner although there is a small area in 80 meters where the SWR goes up to about 3:1 probably due to the length of the wire being a half wave there. Reactance is very close to zero on all bands as measured by my antenna analyzer.

It is basically a longwire with radials. I never measured anything other than reactance and SWR but when other local hams are on the air when I am, I make the same contacts as those with store bought or hand made wire antennas do. I understand that contacts are not a measure of how efficient an antenna is but if it provides me with enough contacts to fill my limited weekend time on the air it is a good antenna.

I like to compare this whole antenna argument to the differences between a low and high priced car. I will not argue that a Honda is as good as a Porsche because it goes as fast as I need it to go but the fact that the Honda can go as fast as I need it to go makes it the best car for my needs. The extra power and status of the Porsche would only serve to feed my ego, not my needs.
 
RE: DX PIPETNNA  
by K1CJS on October 16, 2008 Mail this to a friend!
AB7E, Please excuse my reply to your sentence, but it said otherwise--especially the last 4 words. Not too many can put up full size antennas, and even less can get them up there where they're maximally effective.

Even though the test equipment (antenna analyzers, modeling programs) are cheaper and more available now, (at least in the US) hams got by fine with simple equipment for years and still got their signal out with all kinds of either weird or simple homebrewed 'compromise' antennas that some hams thought would never work--or at least work well. But you don't have to have them or even borrow them to build an antenna. Similarly, even though design materials and measurements for certain antenna designs are available doesn't mean you have to follow them to the letter to build a working antenna.

The statements made implies that it is necessary to build antennas to some kind of minimum standards in order to get them to work. Even though you don't think that is how your statements are perceived, it is by some of us--and even more so by others, hence the 'snotty' comment.

Apologies if my post was taken the wrong way.
 
DX PIPETNNA  
by KI4CRA on October 16, 2008 Mail this to a friend!
Give the man a cigar! He needed a space limited antenna, mulled it over, came up with a design that WORKS FOR HIM. Good grief folks, lighten up, maybe its not the most efficient, maybe other types, configurations would and do work better. It works for him let it go at that. Good work Marcos, I'm glad its working out well for you and you are making contacts with it.


73 de Mark
AI4HO
 
DX PIPETNNA  
by GW0DIV on October 16, 2008 Mail this to a friend!
A guy has a specific antenna need, finds a design, builds it - has some fun with it and learns a little along the way. When he's learn't enough and gotten as far as he can with the antenna he can modify it, scrap the parts to build something else or bin it. along the way he'll learn more and get more enjoyment than he'd get lining the pockets of a local emporium and living his on air life by the trinity of EZNEC, antenna analyser & ultimate efficiecy or nothing! Ham radio is an experimental hobby - lets experiment and learn something!
We should encourge people not just shoot them down in flames for daring to try something without years of research. We're having fun not curing cancer!!

Rhys
 
DX PIPETNNA  
by AA5TB on October 16, 2008 Mail this to a friend!
Thanks for the article Marcos! Looks like a cool antenna.

To the others, the ARRL Antenna Book has suggested for decades to use about 1/2 wave length of wire to start off with when fabricating a helical antenna. Not that the finished antenna would be equivalent to a half wavelength tall antenna, but that this was imperically found to be about how much wire was required to make it resonate over a ground plane.

73,
Steve - AA5TB
 
RE: DX PIPETNNA  
by KG6WLS on October 16, 2008 Mail this to a friend!
You know, I once lived in a CC&R community and had to work with a less than desirable antenna system for HF. I applaud Marco’s efforts working around his neighbors’ distaste of antenna farms but, there could have been a more efficient way to do this. But hey, if you’re having fun and making dismal contacts, then that’s all that counts. Not everyone can have a big gun station with Texas property. HI! :-)

73 de KG6WLS
 
RE: DX PIPETNNA  
by N3OX on October 16, 2008 Mail this to a friend!
"Good grief folks, lighten up, maybe its not the most efficient, maybe other types, configurations would and do work better. It works for him let it go at that"

A lot of people take a lot of flack around here for saying "hey, article writer, the antenna could be a lot better if you simply did "X" or changed "Y""

Sometimes they are real nice about it. Sometimes they don't tiptoe around it, but the constant mantra of "Being able to make DX contacts does not make your antenna *GOOD*" is something we should all listen to. See, you could put up a good antenna, run half a watt, and make lots of DX contacts. That doesn't mean anyone should *recommend* -23dBd antennas for the barefoot HF rig crowd!

People aren't necessarily always trying to say that anyone's particular antenna is *actually bad.* We don't really know that, and often the "nay-saying" crowd overstates their case a bit. We see a -4dBi antenna and cringe ;-)

What I can say with 100% certainty, though, is that I can go home tonight, fire up on a very, very bad antenna... something much worse than it needed to be given some constraints, and I could still come back with a list of DX contacts.

For the health of the hobby, this is something that I think we should all keep in mind. Not that there's something wrong with you if you use a bad antenna, but that you shouldn't consider your DXCC count as a primary indicator of how well *your antenna works*, because you don't actually need a good antenna at all to work a pretty good list of DX. QRPers and mobile operators prove that every day, but running a very bad antenna at a home station is, in my opinion, usually a serious *over*compromise.

Anyone who's having fun with their antenna should absolutely just keep on doing what they're doing! But for those who read antenna articles and antenna reviews *looking for ideas* on how to do very well in a constrained situation should be skeptical of antennas where the only recommendation is a list of DX. That's all I'm saying, and I think it's the basic sentiment of many here.


