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[Articles Home]  [Add Article]  

6 Band Wire Antenna

bob raynor (N4JTE) on April 14, 2009
View comments about this article!

N4JTE; 6 BAND “ RIBBON” $35 ANTENNA

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

This antenna article is geared towards new Hams and antenna builders looking for a very inexpensive 6 band antenna that can be efficiently fed with 50 ohm coax without a tuner.

The inspiration for this design resulted from a visit to my 82 year old neighbor's home who had asked me for some help in dismantling his amazing and increditably beautiful model train set, and box up for his grandson. During this process I was intrigued by his use of 5 and 10 conductor 18 gauge flat insulated ribbon cable for all of the L.V. switching and action devices.

So Begins the Adventure.

To be honest I am getting more and more frustrated with some of the latest marketing ploys being used by commercial antenna manufacturers and their incredible, misleading and unsubstantiated miracle “all band” antennas that will sucker in some poor unsuspecting new ham who will spend his money on a heavily marketed, overpriced, and in some cases, Amazingly reviewed antenna // Toaster.

My plan was to use this relatively cheap insulated wire and find out if was actually possible to get 6 bands cleanly matched to 50 ohm coax. As this antenna was basically built for testing and performance evaluation the construction details are limited and somewhat primitive by most standards so I will leave it to others to refine and permatize, hi.

When I envisioned this concept my only real concern was how all the close spaced wires would inter react. The shorter dipoles will all present high impedance at the feed point when they are not driven forcing the feed line to pick the path of least resistance and best match for the frequency. The 40 meter wire will serve well on the 15 meter band as a center fed 1.5 wl wire.

I am aware that a fan dipole uses the same single feed concept but I believe the Ribbon antenna eliminates all those extra tie off points while maintaining the resultant extra effective radiated height, especially if used in a flat top configuration. Certainly less obtrusive and much less work.

BUILDING IT:

Well you have to start somewhere, so I chose the OMISS net frequencies available at www.omiss.net, as my starting point for the band frequencies and wire lengths. I have built more than enough monoband Inv. Vees at this location with insulated wire so I use my own formula of 450/ freq. to achieve what I'm after with minimal pruning.

You need to approach this antenna one side at a time. The ribbon wire I purchased was only available in 50 ft. lengths so I knew the 75 meter wire would need about 8 more feet to each end to reach 75 meters. It's best to unroll and stretch the wire out to remove the “wire memory”. That accomplished measure out your 5 chosen wl lengths and mark or tape off. As the 75 wire is pretty much done after adding the required wire, separate the next wire, and carefully peal back to the taped off marker and cut off excess. Continue this process for the remaining wires up to the 10 meter point. Yeah I know it seems like a lot of wasted wire but at 6 cents a foot you'll get over it !

0x01 graphic

Repeat the process with the other half of your antenna. I just laid them along side each other and matched all the lengths. Be careful to use a dull knife or fingernail file to separate the wires so as to not break the insulation.

After cutting all your wires to length you will need to have some kind of center support and feedline connector in mind before stripping and soldering the 5 conductors together. In my case I pushed each one thru a ceramic insulator and then carefully stripped and soldered together in preparation for feedline attachment.

The ends of half wave dipoles are at high rf voltage and if too close to others will add unwanted capacitance and tuning problems. For starters I just separated the adjacent wires by about a foot and let them dangle down.


FIRST ATTEMPT.

My goal with this initial attempt was to see basically where or if ,I would get full power out. This would give me the best indication of what was actually radiating and at what frequency. You cannot expect, nor limit yourself, to a 1 to 1 swr as being your goal. The meter will serve only as a guideline to where your wire length and height works in the real world of your backyard.

A quick look at any antenna book will show the relationship between height above ground and radiation resistance in ohms. This inv. Vee at 43 ft. is even a little more tricky to predict especially when the 75 meter antenna is only at .175 wl high and the 10 meter antenna is at 1.2 wl above real ground.

All 6 antennas should range between 20 and 90 ohms with the ends at 10 ft. above ground. The results of the first attempt were very interesting in that at least I was getting full power out somewhere close to the 6 bands of interest. I had my doubts because of introducing the 17 meter antenna into the mix which is not an even multiple of the lowest band, usually considered a no no on multiband antennas

FIRST TRY RESULTS

75----------4.179m      short
40----------7.290m      short
20----------14.190m     okay
17----------17.800m     long
15----------21.553m     long
10----------27.713m     long

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

SECOND ATTEMPT:

I use an eye hook stuck into the top of the fiberglass pole with a masonry string to allow easy up and down access for the cutting and tuning process. I started by adding about 4 ft to each end of the 75 wire and after some diddling ended up with around 3.95m. the only band affected by this change when scanning thru the bands was the 40 meter wire which changed it's apparent resonant frequency to 6.9M and the 15 meter wire also dropped in frequency. A quick trip to the backyard to shorten each end of 40 wire by one foot made no change on the resonance. I then separated the forty from the 75 by dangling about 3 ft. at each end. Obviously the end effect was kicking in because I ended up at 7.1m, close enough for my needs and the 15 meter wire was happy in the middle of the SSB portion.

SECOND TRY.
75--------------3.95m
40--------------7.1m
20--------------14.190m
17--------------17.800m
15.-------------21.300m
10--------------27.717m

THIRD ATTEMPT:

The only bands left to fine tune were the 17 and 10 meter wires which were still too long, so I cut off 6 ins. From both ends of each antenna. The 17 meter ended up at 18.135 and the 10 meter at 29.5 in the FM portion of the band which I actually prefer these days.

THIRD, FINAL TRY, I’m lazy:
75----------------3.95m
40.---------------7.1m
20----------------14.190m
17----------------18.135m
15----------------21.360m 
10----------------29.500m                 

RECAP:

The whole tune/recut exercise took about 6 hours and resulted in a 6 band antenna that will radiate full power out without a tuner. Due to the fact that there are no traps, no loading coils, no tuners and no ladderline needing a balun to match, the only losses will be in the feedline due to it's length and not the result of any mismatch at the antenna feedpoint. I do not have the necessary brain power to model this design and would appreciate a peer review on the modeled radiation resistance and resultant antenna patterns.

Point of interest; The 60,30 and 12 meter bands had around a 3 to 1 swr and were showing 60 to 70 watts out without a tuner. Probably work well with auto tuner.

IF YOU BUILD IT:

1; A simple Plexiglas T, or equivalent with double slots for the ribbon wire and two small holes to tie wrap the coax should be more than enough after waterproofing to ensure stability and strength for a center supported light weight antenna such as this.

2; The 75 wire ends up holding the whole antenna up, so I would attach some masonry string to the center insulator and tie wrap at the band end dangles and a couple of more at the 40 and 80 wires with the string going to tie off points. By tie wrapping you will also prevent the wires from separating at band junctions.

3; Attach small non conductive weights at the drop wires after final tuning.

4; Use a tuner at higher powers to attenuate harmonics and any possible spurious transmitter outputs.