73
Dan
 
RE: DX PIPETNNA  
by N3OX on October 16, 2008 Mail this to a friend!
"the trinity of EZNEC, antenna analyser & ultimate efficiecy or nothing! "

Ultimate efficiency? Not interested in recommending that to everyone. Too hard to squeeze every last dB out, and you'll never be really sure.

But if you measure your oddball antennas simply by "making contacts" and never really make any A/B tests or other measurements, you can easily toss 10dB out the window without noticing compared to what one could do with more care. Does that mean it's a bad antenna for you? No, not really. Fun for you, that's what matters.

Does it mean some antenna that's down a couple fistfuls of dB vs. a dipole is a bad antenna to recommend to others? I think so.


73
Dan
 
RE: DX PIPETNNA  
by K3GM on October 16, 2008 Mail this to a friend!
KB2DHG said: "This looks like a project I would like to try for 160 meters."

....and that would be called a Minooka Special. Google it!
 
RE: DX PIPETNNA  
by PLANKEYE on October 16, 2008 Mail this to a friend!
THIS IS K8QV:

Great job on the antenna. Thanks for sharing.

I'm not surprised you're already getting criticized. Pay no attention. There are always "experts" who have a pocket full of theory and are more interested in test measurements than actual contacts.

Sometimes these antenna discussions remind me of when hi-fi stereo caught on back in the 1960s. Some people just enjoyed the great sound it gave to music, but other "enthusiasts" constantly bickered about which speakers provided the absolute highest frequency response (above the range of human hearing!)

Don't let anybody tell you your antenna is terrible and the fun you're having and the DX you're working don't count because your antenna isn't the pinnacle of theoretical efficiency. Have fun with the hobby!

________________________________________________

THIS IS PLANKEYE:

Thank you K8QV, that was well said!!

MARCOS, your DX PIPETNNA is AWESOME brother!!

Thank you for the info!! Keep it up!!


PLANKEYE

 
RE: DX PIPETNNA  
by W5WSS on October 16, 2008 Mail this to a friend!
But n3ox I always like your posts and your points are well received here no pun intended. The science of antenna theory can evelope far too many hermits and their socio-anti social behavior. Could it be proven that the negative effects of too little sleep due to very late nights listening to upper HF dead air be directly associated with an attenuated positive outlook? To as much as a 50-75% loss in personality efficiency? Maybe we all are biolgical antennas and we are guilty as charged, too much hellish winding lol. The irony here is that why does a hobby such as ham radio attract so many lossy personalities lol. Would you agree that perhaps not us of course...that perhaps we have been able to relate to resonance vicariously? lol. 73 in jest
 
RE: DX PIPETNNA  
by VA3CWT on October 16, 2008 Mail this to a friend!
Marcos thanks for sharing your project with others, congratulations

Amigo MARCOS gracias por compartir tu idea con otros colegas.tu proyecto me parecio muy bueno.saludos.
GABRIEL VA3CWT / CX2AAU.
 
RE: DX PIPETNNA  
by KI4WCA on October 16, 2008 Mail this to a friend!
Great article!Your antenna looks great too!I am putting up a dxpipetenna as well, but it will be ugly!A full quarter wave of 3/4 inch copper pipe on top of the metal roofed chicken coop.The roof is only 11x21 feet, so efficiency will suffer somewhat.I should have it up within a week or so.Hope to work you on 20! 73 de KI4WCA
 
RE: DX PIPETNNA  
by K5END on October 16, 2008 Mail this to a friend!
Marcos, that's a nice, enjoyable article. Best wishes in your antenna experimentation.

Sometimes criticism can be quite beneficial. Listen to the more knowledgeable ones. Read these websites enough and in time you'll see who knows what they are talking about.

Short of an education in radio physics, read the antenna books as a first source of information.

Aside from the other constructive comments, I noticed your drawing indicates the antenna wire is secured to the PVC pipe by using short pieces of wire to bind it in place. I can't know this without closer examination, but beware that you may have created chokes along the vertical. Also, try to keep the radial bending to a minimum, with no sharp bends.

73, best of luck.
K5END
 
RE: DX PIPETNNA  
by WB5NPW on October 16, 2008 Mail this to a friend!
A very nice implementation of an old idea. This used to be covered in the ARRL Antenna Handbooks back when, called a helically wound vertical i believe. I've tinkered with them myself, looks amazing like a ham stick doesn't it. Good job.
 
RE: DX PIPETNNA  
by AB7E on October 16, 2008 Mail this to a friend!
K1CJS: "AB7E, Please excuse my reply to your sentence, but it said otherwise--especially the last 4 words."

Those last four words were (as was my entire posting) directed toward N1LO, not the author of the article.

73,
Dave AB7E

 
RE: DX PIPETNNA  
by N2RRA on October 16, 2008 Mail this to a friend!
Some of us know of the ineffeciency these types of antennas exhibit, but again the key thing is that he experimented and it worked. Having to compromise due to conflict with his neighbors didn't allow him to fold under pressure.

The point is where there's a will there's a way! I may not need the antenna I'm still willing to give it a try for experimentation purposes.

Thanks for the article and good job!

73,
Eric
 
RE: DX PIPETNNA  
by N2RRA on October 16, 2008 Mail this to a friend!
Oh! One more thing. Nice to see some positive comments. Bravo!

73!
 