5; If 10 conductor wire is available you can double up the wires for each band providing an increase in bandwidth and power handling. FYI, I had no problems with the 5 wire at 500 watts ssb.

FINAL COMMENTS:

I am not going to waste everyone's time by recounting all my log entries while testing this antenna. I will tell you it is a joy to run from 75 to 10 meter fm and be able to hear what is going on and respond to a cq without fumbling around with antenna switches and tuners. This antenna is nothing more than 6 inv vees at 43 ft. that perform to the laws of physics and will serve you well if you are committed to a little sweat equity to get it working efficiently.

You will not be disappointed with this $35 antenna.

BUILD ; DON'T BUY !

Tnx for reading,

Bob N4JTE

FIRST TRY RESULTS

75----------4.179m short

40----------7.290m short

20----------14.190m okay

17----------17.800m long

15----------21.553m long

10----------27.713m long

SECOND TRY.

75--------------3.95m

40--------------7.1m

20--------------14.190m

17--------------17.800m

15.--------------21.300m

10--------------27.717m

THIRD, FINAL TRY, I'm lazy:

75----------------3.95m

40.---------------7.1m

20----------------14.190m

17----------------18.135m

15----------------21.360m

10----------------29.500m

Member Comments:
This article has expired. No more comments may be added.
 
6 Band Wire Antenna  
by SM4INV on April 14, 2009 Mail this to a friend!
Nice article, will try it but very frustrating to find that your m's does not mean meter but MHz....
72/73 de p-a, se4a/sm4inv
 
6 Band Wire Antenna  
by WX7K on April 14, 2009 Mail this to a friend!
Good article. What gauge wire did you use? I am thinking that you could probably use cat-5 or telephone wire in much the same manner. Seems like the round profile would have a smaller wind loading effect. I have lots of wind in the canyon where I live.
 
RE: 6 Band Wire Antenna  
by K9MHZ on April 14, 2009 Mail this to a friend!
>>>>by SM4INV on April 14, 2009 Nice article, will try it but very frustrating to find that your m's does not mean meter but MHz....
72/73 de p-a, se4a/sm4inv<<<<


3.95 "meters" for a 75 meter band antenna?? I mean, wasn't it obvious that "M" meant "MHz"? Yikes, whatever.

 
RE: 6 Band Wire Antenna  
by K9ZF on April 14, 2009 Mail this to a friend!
CAT5 and telephone wire is twisted, it would not work for this antenna.

Good article! I'll keep my eye out for some good ribbon cable:-)


73
Dan
--
Amateur Radio Emergency Service, Clark County Indiana. EM78el
K9ZF /R no budget Rover ***QRP-l #1269 Check out the Rover Resource Page at:
<http://www.qsl.net/n9rla> List Administrator for: InHam+grid-loc+ham-books
Ask me how to join the Indiana Ham Mailing list!

 
6 Band Wire Antenna  
by NC4TB on April 14, 2009 Mail this to a friend!
Are the lengths listed in the article the final result or the initial effort [I'm lazy too!] 73
 
6 Band Wire Antenna  
by KB2DHG on April 14, 2009 Mail this to a friend!
Fantastic article and idea!
So simple it is too obivous to figure out...

I will definately try this out.

I am using a home brew G5RV. 102 feet across, thats 51 FEET EACH SIDE, (I am using #14 bear copper clad wire) 31 FEET OF 450OHM LADDER LINE.
I connect the coax directly to the ladder line "NO BALUN"
I have it only 23 feet up in an inverted V configuation and it works GREAT! Yes I do have to use a tuner on most bands but even with the poor band conditions, I am working All states and DX too!

When it comes to wire antennas, SAVE your money and build it yourself...
Wire antennas are so cheap to build that it is fun and easy to try experamenting.

I think the author has a great solution to a common problem to multi band wire antennas...
GOOD ARTICLE AND I WILL BE TRYING THIS ONE just for the fun of it.
Remember BUILD IT YOURSELF... It will be much better than any commercial built wire antenna!
 
RE: 6 Band Wire Antenna  
by WA4SCA on April 14, 2009 Mail this to a friend!
Something like 35 years ago, I came across an article on making a counterpoise ground to keep the rf out of the shack. This was before WARC bands, and so could be done with some flat 6 wire rotator control cable available. It worked, and works, well. Same principle.

 
6 Band Wire Antenna  
by KJ4IDH on April 14, 2009 Mail this to a friend!
Thanks for a great post! I must try this...

I believe 4 or 6 strand flat standard trailer lighting wire would also work
 
6 Band Wire Antenna  
by W3NRL on April 14, 2009 Mail this to a friend!
Good article
your idea will snowball and many of us will try it and expand it.
very nice
thanks
 
6 Band Wire Antenna  
by K8YZK on April 14, 2009 Mail this to a friend!
Nice article. What did you use to check the freq before/after making the changes, at the rig or with analyzer?

Kurt
 
RE: 6 Band Wire Antenna  
by W4HLN on April 14, 2009 Mail this to a friend!
Was wondering if this ribbon antenna worked....Saw it in an old 73 mag from the 70's or 80's....The Author swore by it.


Ernie / W4HLN
 
RE: 6 Band Wire Antenna  
by K0BG on April 14, 2009 Mail this to a friend!
Here's a suggestion for next time.

Cut the wires to the bottom of the band, and leave dongles (dangles, what ever you wish to call them) hanging from the ends. When tuning, all you have to do, is fold back the ends, and twist them together. This makes tuning easier, and actually adds a little end effect (a good thing).

Nice project nonetheless, and goes to show you it doesn't take a lot of money to fashion your own wire antennas.

Alan, KØBG
www.k0bg.com
 
6 Band Wire Antenna  
by W4HLN on April 14, 2009 Mail this to a friend!
Here's the another version...It may give you or some of the other guys some idea's on the antenna??

73 Magazine April 1981 Page 46-47

Pocket Portable Seven band antenna
"It's CHEAP easy-to-Build and Effective"
by J. Frank Brumbaugh KB4ZGC


Frank uses a 7 strand ribbon cable for his antenna.
 
6 Band Wire Antenna  
by N3QE on April 14, 2009 Mail this to a friend!
Speaking as a guy who tried both fan dipoles fed by coax and an all-band doublet fed by ladder line: Skip the fan dipole. Go straight to the all-band doublet.

The all-band doublet is easier to construct, easier to feed, doesn't require trimming and pruning on multiple attempts to go up and down.

If you really insist on believing that all antenna feedlines must be coax, you may very well be trapped into the fan dipole. Too bad for you. To me the concept that all feedlines must be coax is reminiscent of "CB thought" where low SWR is the only measure of an antenna. Believe me, it's an irrelevant measure if you use ladder line.
 
6 Band Wire Antenna  
by W4OP on April 14, 2009 Mail this to a friend!
Nicely published. The concept using rotor wire has been around for perhaps 30 years.
I would be interested to see bandwidth VSWR plots as the BW of this form of a fan dipole becomes narrow. In fact even the classic fan dipole has narrower BW than a monoband dipole unless the wires are at 90 degrees to one another ( 2 band).