RE: DX PIPETNNA  
by N0EQ on October 16, 2008 Mail this to a friend!
As expected. I've heard the naysayers say -
"your DX contact doesn't mean anything,
the antenna can't work the way you've built it".

Phooey to those that want to exist in the theoretical
world.

Stick metal in the air, tune it, make contacts.
THAT is what amateur radio is all about.


Craig 'Lumpy' Lemke
5 watts phone, around the world, daily.
On antennas that the naysayers claim
"won't work"
www.n0eq.com
 
DX PIPETNNA  
by XE3LW on October 16, 2008 Mail this to a friend!
Hola Marcos

Nice looking antenna, I made a similar project myself. I took a 21 ft. fiberglass Marine SSB mobile antenna, in a 20ft pole, instead of the remote antenna tuner, I put a 4:1 balun in the feed point, and a 40 mts Tak-tenna which it is a spiral coil dipole as a ground plane for 40 mts. plus, a .2 wavelength radial for 40 too, 1 for 80 and 3 for 20 mts.
The inboard antenna tuner is mandatory for 80, 40 mts, and Marine freq. 30 mts band need no tuner, 20, 17, 15, 12 and 10 ,are below 1:9 vswr so tuner is optional.
Surprisingly I found this vertical performing a little better on 80 mts. than my homebrew Windom multiband antenna.

Saludos cordiales
Oscar-xe3lw




 
RE: DX PIPETNNA  
by N3OX on October 16, 2008 Mail this to a friend!
""your DX contact doesn't mean anything,
the antenna can't work the way you've built it".

Phooey to those that want to exist in the theoretical
world. "

That's not what *I* mean.

What I mean is that you shouldn't *recommend to someone else* that they build some antenna unless you have some idea, any idea, how it stacks up in some real units.

I'm doing a little experiment. I have a quarter wave 80m vertical. That presents something like 1300+j1300 ohms. If I total up all my "theoretical" predicted tuner and feedline losses, I get something like 7dB system loss if I just go ahead and tune the antenna from the shack with my MFJ-941E.

Doing A/B tests on a shortwave station with the AGC off, recording some audio so I can do some averaging, shows the difference between the properly base matched vertical and the tuned-from-the-shack version is even worse that my 7dB prediction. It's something between 10dB and 15dB.

That's not me off in la-la land imagining some loss. That's me switching back and forth between a high Q network right out at the base of the antenna to match it on 40m and just "compromising" and tuning it in the shack. The shack-tuner system seems to show 10dB real world loss, very possibly more.

So, let's make some contacts.

So far I've worked ZC4VJ, I1YRL, and C57R (who had a pileup). I'm waiting for CE0Y/JJ2NYT to come back around to threes, though I might have to go ahead and put my extra 10dB back for that...

To you, Lumpy, this is no surprise. You're working the world with five watts (and be honest, you put up decent antennas). I'm working some DX with 10W effective radiated power.

But, if I went around telling people that a 1/4 wave vertical fed with sixty odd feet of mixed 50 ohm coax, tuned with a cheap tuner in the shack such that I had 10dB overall system loss was a GOOD ANTENNA, well, I'm not doing anybody any favors.

If there's something in it for me, okay, fine, I can run my 10dB-loss abomination and heat up some coax while increasing my 40m DXCC totals. But it's not cool for me to tell people that such a system is a GOOD ANTENNA when a simple dipole at 30 feet or the proper LC circuit at the antenna base would make it 10dB better!

This is a REAL experiment done with a REAL antenna system and REAL DX. This is NOT a good way to feed an antenna, there are several very easy improvements I could make to this system. In my case that's as easy as flipping a switch, but you could also just add a second 33 foot wire stood off from the mast that supports the 80m vertical too. A dollar of wire and you end up with the equivalent of buying an amplifier.

And yet, with my crappy antenna system which I would "nay-say" all day long, I worked some DX. It's just not a good measure of antenna performance. Working DX on bad antennas is just a good measure of how cool ham radio is, that's all.

And I don't want to suggest that the subject of this article is a "bad antenna;" it's probably middle-of-the-road as far as shortened doohickeys go. I just want people who are reading and deciding what antenna they should put up for DXing to realize they need to look at things that actually measure ANTENNA parameters. DX is not one of them. People don't work DX because their bad antenna is good, they work it in spite of their bad antenna. People buy all manner of junk in the pursuit of DX because someone gives something a 5/5 eHam review like "wow, I worked ZC4VJ, I1YRL and C57R on 40m CW the first night I used this antenna!!!!!!!!!"

73,
Dan

 
RE: DX PIPETNNA  
by N3OX on October 16, 2008 Mail this to a friend!
I said:

"I have a quarter wave 80m vertical. That presents something like 1300+j1300 ohms"

I meant it does that on *40m* where I ran my tests. Sri, read this before you read that ;-)
 
RE: DX PIPETNNA  
by KZ1X on October 17, 2008 Mail this to a friend!
Dan, if you want to *really* talk about how cool ham radio is ... you have to consider the antenna-age coefficient ... and that is hard to measure with conventional test gear. Marcos' antenna, for example, will actually IMPROVE in performance over the next 5-6 years, without making any of the suggested modifications! All he has to do is leave it up. Clearly, the antenna has to 'mellow' to get to the maximum performance, not unlike a fine whiskey. Nobody ever talks about this little secret ...