Dale W4OP
 
RE: 6 Band Wire Antenna  
by N0YXB on April 14, 2009 Mail this to a friend!
Great article and no, fan dipoles have nothing to do with a "CB mentality". Coax was being used by hams long before the CB craze started in the 70's. Doublets are nice, but a lot of us have coax lying around. Now I need to search my junk box for ribbon cable and give this a try.

Vince
N0YXB
 
RE: 6 Band Wire Antenna  
by WA2JJH on April 14, 2009 Mail this to a friend!
4 wire rotor able cable will do very well!!!

10,15,20,40,AND 80M, The 4 wire will alllow cover ALL the bands in between OK too. Try to use 2 or 3 multi-band for even better performance.
 
RE: 6 Band Wire Antenna  
by N3OX on April 14, 2009 Mail this to a friend!
"To me the concept that all feedlines must be coax is reminiscent of "CB thought" where low SWR is the only measure of an antenna"

All my antennas are coax fed.

Oops.

You know a fan dipole doesn't require that you own a good tuner, right?

And it provides INSTANT band switching ability.

I personally hate trying to tune 'em.

And I'm not so sure that you can guarantee best efficiency with close spaced ones like this. That could bear some analysis or testing.

But they have their place, as does coax feed.

There are many advantages of multiple-resonant antennas like these aside from multi-band low SWR.

73
Dan
 
6 Band Wire Antenna  
by KD5RGJ on April 14, 2009 Mail this to a friend!
Am I missing something? 27.713 and 27.717 are not 10 meters.
 
RE: 6 Band Wire Antenna  
by N3OX on April 14, 2009 Mail this to a friend!
"Am I missing something? 27.713 and 27.717 are not 10 meters. "

Yes, you're missing the third try where he actually gets the antenna resonant inside the 10m band.

This is what SWR analyzers are good for... you can check the antenna out of band legally...

Unless you ask a few pedantic nitpickers who aren't quite sure if that level of out-of-band emissions are legal.

It's very useful to know where the antenna is resonant, not just if it's resonant off the bottom or the top of the band. It often allows you to get very close by calculating a percentage correction to a length. The wavelength at 28.500 MHz is 97% the wavelength at 27.717 MHz.

Probably doesn't work so well with a close spaced ribbon, but works pretty well with antennas with little interaction.

73
Dan

 
RE: 6 Band Wire Antenna  
by N3LKA on April 14, 2009 Mail this to a friend!
Nice article. I use this method using 5 conductor flat rotor cable for ground planes on my btv4. Not my idea, I read about it in QST years ago, but it works quite well.

Your article should get someone on the air rather quickly and cheaply.

I don't know if Radio Shack still sells the flat rotor cable or not but that's where I got mine 12 years or more years ago.

73,

Brian N3LKA
 
RE: 6 Band Wire Antenna  
by AB7E on April 14, 2009 Mail this to a friend!
K9ZF: "CAT5 and telephone wire is twisted, it would not work for this antenna. "

Why not? The lengths would be different due to the twist, but they would be anyway if different gauge wire were used. Please explain.
73,
Dave AB7E

 
RE: 6 Band Wire Antenna  
by WB2WIK on April 14, 2009 Mail this to a friend!
Problem I've found with CAT-5 is once you remove the jacket and untwist the wires, what you have is #24AWG wire with very thin insulation.

It hasn't the strength to support anything, if used outdoors.

To make this parallel dipole work without failing, you *must* untwist the conductors and separate the ends of each "band pair" from the rest of the wiring, otherwise the tips of the wires arc through to the other conductors, right through the insulation. Even running low power, the voltage at the tips of wire antennas is very high -- so separation, like the author's "dangles" -- is required.

With CAT-5, these "dangles" are only #24AWG wire.

Doing the same thing with flat cable provides the opportunity to use more appropriate conductor and insulation, like #20 or #18 with an insulation that will hold up to the weather. CAT-5 is not "outdoor" cable to begin with, and is worse when you remove the jacket.

WB2WIK/6
 
RE: 6 Band Wire Antenna  
by K5END on April 14, 2009 Mail this to a friend!


"K9ZF: "CAT5 and telephone wire is twisted, it would not work for this antenna. "
Why not?"

Would have problems depending on which wires you use for each of the "band tails."

The twisted wires will couple to their conjugate partner and detune each other.

There is a balanced line impedance associated with the twisted pair, however since they are bonded at the feedpoint the result is less predictable.

I'd predict such an antenna with 4-pair twisted balanced line would be a nightmare to tune on all bands. Each time you tune one band, it affects the others. I doubt that is a closed form solution, but even if it is you get a fragile matrix to solve.

 
RE: 6 Band Wire Antenna  
by W7ETA on April 14, 2009 Mail this to a friend!
Nice article.
Great prose.
Best from Tucson.
Bob, just a CBer running coax to my tribander.
 
RE: 6 Band Wire Antenna  
by W0FM on April 14, 2009 Mail this to a friend!
I had decent luck with ribbon cable dipoles I built back in the early '80's. Used both computer ribbon cable and rotor cable. I didn't consider dangling the tips of each element like you have, nor did I have the patience to pick at the tuning like you did. Nonetheless, they worked.

I also used 5 conductor rotor cable for a vertical ground plane with similar cable as elevated radials. It was simply hoisted up a tree and down again until I got it cut pretty close. I think that design was in the ARRL Antenna book or Handbook for many years. Might still be.

Nice job of explaining your procedures and construction techniques.

73,

Terry, WØFM
 
6 Band Wire Antenna  
by N6RK on April 14, 2009 Mail this to a friend!
While this antenna will get you on 6 bands with minimal stuff in the air, the bandwidth will be considerably narrower than conventional dipoles. Also, the pattern on the high frequency bands will be full of lobes and nulls due to radiation from the long lower frequency wires. It is definitely a compromise.
 
RE: 6 Band Wire Antenna  
by WA8MEA on April 14, 2009 Mail this to a friend!
We make something similar for SWL's using FLAT rotor cable.

Is there anyone that still makes five wire flat rotor cable? That would be stronger than ribbon wire....

73, Bill - WA8MEA
http://HamRadioFun.com
 
6 Band Wire Antenna  
by N9GXA on April 14, 2009 Mail this to a friend!
Tnx Bob. Again. I just came across a 100' roll of 14 conductor cable. I can strip it in half for 2-100' runs of 7 cond. for about $26 plus shipping.
 
RE: 6 Band Wire Antenna  
by WMCO on April 14, 2009 Mail this to a friend!
It is only a compromise for people who expect differently ..what you would call a compromise will be perfectly acceptable for others. A regular dipole will be a compromise antenna for anyone used to a full size beam, a 2 element beam can be a compromise to someone used to a 6 element beam. As long as it function to the satisfaction of the user it is never a compromise.


J.C.
 
RE: 6 Band Wire Antenna  
by N3OX on April 14, 2009 Mail this to a friend!
"
I'd predict such an antenna with 4-pair twisted balanced line would be a nightmare to tune on all bands. Each time you tune one band, it affects the others. I doubt that is a closed form solution, but even if it is you get a fragile matrix to solve.
"

5 or 6 parallel wires in a ribbon have essentially the same problem. It's a little more nearest-neighbor but I'm sure careful analysis would show that transmission line effects are just as relevant in this antenna as with twisted pairs. Like you said, the fact that they're all driven in parallel from one end will tend to excite common mode more than differential mode, but what couples in the other end is something I have some question about.

You can just ignore that in favor of good practical results with all manner of parallel antennas, but we're probably missing some subtle loss mechanisms... there, I share N3QE's worry about SWR-centrism.



73
Dan







 
RE: 6 Band Wire Antenna  
by W7COM on April 14, 2009 Mail this to a friend!
Wonderful article! This is just the spring project I needed to kick my arse off the computer and get outside.

Thanks aga#9t./ [Lost Carrier..]
 
RE: 6 Band Wire Antenna  
by N6AJR on April 14, 2009 Mail this to a friend!
Great article. this is the essence of the fan dipole, yet he never mentioned the word once, bravo.

I have also used the 5 wire rotor cable from radio shack for this a nd a nother trick is with a 50 foot long piece od rotor cable you measure out the 75/80 wire 50 on wire 1, short the end to wire #2 and come back 16 feet and cut a break in wire #2. this gives you 66 feet on a folded dipole for 80 m. and the rest of wire #2 is long enough for 40 meters with thye remaining # 2 wire, just cut out 1 foot of the #2 wire between the end of the 80 wire and the end of the 40 wire.


this is a useable antenna, and if you are making 1, then make 2, set one up North South on 1 feed line and a second up as East West on a second coax
 
RE: 6 Band Wire Antenna  
by N4JTE on April 14, 2009 Mail this to a friend!
Tnx for all the input, just to reiterate a few points.
A; I aimed for as close to full power out as possible by pruning lengths,as stated in the article swr is nothing more than a guidline, but because a dipole is about the only antenna we can build that will offer a relatively decent match in our backyards without matching systems, I selected this for a new ham to try, and get a relatively efficent 6 bander in the air.
B; If someone out there thinks a $300+, 43 ft. vertical is not a "compromise" antenna than the advertisers have won that one !
C; The Ribbon concept was chosen because it is well constructed and the mechanical bonding of the wires is very strong and very light as opposed to 5 conductor rotor wire of which I have about 200 ft laying around.
D; I have a 60ft. high 165ft. "doublet" center fed with ladderline to the shack. Great antenna on 80 and 40 but would not load up below a 3 to one on 15,17 or 10 meters using a ATR-30. Talk about lobes and nulls !
E; Taking my own advice I jury rigged an old AT-150 auto tuner and had no problem getting out on the WARC bands.
Sure would appreciate a model of this.
Tnx guys.
 
6 Band Wire Antenna  
by WB2GBF on April 14, 2009 Mail this to a friend!
Doh! I'm a model railroader as well as a ham and never put 2 + 2 together. Great idea. In fact, I was thinking about raising my 6BTV to 40 feet and thinking of different techniques to make my radials easy to cut and simple to deploy. This will definitely do it.

Also, I like the antenna because it doesn't require a high power tuner. I'm tempted to build one as well.


 
RE: 6 Band Wire Antenna  
by N3OX on April 14, 2009 Mail this to a friend!
"Sure would appreciate a model of this. "

I'm pretty sure no one with EZNEC or many other NEC-2 programs can do that.

I'm not sure yet if it can be done at all with NEC-2. I'm looking into it.

But I think the continuous dielectric and close spacing will result in a lot of difficulties if not a literally impossible modeling job for most ham software (I don't know if NEC-2 dielectrics can touch, for example)

Where's HFRF to say "I told you so" :-)



73
Dan


 
RE: 6 Band Wire Antenna  
by K5END on April 14, 2009 Mail this to a friend!
"the fact that they're all driven in parallel from one end will tend to excite common mode more than differential mode, but what couples in the other end is something I have some question about. "

Yeah, that is what concerns me.

In my opinion it is a great thing for people to experiment with this sort of antenna. Having QSOs with a compromise antenna is better than none at all.

If nothing else, it is a convenient, low-cost antenna that might work well for stealth applications. Some camo paint, some trees, and bingo.


HOA: We're here about your antenna.

OM: "What" antenna? Do you see an antenna? I don't see an antenna. Do you have the right house? Have a nice day.

OM: Slam door.

OM: Try not to laugh too loudly as they walk back down the driveway, turning, looking, scanning, squinting, scratching scalps, shrugging shoulders. Going away.



 
RE: 6 Band Wire Antenna  
by WI7B on April 14, 2009 Mail this to a friend!

Great article Bob!

Besides showing an innovative way to DIY a simple 6-bnad antenna for cheap, it also demonstrates you will go to any length (no pun intented) to encourage new hams onto the OMISS net!

73,

---* Ken #5193
 
RE: 6 Band Wire Antenna  
by N3OX on April 14, 2009 Mail this to a friend!
"
If nothing else, it is a convenient, low-cost antenna that might work well for stealth applications. Some camo paint, some trees, and bingo."

Absolutely. And for a first antenna for the crowd who feels like they need to get on all bands at once, it's perfect.

But what the current distribution and losses are after you've empirically trimmed a given cluster to resonance on 6 bands? Not so obvious.

 
RE: 6 Band Wire Antenna  
by N4JTE on April 14, 2009 Mail this to a friend!
EXACTLY Dan, Was hoping for some way to back up demonstrated real live performance with some scientific data for the "pedantic" nitpickers, hi.
Regards,
Bob
 
6 Band Wire Antenna  
by G0GQK on April 14, 2009 Mail this to a friend!
Sometimes I wonder about people. This is an excellent article which tells you exactly how to make a simple six band antenna, which doesn't require an ATU, the user can switch quickly and easily from one band to another, its lightweight,has a low VSWR so could be used as a portable antenna. Yet, there are people, who, despite the clarity, manage to misunderstand what is written, respond in a complaining manner, and do a comparison with an antenna which requires an ATU. In the UK we call them planks.

G0GQK
 
RE: 6 Band Wire Antenna  
by N2EY on April 14, 2009 Mail this to a friend!
Thanks for a good, practical article. While the multiwire ribbon dipole goes back at least 50 years, and is not "perfect", it can be an inexpensive real-world solution.

A few small points:

N4JTE: "I have a 60ft. high 165ft. "doublet" center fed with ladderline to the shack. Great antenna on 80 and 40 but would not load up below a 3 to one on 15,17 or 10 meters using a ATR-30."

Two solutions to try:

1) Change the ladder line length and/or the dipole length by a few feet. (Remember that a free-space quarter-wave is only about 8 feet on 10 meters). Your difficulty in getting a match may be because you've hit a combination of ladderline + dipole length that puts a voltage loop and very high impedance at the shack end of the line. A few feet won't make much difference on 80 or 40 but it's a big deal on the higher bands.