 
RE: DX PIPETNNA  
by K1CJS on October 17, 2008 Mail this to a friend!
>>What I mean is that you shouldn't *recommend to someone else* that they build some antenna unless you have some idea, any idea, how it stacks up in some real units.<<

Pardon me, but I didn't see a recommendation anywhere in the article. What I saw was just a description of how a ham made an antenna, and how he made a contact with the antenna--thats all.

Geez guys, stop being so critical, will you? The guy just put together a little story about something he did. If it benefits another ham-or gives them some ideas about how they can possibly do things, well, that's what this site is here for, isn't it????
 
DX PIPETNNA  
by K0FF on October 17, 2008 Mail this to a friend!
Marcos said"you electrical super-brains figure out why the low impedance close to 70 ohms at the feed point jiji"


I agree 100% Marco, if it's fun and it works for you, why not. I have a Beverage receiving antenna that is nearly vertical. It runs down the face of a bluff from my house and is terminated in a 600 Ohm resistor grounded in a creek at the bottom. Not supposed to work, but heard 3Y0PI just fine on 160M when stations hundreds of miles south of me heard nothing.

Also this same antenna is used on higher bands as a transmit antenna, since the resistor is a very large Wattage one, but have to admit it is very directional!



Geo>K0FF
 
RE: DX PIPETNNA  
by N3OX on October 17, 2008 Mail this to a friend!
"If it benefits another ham-or gives them some ideas about how they can possibly do things, well, that's what this site is here for, isn't it???? "

Yes indeed, but as part of that benefit, I think it's also reasonable to raise questions in the comments on these articles about whether or not a particular approach to an antenna design could be improved, especially to point out various points *to the other readers of the article.*

And as far as people getting ideas from the articles, that's *exactly* what I worry about.

Everyone loves helical distributed loading because by some accident of distributed inductance and capacitance you can often resonate a half wavelength or a quarter wavelength of wire on a much shorter form. But the resulting antenna is MUCH different than an extended half or quarter wavelength of wire, and resonance isn't everything. This antenna's direct match to 75 ohm coax is possibly bad news as far as efficiency goes.

- - - - - - -

But I have kind of a funny perspective on this. I don't really have a problem with a lossy antenna design. I have a problem with antenna designs that are likely confuse people's learning process.

The distributed helical load should probably die. It's one of those things that's very complicated and yet seems simple. There are enough free parameters in it that the home builder can often achieve resonance from a random combination of length, and diameter.

But in the end, it's hard to draw conclusions from that. It's one of those antennas where the resulting resonance gets attributed to the quarter-waveness or half-waveness of the original wire or whatever, when it's actually a complicated function of distributed inductance and capacitance that got juggled by the builder till it was just so.

It should be reproducible, but there's nothing really to recommend doing so other than it looks cool.

Maybe that's enough for you or Marcos, but for the sake of people who want an effective antenna, I want to warn people away from a distributed helical loading design, and more generally, away from antennas that have as the only measured parameters a good match to coax and a handful of DX contacts.

A lot of information about antennas on the internet is directly counterproductive to learning about them.

73
Dan





 
RE: DX PIPETNNA  
by AA4PB on October 17, 2008 Mail this to a friend!
I agree, Dan. The basis for his design (1/2 wavelength of wire) is not scalable to other bands. If you take 67 feet of wire and wrap it on the form it will quite likely not be resonant on 40M and won't present a 70 ohm load.

If the 1/2 wave of wire was really working as a 1/2 wave antenna then the feed impedance would be around 2000 ohms instead of 70 ohms. The antenna is probably functioning more like a 1/4 wave with a feed impedance of around 20 ohms plus 50 ohms of loss resistance. His design criteria is intuitive - but not technically correct. He apparently happened to land on a combination of wire length, spacing, diameter, and antenna length that worked for 20M. It might be a good time for him to play the lottery :-)

Hamstick (and others) have been making 8-foot helically loaded antennas for years so it can certainly be done for any HF band. They didn't do it by simply cutting the wire to 1/2 wavelength however.
 
RE: DX PIPETNNA  
by N3OX on October 17, 2008 Mail this to a friend!
"Hamstick (and others) have been making 8-foot helically loaded antennas for years so it can certainly be done for any HF band. They didn't do it by simply cutting the wire to 1/2 wavelength however.
"

You sure their design process is any better? I'm not.

;-)
 
RE: DX PIPETNNA  
by K1CJS on October 18, 2008 Mail this to a friend!
>>And as far as people getting ideas from the articles, that's *exactly* what I worry about.<<

Dan, why should you worry? There are no guarantees in anything. A person may put together an antenna strictly by the book--an 'approved' design, and may not get any worthwhile use out of it. On the other hand, a person may throw a wire up in a tree and get all kinds of results. In any event, a person takes their chances, and its nobody else's fault if they succeed or fail.

So, Dan, as I asked--Why do you worry? Is it because of the warped way of thinking these days? It is because of that way of thinking that some people feel compelled to stick their noses in places where they don't belong. Such as people being concerned with what is being done on someone else's land--like a tower going up. One inevitably leads to another.
 
RE: DX PIPETNNA  
by K1CJS on October 18, 2008 Mail this to a friend!
No, I'm not accusing you of doing that.
 