2) The ATR-30 is an unbalanced tuner, so you are probably using a balun between its output and the ladder line. Try a different balun, with a different ratio if possible.

The classic dipole-fed-in-the-center-with-ladder-line is an excellent multiband antenna, but it has one serious weakness: it usually needs a good BALANCED tuner at the end of the ladder line. The common unbalanced-tuner-with-a-balun-on-the-output may or may not do a good job, depending on shack-end impedances and reactances.

73 es TNX de Jim, N2EY
 
RE: 6 Band Wire Antenna  
by AB7E on April 14, 2009 Mail this to a friend!

K5END: "The twisted wires will couple to their conjugate partner and detune each other. "


Parallel wires will do exactly the same thing, which is why multiband fan dipoles like this are generally a hassle to tune (and model). CAT5e has pretty tight twists in it for use at essentially UHF data speeds, telephone wire has fewer twists, and parallel wires have no twists at all (at least not intentionally), but they all have wires that couple to each other. As WB2WIK/6 says, CAT5e is pretty fragile stuff and I wouldn't use it for that reason, but unshielded commercial telephone wire is damn tough and should work fine ... or at least as "fine" as any other multiband antenna with weird lobes all over the place.

My point is that twisted wire doesn't make the performance materially any different than for flat ribbon cable.

Dave AB7E
 
RE: 6 Band Wire Antenna  
by N4JTE on April 14, 2009 Mail this to a friend!
N2EY actually the ATR is well suited for balanced 450 ohm feed lines with a substantial internal balun designed for that application, just to be sure my mfj 986 also well designed for ladderline struggles with the high freqs. as mentioned.
The ladderline length was determined by my using the flat top as a 40 EDZ and is 1 to 1 on the designed 40 freq. Omiss at 7.185.
Perhaps the feedline length exibits some problem on the high bands, one never knows, hi.
Tnx for your comments.
Regards,
Bob
 
RE: 6 Band Wire Antenna  
by W6WBJ on April 14, 2009 Mail this to a friend!
The best way to construct such a multi-band dipole is to make the entire antenna from RG-142/U coax. The length/diameter ratio of RG-142/U is particularly appropriate because it results in a very low Q, which means a broad response for QSYing.

In order to guarantee an optimum match, the horizontal portion of the antenna should be built from stripped RG-142/U. Use the inner conductor for the elements on one side of the antenna and the braid for the elements on the other half. You'll need to purchase a 500-foot roll of RG-142/U and use approximately 341 feet of it for the horizontal portion of the antenna and the remaining 159 feet for the feedline. Run exactly 9 feet of the coax from your rig to the nearest window and then run the remaining 150 feet straight up to the antenna feed point.

Remember, a gain of 6 db. is equivalent to increasing your power by a factor of 4!
 
RE: 6 Band Wire Antenna  
by N2EY on April 14, 2009 Mail this to a friend!
N4JTE writes: "actually the ATR is well suited for balanced 450 ohm feed lines with a substantial internal balun designed for that application, just to be sure my mfj 986 also well designed for ladderline struggles with the high freqs. as mentioned."

I don't think the problem is the frequency as much as it is the shack-end impedance of the line at those frequencies.

The tuner can only match a certain range of impedances, and if the combination of feedline+dipole is right, the resulting impedance can be outside that range.

On top of that, most baluns aren't really meant to handle loads that are far removed from their design impedance, (usually 50-75 ohms) nor loads that are highly reactive.

N4JTE: "The ladderline length was determined by my using the flat top as a 40 EDZ and is 1 to 1 on the designed 40 freq. Omiss at 7.185."

So you don't need the tuner at all on or near that frequency, just the balun.

I suggest the following article for a better explanation of the tuner issues.

http://www.somis.org/bbat.html

Personally, I'drefer a simple 1:1 ferrite-bead balun, but otherwise I agree with AG6K.

73 de Jim, N2EY
 
RE: 6 Band Wire Antenna  
by W7NUW on April 14, 2009 Mail this to a friend!
The all-band doublet will give a complex pattern of lobes and nulls depending on what band you're working.

The fan dipole will give the typical double-broadside radiation pattern.

Two very different things.
 
RE: 6 Band Wire Antenna  
by N4JTE on April 14, 2009 Mail this to a friend!
The article was not about my EDZ, only about a well fed 6 band inv vee.
Bob
 
RE: 6 Band Wire Antenna  
by N4JTE on April 14, 2009 Mail this to a friend!
Appreciate all the comments, etc, but looking at the responders to the article, I have never heard any of you guys on 40 ,20,or 80, besides Ken and N9GXA, do any of you guys ever get on the air and actually talk with someone or do you spend your time playing expert on the internet ? If you want to see how this experiment works try OMISS net some time.
Bob.
 
RE: 6 Band Wire Antenna  
by K7LRB on April 14, 2009 Mail this to a friend!
From WMCO: "It is only a compromise for people who expect differently ..what you would call a compromise will be perfectly acceptable for others. A regular dipole will be a compromise antenna for anyone used to a full size beam, a 2 element beam can be a compromise to someone used to a 6 element beam. As long as it function to the satisfaction of the user it is never a compromise.


J.C. "

BINGO!!

73,
de Larry
 
RE: 6 Band Wire Antenna  
by W5WSS on April 14, 2009 Mail this to a friend!
N4jte Nice writ. I am working towards the completion of a fan doublet that is interesting. Mine is incomplete but when I get the 15 meter issue worked out I will also have 6 bands. I have two doublets made of #12 insulated stranded copper wire. One is a total length of 49' the half length is 24.5' each. The flat top portion is 19' each and the rest of the wire length is vertical= 5.5' directly to the tuner. The other is fashioned the same way where the total length is 36.8' the half length is 18.4' the flat top portion is 12.9' each and the rest of the wire length is also vertical 5.5' and again directly to the same tuner. The seperation is set to where the ends of the second doublet is sloped 8" below the longer doublet. I have a wide range T-match tuner and except for some problematic issues with 15 meter band I have been able to use this arrangement on 5 bands 10,12,17,20 and 40. With 15 meter being a little problematic. The two fanned doublets are located indoors on the ceiling and wall by 8" at end of shortest one. I will do some work with 15 meter band tomorrow. I do not really care which doublet or combination is doing the radiating per band selected, but will need more time to sort that out with some analysis, surfice to say I am making good contacts DX included, it is theory but it could be that I have succeeded in an interesting edz variant for the majority of the 6 bands with the aid of a wide range T-match tuner and direct connection to it. the vertical portion of the two doublets are 2" apart as they travel down to the tuner and most likely serve as balanced feed line with an unknowwn radiating contribution but never the less serve duel purpose to help establish the total length needed. Interesting yes. A single longer all band doublet would not work in this indoor situation. Breaking the rules with a 17 meter add on that is roughly a full size edz. Two antennas 6 bands indoors kinda nice. 73
 
RE: 6 Band Wire Antenna  
by ZENKI on April 15, 2009 Mail this to a friend!
So who will be our next antenna entrepreneur?