RE: DX PIPETNNA  
by KI4UCO on October 18, 2008 Mail this to a friend!
If you want a restricted space antenna for 160m, try this project I found online:

http://www.iw5edi.com/ham-radio/?a-practical-antenna-for-160-metres,32

Good luck, 73
Todd
KI4UCO
 
RE: DX PIPETNNA  
by AA4PB on October 18, 2008 Mail this to a friend!
You sure their design process is any better?
-------------------------------------------------
I'm sure they are not taking 1/2 wavelength of wire and winding on the form for each of the bands. I doubt that you can even get 135-feet of wire wound onto a tiny Hamstick form :-)

 
RE: DX PIPETNNA  
by N3OX on October 18, 2008 Mail this to a friend!
"So, Dan, as I asked--Why do you worry? Is it because of the warped way of thinking these days? It is because of that way of thinking that some people feel compelled to stick their noses in places where they don't belong."

Chris,

Ham radio is a two-way hobby. When people run crappy antennas without being really limited to running crappy antennas, everyone loses. Others lose out because they get more frustrated than they need to. People who are trying to learn how antennas work lose out because the easily, freely available information they find on the internet (and very possibly on the air) is 75% misleading folklore that eventually has to be unlearned. And, if you need to attribute a selfish motive to my words and actions, I lose out when other stations are too weak to work because they over-compromised on their antenna installations even as I attempt to push mine up as far as I can against my constraints.

I'm not right all the time when I give antenna advice, but I will accept technical criticism and corrections readily. If I'm giving incorrect antenna advice, I absolutely want to be set straight.

But I won't really accept the idea that other people's antennas are "off-limits" to the point where I should not comment on them. What they do on their property, sure. What they believe about God or lack thereof. Not my business. What they do in their bedrooms? Also not my business.

Myths, legends, and folklore on the internet that cause other hams I might want to talk to to have weak signals? As I see it, that actually materially interacts with what I want to do with ham radio, and is at least a little "my business."

I try not to be abusive about it; I try to tread at least a little softly around people's feelings, but I do think that criticism of eHam antenna articles is, in fact, an appropriate use of this little textbox here, and I appreciate criticism just the same when I say something wrong.

But I don't think your questions about my motives are good criticism. The sad state of antenna information on the internet is bad for ham radio, and I want to do good for ham radio.

It'll always be possible to spin the motives of the "antenna criticizers" and the "nay-sayers" toward something distasteful, but since that's not my intent, I'm pretty much going to ignore the attempt to label my motives as something distasteful and unpleasant.

My words are just words, and I don't think that anyone who reads them will be mortally wounded to the point where they can't respond to me and speak their peace. If someone is so deeply offended by my criticism of the type of antenna they built as a home project that they perish, well, for that I am truly sorry.

Marcos built a very nice looking antenna that is of an electrical design that probably shouldn't get as much builder attention as it does, and eHam decided to run the article. As a "hey look what I did" article, I have no problem with that. I like the look of the antenna and it could certainly be worse as far as performance. ***BUT*** I think that others in the same situation should probably look toward a different design, even if this one works just fine for Marcos.

73
Dan
 
RE: DX PIPETNNA  
by WA4DOU on October 18, 2008 Mail this to a friend!
Around 1983 or '84, I found myself in an apartment with no antenna and made a 40 meter, 7.5' tall, helically wound vertical on a 2" dia. wooden dowel rod. Tuned with a noise bridge and matched with an L network and operated over a few radials, it wasn't much of an antenna. Just 2 or 3 years before, I had a 43 ft. tall vertical over 100 fifty foot radials so I knew this antenna wouldn't be much, and it wasn't. I quickly discarded it and buried 150-200 ft. of cheap RG-58 coax
out to a tree in an adjacent field and erected an inverted vee. Unless you could make a helical vertical a substantial percentage of a quarterwave high on 160-80 or 40 meters, I'd say "forget it". A desire to experiment with antennas is commendable but why reinvent the wheel? Antenna science is well known and antenna books will allow one to bypass a lot of futile experimentation that has already occurred with others. The author is to be commended for being willing to take the plunge into antenna experimentation. His antenna roughly compares to a mobile antenna and on 20 meters and shorter wavelengths, these can be efficient enough to make plenty of contacts. If he's happy, that's all that's important. It is up to each and every ham to decide what he/she will find acceptable.
 
DX PIPETNNA  
by WA9DLS on October 18, 2008 Mail this to a friend!
After reading this whole thread,my brain has become mush. As a new Ham I didn't learn a darn thing,except experimentation is a big part of ham radio, and should remain so,it's what ham radio is all about. Or at least thats what I was taught. Sure wish I was as smart as all the other long time hams.......Maybe macros and I will be smarter after some more experiments.
 
RE: DX PIPETNNA  
by AE5EH on October 18, 2008 Mail this to a friend!
(1)

"RE: DX PIPETNNA Reply
by K1CJS on October 17, 2008 Mail this to a friend!
>>What I mean is that you shouldn't *recommend to someone else* that they build some antenna unless you have some idea, any idea, how it stacks up in some real units.<<

Pardon me, but I didn't see a recommendation anywhere in the article. What I saw was just a description of how a ham made an antenna, and how he made a contact with the antenna--thats all.

Geez guys, stop being so critical, will you? The guy just put together a little story about something he did. If it benefits another ham-or gives them some ideas about how they can possibly do things, well, that's what this site is here for, isn't it????"

=======================================================
(2)

DX PIPETNNA Reply
by K1CJS on October 16, 2008 Mail this to a friend!
Seems to be a nice, clean design. Glad its working for you--but beware of the purists out there. You're probably going to get some negative feedback.

In any case, if it works for you--and it fits where you have the limited space--have fun!