I am waiting for the mil spec version...

 
RE: 6 Band Wire Antenna  
by W2RI on April 15, 2009 Mail this to a friend!
N6RK wrote :
"While this antenna will get you on 6 bands with minimal stuff in the air, the bandwidth will be considerably narrower than conventional dipoles. ...It is definitely a compromise."
True, but sounds like a lot of fun for backpacking with a QRP rig.
 
RE: 6 Band Wire Antenna  
by W6WBJ on April 15, 2009 Mail this to a friend!
N4JTE wrote: "do any of you guys ever get on the air and actually talk with someone or do you spend your time playing expert on the internet?"

Actually, 'JTE, I thought the naysayers were being pretty kind to you by staying silent, but since you've started hurling insults, I'll respond honestly. Why do you think that another version of the fan dipole is technically significant enough to merit an article on eHam.net? I don't think your article offered anything useful or valuable, and that you are overly-impressed with your own silly "accomplishment". And you're insecure about it, to boot! I would NEVER put up such a stupid antenna. I've been a ham since 1960, and have tried enough fan dipoles to know that they work lousy compared to separate dipoles. All you've done is to suggest another kind of ribbon cable to use for such an antenna, but a *hit sandwich is STILL a *hit sandwich, no matter how you try to disguise it!
 
RE: 6 Band Wire Antenna  
by N3JBH on April 15, 2009 Mail this to a friend!
Mc Mastercarr sells what the call high voltage flat wire.
It can be had in many sizes and gauges. up to 16 Gauge 10 conductor. I also know you can get it in 100 foot long rolls maybe longer??? Never had a need for any longer than that. Jeff
 
6 Band Wire Antenna  
by KC8VKS on April 15, 2009 Mail this to a friend!
I have used something very simular to this for a couple of years. Mine does 80, 40, 30, 20, and 17 meters and uses 18 gauage solid copper wire that I buy in balk from Home Depot [or simular places]. I feed mine with coax with about 16 inches worth of beads at the feed point to make a 1:1 balum.

Without the beads, I would get some RF in the shack on some of the bands and that had a tendency to interact with the computers.

As mentioned, this is a fairly narrow bandwidth antenna system, which works fine for me, as I am only on the PSK parts of the bands. Ice and water will also effect it. Especially ice. A simple manual tuner would probably take care of that on the shack end, but I have not bothered to do that at this point.
 
6 Band Wire Antenna  
by W3KM on April 15, 2009 Mail this to a friend!
Nice article.

As mentioned it does not matter if the conductors are flat ribbon or twisted wires. They both work the same way.

Many of us have tried these antennas. They are cheap, easy to make and they do work on multiple bands.

But... they end up on the ground in the first ice storm - or strong wind.

Dave, W3KM
 
6 Band Wire Antenna  
by VY1PG on April 15, 2009 Mail this to a friend!
If anyone is interested in the wire used, I found some at this following website.

http://www.hobbylinc.com/htm/atl/atl312.htm
 
RE: 6 Band Wire Antenna  
by K5END on April 15, 2009 Mail this to a friend!
JTE,

I don't consider your comment an insult. Instead, I think it is a good and very relevant question.

It's a good, educational article and the antenna can be used for service.

Some of us are on the internet only during times when we cannot be on the air--like right now, when we are goofing off at work. Nohe HF antenna will quite fit in my downtown office, but at least I have big windows and we're about 100' up. :-)

I may have to try and load the miniblinds, surreptitiousy, sometime. That would be a great article.


 
RE: 6 Band Wire Antenna  
by NO6L on April 15, 2009 Mail this to a friend!
>by N3QE on April 14, 2009
>The all-band doublet is easier to construct, easier to feed, doesn't require trimming and pruning on multiple attempts to go up and down.

But it does require:

An antenna tuner with it's losses, and an expensive one at above a couple of hundred watts.

Has multiple lobes on different bands, many unpredictable without modeling software.

Requires open line feeder with all the standoffs, feedthroughs and other headaches.

Constant retuning of the transmatch when you QSY, even more than a vucuum tube amp.

>by N3QE on April 14, 2009
>If you really insist on believing that all antenna feedlines must be coax, you may very well be trapped into the fan dipole. Too bad for you. To me the concept that all feedlines must be coax is reminiscent of "CB thought" where low SWR is the only measure of an antenna. Believe me, it's an irrelevant measure if you use ladder line.

Trapped huh?

I can even bury my coaxial cable if I wish.

It took barely a couple of hours to tune my fan on 80, 40 and 20 meters. How many hours do you spend a year retuning your antenna tuner?

I saved a couple of hundred bucks by using a fan because I don't need a tuner.

On the contrary, I don't worry about VSWR in the least, I prune for minimum at the center of the band of interest and don't care about the 3 or 4 to 1 on the ends.

VSWR is also irrelevant for coaxial cable below 6:1, guess what a properly pruned fan delivers. Here, let me help, way less than 6:1.

If open feeder was is awesome, why did the military services stop using it, OVER 60 YEARS AGO!?

You have a very pretentious attitude and and unflexible opinion as to what other people should own or use.

So, who's trapped here? It seems you are, by the "Open Feeder Myth". Too bad for you. Now, read something about the subject and let's work on the attitude.

homepages.ipact.nl/~pa1are/tuner/reflections.pdf

de NO6L
/end of line
 
RE: 6 Band Wire Antenna  
by K1BXI on April 15, 2009 Mail this to a friend!
I made one of these for 40, 20 15 and 10 using 4 conductor TV flat rotor cable many years ago and it seemed to work fine for me at the time. That was 50 years ago at the peak of cycle 19. The propagation gods were very good to us at that time, so maybe that helped.

I don't think this antenna can be compared to a fan type multiband dipole. This is a parallel multiband dipole.

John
 
RE: 6 Band Wire Antenna  
by AB7E on April 15, 2009 Mail this to a friend!
W7NUW: "The all-band doublet will give a complex pattern of lobes and nulls depending on what band you're working. The fan dipole will give the typical double-broadside radiation pattern. Two very different things."


That isn't true. Obviously you've never modeled a fan dipole. The mutual coupling between elements causes all sorts of pattern distortion. Most bands end up being a cloverleaf, and the only band that shows a classic broadside pattern is the lowest frequency band. Try it and then come back and report what you found.

Dave AB7E

 
RE: 6 Band Wire Antenna  
by AB7E on April 15, 2009 Mail this to a friend!
K1BXI: "I don't think this antenna can be compared to a fan type multiband dipole. This is a parallel multiband dipole."


I'm curious what you think the difference is. Except for an extremely slight difference in the distributed coupling, there is no difference at all. All practical spacings between conductors for either configuration are small compared to a wavelength.

Dave AB7E


 
6 Band Wire Antenna  
by NO6L on April 15, 2009 Mail this to a friend!
Good article and decent directions. There are some things missed, though. A much easier way to tune a fan, maypole or ribbon antenna is to cut the elements about 5% longer that the bottoms of the CW sub-bands and trim back. And, you must always, without fail, start on the lower bands first.