=======================================================
(3)

RE: DX PIPETNNA Reply
by K1CJS on October 16, 2008 Mail this to a friend!
>>The last I heard ham radio was still a hobby that valued technical accuracy, even if you don't.<<

Funny, it seemed to others (and me) that ham radio was a hobby where experimentation was acceptable--and so was compromise. After all, this is an article that pointed out that an antenna that wasn't so obvious was needed.

Technical accuracy can also be construed as an accurate description of an idea that was found to have worked out somewhat satisfactorily, not just a by the book approach to a problem.

In my earlier post, I as much as said the purists would come and comment, and so far I haven't been called wrong. Lighten up people--experimentation and the getting around of found problems are as much a part of this hobby as being technically---no, I think another term is more descriptive--politically correct.


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

(4)

RE: DX PIPETNNA Reply
by K1CJS on October 16, 2008 Mail this to a friend!
AB7E, Please excuse my reply to your sentence, but it said otherwise--especially the last 4 words. Not too many can put up full size antennas, and even less can get them up there where they're maximally effective.

Even though the test equipment (antenna analyzers, modeling programs) are cheaper and more available now, (at least in the US) hams got by fine with simple equipment for years and still got their signal out with all kinds of either weird or simple homebrewed 'compromise' antennas that some hams thought would never work--or at least work well. But you don't have to have them or even borrow them to build an antenna. Similarly, even though design materials and measurements for certain antenna designs are available doesn't mean you have to follow them to the letter to build a working antenna.

The statements made implies that it is necessary to build antennas to some kind of minimum standards in order to get them to work. Even though you don't think that is how your statements are perceived, it is by some of us--and even more so by others, hence the 'snotty' comment.

Apologies if my post was taken the wrong way.

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

(5)

RE: DX PIPETNNA Reply
by K1CJS on October 17, 2008 Mail this to a friend!
>>What I mean is that you shouldn't *recommend to someone else* that they build some antenna unless you have some idea, any idea, how it stacks up in some real units.<<

Pardon me, but I didn't see a recommendation anywhere in the article. What I saw was just a description of how a ham made an antenna, and how he made a contact with the antenna--thats all.

Geez guys, stop being so critical, will you? The guy just put together a little story about something he did. If it benefits another ham-or gives them some ideas about how they can possibly do things, well, that's what this site is here for, isn't it????

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

(6)

RE: DX PIPETNNA Reply
by K1CJS on October 18, 2008 Mail this to a friend!
>>And as far as people getting ideas from the articles, that's *exactly* what I worry about.<<

Dan, why should you worry? There are no guarantees in anything. A person may put together an antenna strictly by the book--an 'approved' design, and may not get any worthwhile use out of it. On the other hand, a person may throw a wire up in a tree and get all kinds of results. In any event, a person takes their chances, and its nobody else's fault if they succeed or fail.

So, Dan, as I asked--Why do you worry? Is it because of the warped way of thinking these days? It is because of that way of thinking that some people feel compelled to stick their noses in places where they don't belong. Such as people being concerned with what is being done on someone else's land--like a tower going up. One inevitably leads to another.

=======================================================
(7)

RE: DX PIPETNNA Reply
by K1CJS on October 18, 2008 Mail this to a friend!
No, I'm not accusing you of doing that.

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

Did I miss one Princess? Define the technical merit of your posts Princess. Can you do it?

Better yet, Have you formally analyzed this antenna? Have you built it? Have you modeled it?

Can you do it?

Inquiring minds want to know.

Chrissy Princess, Of the many books available, consider getting your hands on the latest edition of the ARRL Antenna Handbook. Put some time into studying it. Take a look at the Enzec software too. Also consider Bill Sabin's "HF Radio Systems & Circuits, Second Edition. We'll give you the benefit of the doubt you already have basic electronics theory down. Since you state you don't come to eham very often (but you forgot to quit posting)you can put that time into studying. Maybe after a couple of years you can come back and at least intelligently ask questions in the antenna, or other articles here at eham. Or, who knows....You might even be able to write an article. And while you're at it, if you get bored or restless, (although that should keep you busy for a while) you can digest Walt Maxwell's Reflections II. Get Walts stuff down cold, and you can come back and stir things up, provided you get some of the other basics down along the way. Really Princess, you complain and complain to any open ear about how bad eham is. So why don't you put up (by at asking questions, or making comments that are in line technically with the article, or have some technical value at all), or shut up?

Inquiring minds want to know


Terry-AE5EH
 
RE: DX PIPETNNA  
by K1CJS on October 18, 2008 Mail this to a friend!
Keep it up with the namecalling, Terry. I don't care one way or another--and you're showing the others here what you're really made of.
 
RE: DX PIPETNNA  
by WA2E on October 18, 2008 Mail this to a friend!
Coax! Blah! Not enough antennas fed with ladder line or window line or twinlead. Eliminate the losses. Be a real ham. :-)

Mike

 
RE: DX PIPETNNA  
by N0EQ on October 18, 2008 Mail this to a friend!
k0bg wrote:
"What all this palaver proves, is that today's neophyte amateurs will settle for mediocracy as long as the ratings system is based on the number of DX contacts they can make. "

Shame on a ham basing his success on the number
of DX contacts he can make.

Ham radio is NOT about making contacts?
But about what someone's guess is about
where the X and Y fall on the graph?

Sheesh!


Craig 'Lumpy' Lemke

www.n0eq.com
 
RE: DX PIPETNNA  
by AE5EH on October 18, 2008 Mail this to a friend!
"RE: DX PIPETNNA Reply
by K1CJS on October 18, 2008 Mail this to a friend!
Keep it up with the namecalling, Terry. I don't care one way or another--and you're showing the others here what you're really made of."

Fine business Princess.

They could probably care less.

A couple of your stupid mindless replies that add almost zip of technical information to the subject article is one thing. But 7....? K0BG's and N3OX's among others like them are usually interesting to read. Their information is good review, and often adds something to think about. They use accepted technical data to back up their critiques. Where's yours Princess? Perhaps if you took the time to learn some you would be less likely to perceive theirs as picking at things just to pick at them. Get a clue Princess. Let the article return back to subject. It wasn't bad reading before you started posting your technically worthless comments and arguing with folks who clearly knew much more about what they were talking about than your do. But that's what you do. Without fail. Almost any thread, anywhere. Go read them. Maybe it will click with you. But I doubt it.

Get you clue Princess. You can do it.
 
RE: DX PIPETNNA  
by N3OX on October 18, 2008 Mail this to a friend!
"
Ham radio is NOT about making contacts?
But about what someone's guess is about
where the X and Y fall on the graph? "

So, Lumpy, should I go ahead and keep using my 80m vertical on 40m without switching in the matching network I built?

It makes contacts.

Look, I'm not really interested in convincing you on this point. My comments are aimed, mostly, at the ham who's interested in making the most of his or her station within their limitations and who's feeling a little frustrated with their installation.

In that case, there are antennas that are worth working with, and others that aren't. Not all antennas are the same, and there *are* real measurable differences between them, that in the long run, in the BIG PICTURE, mean some antennas do better than others.

And I hope you understand by "measurements other than working DX" I mean things like... OK, you've got some fancy wire antenna that someone's recommending. Is it better than the dipole you have up? Well, TRY it ... don't take the dipole down first. Put 'em both up at once. Based on what I see on your website, I doubt you actually disagree with me on that point...

73
Dan
 
RE: DX PIPETNNA  
by K5END on October 18, 2008 Mail this to a friend!
Pardon an analogy. Indulge me.

Whilst in college I drove a mid-1960's Mustang. The value of the 302 in^3 (5 liters for you young pups) 4 barrel carb, automatic, A/C etc. were overshadowed by timing and dwell that never would stay right, power steering hoses with a propensity for failing, at least one burnt valve, and an elusive exhaust leak I never did find...you get the picture.

Did it run? Sure did. Was it fast? Pretty darn fast, measured by radar--with tickets to prove it. Did it allow some serious babe time? <If only you knew...>

Was it a good car? Hell no. I had to work on it all the time, and forget safety features. It was a death trap.

Were there superior cars available. Uh, yeahhh.

Why, then did I drive it? It was what I HAD. And I had some fun in that car.

Just because the car functioned and I had fun didn't make it a good car.

As soon as I COULD, I got something better.

One need not be astute to see the point here. To elucidate on behalf of those who don't would be time better spent doing some ham time--on a radio.





 
RE: DX PIPETNNA  
by K1CJS on October 19, 2008 Mail this to a friend!
>>I try not to be abusive about it; I try to tread at least a little softly around people's feelings, but I do think that criticism of eHam antenna articles is, in fact, an appropriate use of this little textbox here, and I appreciate criticism just the same when I say something wrong.

But I don't think your questions about my motives are good criticism. The sad state of antenna information on the internet is bad for ham radio, and I want to do good for ham radio.<<

OK Dan, maybe I did go a little far with my criticism--but it was not meant to be personal. The point you make about the use of the site as a sounding board is a valid one--and one I didn't consider as much as I should have. 'Feedback' IS always valuable. Your comments here are restrained and polite, unlike some others concerning antennas and hobby related items.

We do have slightly different view of things--and that isn't bad, it causes the other to sit back and think a bit. Anyway, thanks for your replies.

73, Chris K1CJS
 
RE: DX PIPETNNA  
by KI6BVW on October 19, 2008 Mail this to a friend!
I totally agree. If your antenna works for you, and you recieve good signal reports, more power to you! I use a 200' loop on the top of my wooden Manufactured Home, it should be a cloud burner, but it hears and transmits barefoot better that the 80 meter dipole right next to it. I talk to contacts on 40 clear back in New England from CA 6 land and on 20 and 10 I've talked to Argentina and Japan. I built the 200' loop and just laid it on the top of my shingle roof. Could not have been simpler. In other words, you don't need a Corvette to drive on the freeway, just like you don't have to have a Titan Monster 45' x 45' 10 element beam to enjoy yourself in Amatuer Radio.
Great article, and as usual it is fun to watch the perfectionists tear apart everything we say that might indicate that we have the same DX contacts that they spent 10,000 bucks to reach. Sure, they can bust the pileups better, but we still get to talk to the rare dxpedition too.
73's de KI6BVW
Warm regards to everyone.
 
RE: DX PIPETNNA  
by N0EQ on October 19, 2008 Mail this to a friend!
n3ox wrote:

"So, Lumpy, should I go ahead and keep using my 80m vertical on 40m without switching in the matching network I built?"

No. You should tear them both down and erect
separate 15 element monoband beams at 2 wavelengths
elevation for each band. In fact, you should use
a different antenna for each 50kcs of bandwidth.

To do otherwise would be using an antenna that
"will not work".


Craig 'Lumpy' Lemke

www.n0eq.com
 
RE: DX PIPETNNA  
by N3OX on October 19, 2008 Mail this to a friend!
Lumpy, point taken.