Also, unless I missed it, you should have also mentioned a 1:1 current, coil or W2DU choke balun. Especially if the feedline length is relatively short for the lower frequency or frequencies or the shield is not grounded before entering the shack. You may get "Shack RF" and will get a distorted pattern, if that last one is important to you.
 
RE: 6 Band Wire Antenna  
by K1BXI on April 15, 2009 Mail this to a friend!
"I'm curious what you think the difference is"

For starters, all that dielectric between the wires as compared to air with the fan dipole and the fan dipole has much greater separation, especially at the ends, making each dipole more independent of it's neighbor.

John
 
RE: 6 Band Wire Antenna  
by AB7E on April 15, 2009 Mail this to a friend!

K1BXI,

On what do you base that conclusion? Gut feel doesn't count. Have you modeled a fan dipole with air separation and typical spacing between conductors? I have, and there is all kinds of coupling. You don't need a dielectric to couple fields ... magnetic coupling is every bit as important as capacitive coupling, probably more so for thin conductors.


Dave AB7E

 
RE: 6 Band Wire Antenna  
by K1BXI on April 15, 2009 Mail this to a friend!
Of course there is coupling. but it diminishes by the square of the distance. Am I not right?

I'm not saying that once this ribbon antenna is trimmed to a low SWR on each band it would work any worse than a fan dipole. Just that it will take a bit more time and fussing because of the dielectric constant of the ribbon material and the very closeness of the elements.

In that respect it will tune differently than a fan type. And yes, that is, in your words, my gut feeling.

I'm not sure that NEC can model this ribbon antenna easily and accurately.

John



 
RE: 6 Band Wire Antenna  
by G6NJR on April 15, 2009 Mail this to a friend!
>>>I share N3QE's worry about SWR-centrism.

You obviously dont care about your PA or you are a killowatt merchant modern solid state PA shut down on high VSWR so yes you NEED to worry about it .

Pete G6NJR

Nice article by the way i may even be able to get something like that in the air here not easy at all
 
RE: 6 Band Wire Antenna  
by N3OX on April 15, 2009 Mail this to a friend!
"You obviously dont care about your PA or you are a killowatt merchant modern solid state PA shut down on high VSWR so yes you NEED to worry about it . "

You're missing my point.

I'm not saying there's not a need to present a 50 ohm load to a transmitter designed for it.

I'm saying that if that is your only measurement of an antenna, you might be ignoring something more important.

All you need is a little matching to fix a non-50-ohm impedance.

73
Dan
 
6 Band Wire Antenna  
by W2MC on April 15, 2009 Mail this to a friend!
This is a VERY tempting design for a portable antenna (for FD, for a demo station, out camping with the Boy Scouts, etc).

Thanks for the great idea; and a use for all that 3 and 4-conductor rotor cable I got from radio shack a few years back (for about 50 cents a roll!).



Jon
W2MC
 
6 Band Wire Antenna  
by K7TCE on April 16, 2009 Mail this to a friend!
Great article Bob.

Hey guys, read carefully! It works 6 bands and costs $35. Duh, of course it is a compromise, and if it works at all it's a good one. What antenna (or fighter jet, set of golf clubs, or automobile) isn't a compromise between cost, complexity, and performance?
 
RE: 6 Band Wire Antenna  
by N3OX on April 16, 2009 Mail this to a friend!
"What antenna (or fighter jet, set of golf clubs, or automobile) isn't a compromise between cost, complexity, and performance?
"

For a given level of complexity and cost, there is a wide range of possible antenna performance.

Somewhere in that range, an antenna crosses the line between "reasonable compromise" and "bad design."

This antenna is not a bad design. It's a good compromise.

But that doesn't mean all antennas or antenna installations that have ever been designed are something that I'd consider a reasonable compromise. Some perform significantly worse than cost and complexity (and space and frequency coverage and whatever the rest of the criteria are) would allow.

This has very little to do with the current article, it's more of a general comment on the use of the word "compromise" in relation to ham antennas.

They're not all compromises. A lot of people OVER-compromise ;-)

 
RE: 6 Band Wire Antenna  
by M0ZJB on April 16, 2009 Mail this to a friend!
has anybody in the uk found anything to build this ant.
if so let me know please
fab article
cant wait to start on mine,and so what if ist not the best allband wire im certainly going to have fun trying
73 mark
 
RE: 6 Band Wire Antenna  
by K9MHZ on April 16, 2009 Mail this to a friend!
>>>>by ZENKI on April 15, 2009
So who will be our next antenna entrepreneur?<<<<


Probably MFJ.




 
RE: 6 Band Wire Antenna  
by N4JTE on April 16, 2009 Mail this to a friend!
Whew!! Back to the relative safe space of on the air contacts, appreciate all the comments, works for me.
Take care all.
Bob
N4JTE
 
RE: 6 Band Wire Antenna  
by KE5VUI on April 17, 2009 Mail this to a friend!
Very good article. I just noticed how quite a few people just dont understand the whole of the article written because the issue of strenght was addressed with the masonary string and tie wraps. I also liked the idea of using "trailer light wire" although it is a bit more expensive but of heavier gauge. Never mind the folks who always try to down a project because it doesnt have a big name or enough money spent.

73. Mike KE5VUI
 
RE: 6 Band Wire Antenna  
by W5WSS on April 17, 2009 Mail this to a friend!
NO6L please indulge us. As you stated especially when the feed line is relatively short with respect to the low bands causing more common mode issues when shorter than if it is longer? Are you suggesting that a shorter section of feed line is more problematic with respect to common mode than a longer one?
 
In Summary  
by N2EY on April 18, 2009 Mail this to a friend!
Is it the best HF antenna in the world? No.

Is it a compromise? Yes.

Is it a radical new idea? No.

How well does it work? About the same in efficiency and SWR as a plain half-wave center-fed-with-coax dipole.

How much does it cost? Author says $35, less with a bit of scrounging.

How big is it? Same size as a half-wave dipole on the lowest band.

Can you build it with common hand tools and are all the parts readily available? Yes and yes.

Can it be adapted for other bands and different parts of the bands? Yes and yes.

Was the article clear and well written? Yes.

73 de Jim, N2EY

 
RE: 6 Band wire antenna  
by K8NDS on April 18, 2009 Mail this to a friend!
Great article for a compact lot antenna, I used these types of antennas back in the 70's. I worked the world with 100 watts. I read these articles for laughs; it never ceases to amaze me how some people have to tear apart everyone’s articles. Instead, why don't you use all that pended up energy to write an article to inform new bees of the correct way to do it? It was obvious to me that this article was written for people with limited funds, limited property and ease of getting a signal on all bands. Not all hams care about pattern or antenna modeling as long as they can radiate a signal. In all reality if you can hear it and your antenna radiates, you can probably work it. Not all of us look at this hobby as a competitive sport; most of us don’t care about contests or having the best signal on the air. If you feel the need to tear apart an antenna that really doesn't work, try something like the Maxx-Comm (Dummy Load Antenna); at least the 6 band wire antenna actually radiates.
Lighten up guys; you don't have to be arrogant and try to flaunt what YOU know! Buy the way, this hobby is called AMATEUR Radio, not commercial.
 