73
Dan
 
RE: DX PIPETNNA  
by VE4AKW on October 19, 2008 Mail this to a friend!
Stuck in an apartment with my first ticket and no equipment, I acquired a Yaesu Frog 7, and a homemade 5 watt 6L6 one crystal on 7.050 mhz. I used a CB 9 ft whip antenna across a 14 ft room. At the base I built an L network on a piece of wood, and used a wire counterpoise. It worked great on the little 5 watter and nearly covered the entire US in that apartment and 2 DX stations before I got a "real" tube transceiver. I continued to use that antenna until I acquired some antenna real estate to put up antennas. The only trouble I had was when the antenna was out of the bandwidth, the capacitor started to arc once in a while, but it was just an ordinary table radio capacitor. Still, I managed to run that transceiver at full power into that antenna as long as I went to the antenna base and tuned to the markings I made for the band segments. So I do believe shortened antennas do work , but not for great DX unless the sunspots are in ones favour. And like one fellow said, he could attach coax to the radials making it an inverted vee and we all know it has vertical and horizontal polarization both both kinds of antennas, but after bouncing off the ionosphere a few times it's all scrambled up anyway making it a good antenna opposed to a little stick of vertical coiled wire.
 
RE: DX PIPETNNA  
by K6MM on October 21, 2008 Mail this to a friend!
KB2DHG on October 16, 2008 said: "This looks like a project I would like to try for 160 meters."

You might be interested in my homebrew "No Excuses" 160M helically wound vertical made from PVC pipe. Details on my website here:

http://k6mm.com/pages/ant-v160.html

I've worked all states + about 20 countries with it over the last 2 years.

73, John K6MM
 
DX PIPETNNA  
by W5AK on October 21, 2008 Mail this to a friend!
This antenna design is very close to one made and sold by Vantenna. It also uses a helical wound wire arrangement. I used one in Hong Kong last year with pretty good results. Of course, the antenna was on the 31st floor clamped to a metal window frame with one radial draped on the floor. There was no doubt that the efficiency was not really high, but it worked on 40 through 17 meters
 
DX PIPETNNA  
by KF4LVC on October 24, 2008 Mail this to a friend!
Hello Marcos.

I have been an RF Egineer for the better part of 20 years, specializing in customized RF solutions including antenna designs. Many of my past clients demanded a high level of aesthetics, which posed challenges...especially where in-building antennas were required.

I must respectfully disagree with many of the fellows who posted coments indicating that your antenna is not "good" or is "inefficient". I will be building a similar antenna this week. I have seen A LOT of unusal things with RF radiation that does not necessarily fit the text book version of what should or should not work.

Yes, when you coil your wire around a form this way it essentially becomes an inductor. But does this necessarily make your antenna into a "resistor"? No! What it does do is convert more of your radiated power into the H field (magnetic) as opposed to the E (electric) field. This will give your antenna some properties that can not be calculated correctly by the normal formulea for simple vertical antennas. Also, having more energy in the H field may give you some advantages over simple verticals and even some advantages over dipoles.

I would agree with those who indicated that you got a 50 ohm match by chance on 20 meters. Nice surprise. I would only comment that you may want to try feeding your antenna into a tuner and testing out on other HF bands. Obviously, the tuner will take on the matching, but if you can find out how much capacitance & inductance is needed for the antenna to work on a different band, then you can build an antenna for that particular band.

This is what the hobby is supposed to be about. You have done very well with this antenna and, though it may be a "comprimise" antenna in some ways, you may find that it will advantages in other ways. By the way, hasn't Hamstick, Iron Horse, and a doezen other manufactures used similar designs for their mobile antennas (smaller scale, of course)? I think you will find that there are plenty of good comments on eHam reviews for these antennas. I wonder why, then, there are so many nay-sayers that have responded to your article. I would have to say that your antenna should be magnitudes more efficient than a mobile whip on 20 meters.

I love your simple and effective approach. Next time we all get together for Field Day, I hope some of us would have the same ingenuity to build a simple & effective antenna like this for the event. Having tall towers and multi-element beams are great, but they do not test our skills to operate in the field under less-than-optimal conditions. I think your antenna shows what can be done with readily obtained matirials when put into the hands of a skilled operator.

Vince Mates
KF4LVC
 
RE: DX PIPETNNA  
by KI9A on October 24, 2008 Mail this to a friend!
Geat job..as long as you can get on and make contacts, I'm thrilled! keep up the good work!

73- Chuck KI9A
 
RE: DX PIPETNNA  
by G6NJR on October 27, 2008 Mail this to a friend!
get off your Oh so high horse will ya .

the bloke built something it works maybe not perfectly but it still WORKS my mobile antenna works and works well maybe not to your high standards but who cares it actually works that at the ned of the day is what matters is it not .
 
DX PIPETNNA  
by NK5G on October 28, 2008 Mail this to a friend!
Don't let the know-it-alls get you down. Experimentation is what the hobby is about.
 
RE: DX PIPETNNA  
by KF7CG on October 30, 2008 Mail this to a friend!
By the way fellows, One of the really old (60's vintage introduction to Amateur Radio books) suggested a quick rule of thumb for shortened antennas was to use 1/2 wave length of wire wound on a form that was small in diameter to its height and about 1/8 wave long. Of course this was for bare wire.

The whole philosopy in that book was to find something close and then cut to fit.

KF7CG
 
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