RE: 6 Band Wire Antenna  
by W5WSS on April 18, 2009 Mail this to a friend!
I could not make the two long indoor fanned doublets connected to a common tuner with open wire line to work even remotely as good as compared to conventional 1/2 wave doublet's anywhere, let alone on 6 bands, the two were coupling destructively I some what expected it. I hoped the indoorness of them and along with some unknown mutual coupling of other nearby conductors was something that I stumbled on but not to be. I will try a 1:1 current balun and 52 ohm coaxial line via two resonant dipoles max for a fan affair should work ok.73 to whom it may concern
 
RE: In Summary  
by N4JTE on April 18, 2009 Mail this to a friend!
N2EY tnx for summarizing my same conclusions, appreciate that, again, I am on the air, 40 and 80 every night of the week on the OMiss net frequencies.
Also on 40 most afternoons here in NY anywhere around 7125 and up from 5pm or so, any takers?
I build antennas to communicate on the radio, I only throw articles out on eham to help other antenna experimenters with what I've learned. Sure would like to meet some of you on the RADIO as opposed to the internet.
With respect,
Bob N4JTE
 
6 Band Wire Antenna  
by N6JSX on April 20, 2009 Mail this to a friend!
I've been making multi-element inverted "V" (I-Vee) antennas for years.

The hardest problem is tuning the antenna especially on 160/75/40m, due to the long wire lengths.

Then the next question has been - due you start your tuning from the longest element working your way down to the shortest element or vice versa? How do the elements interplay with one another affecting tuning?

Big problem I've found is the interplay of the elements using the type cable this article uses - never was able to make all elements work. Then add to this my experience of using soft copper wire that significantly stretching due to wind loading overtime will eventually de-tuning your longest elements. (this type of cable could be used in an attic or under the house eves but not free standing in the wind)

Then add to this the reactance of the elements is vastly different when mounted in the air verses on/near the ground during the tuning process.

I overcame some of this by using a copper clad steel wire for the longest element (hardly any stretching - check out RadioWorks.com or galvanized steel farmers electric fence wire - just not as efficient but real strong). Then I created spacers using plastic decking planks (table saw and drill press) putting all wires at least 3" apart (20MAR08, I posted my "how-to" make spreaders on eHAM). For all other elements I used common/clearance 12-16AWG wire from any cheap hardware store.

I strung a pulley/rope on my tower to hoist away getting the I-Vee as near to the element apex angle and ground affects as will be used. Then I started tuning from longest to shortest element bands.

I love I-Vee's - cheap to build and very efficient to use. But NO two optimized I-Vee's are the same (nor can be mass produced) that do not require tuning to YOUR station installation. Near yes, optimal NO - to many variables (why to you think Alpha-Delta 160/75/40m antennas come with such long elements, just for CW - nope), height above ground, angle of the elements, interplay with tower/mast/roof, 120degree apex is optimal for 50 ohm coax - any other angle will require tuning.

Also another problem with I-Vee's is on 160/75m SSB. 75m being 3600-4000 equates to a single element length difference of 6.4' - just to much length not to use an antenna tuner. 160m being 1850-2000 equates to a single element difference of 9.2' - again just to much length not to use an antenna tuner on a single element per band antenna.

One of my projects is to build an I-Vee using 4 elements (much like a cage antenna). With elements on 3650, 3750, 3850, & 3950 - putting the wire length difference between elements ~1.5'.
I also intend to build an I-Vee using 3 elements with elements on 1850, 1900, & 1950 - putting the wire length difference between elements ~3.2'.

See what I can come up with - my goal is to NOT need an antenna tuner! Here is one of the last frontiers of HAMdom - antenna building!

Kuby N6JSX /8
http://groups.yahoo.com/group/RDF-USA
http://groups.yahoo.com/group/HAM-SATs

 
RE: 6 Band Wire Antenna  
by PULLRAFTT on April 20, 2009 Mail this to a friend!
Great article! We had a real nice weekend here so I decided to use some of the wire I have been hoarding for several years and give it a go. I had pretty good results on all bands. I think it needs some work as I threw it together pretty fast, but so far I am happy with the results. The next nice weekend we get I will take it down and tweak it a bit.

Thanks again.
 
RE: 6 Band Wire Antenna  
by N4PGW on April 22, 2009 Mail this to a friend!
">>>>by SM4INV on April 14, 2009 Nice article, will try it but very frustrating to find that your m's does not mean meter but MHz....
72/73 de p-a, se4a/sm4inv<<<<


3.95 "meters" for a 75 meter band antenna?? I mean, wasn't it obvious that "M" meant "MHz"? Yikes, whatever. "

I think what SM4INV was getting at was that the OP didn't post the final lengths, instead he posted the frequencies he achieved.

 
RE: 6 Band Wire Antenna  
by N4PGW on April 22, 2009 Mail this to a friend!
"If you really insist on believing that all antenna feedlines must be coax, you may very well be trapped into the fan dipole. Too bad for you. To me the concept that all feedlines must be coax is reminiscent of "CB thought" where low SWR is the only measure of an antenna. Believe me, it's an irrelevant measure if you use ladder line. "

I think you missed the point. It is cheap, no tuner required, and easy to build. "CB thought" is to buy everything and brag about how much better their station is over another. Hams think about how to communicate using whatever is available and to be creative with unconventional materials. If anyone sounds like he has "CB thought" it isn't the OP!

 
RE: 6 Band Wire Antenna  
by N4PGW on April 22, 2009 Mail this to a friend!
"Great article. this is the essence of the fan dipole, yet he never mentioned the word once, bravo. "

I rather think this is not a fan dipole, but a parallel dipole. I believe it derived from the fan, if not the other way around. The difference is that the fan dipole has elements going out in different directions like the blades of a fan. The parallel dipole keeps the legs close together basically evenly spaced for the entire antenna.

The fan dipole is easier to tune as there is no interaction between the wires, but the parallel dipole can be easier to tune if they are spaced 6 inches apart or so. Parallel dipoles take up less real estate and are sometimes more easily seen than the fan or single-band dipoles. However, a parallel dipole with 4 inch spacing between 80, 40 and 20 meter elements will have a tremendous bandwidth advantage on 40 and 80 over the single band dipole.
 
RE: 6 Band Wire Antenna  
by N4PGW on April 22, 2009 Mail this to a friend!
N4JTE: "I have a 60ft. high 165ft. "doublet" center fed with ladderline to the shack. Great antenna on 80 and 40 but would not load up below a 3 to one on 15,17 or 10 meters using a ATR-30."

You might also consider trimming the ends of the wire. I had a 150 foot that worked all HF bands except for one WARC band (I don't remember which, i think it was 17m). I have seen similar antennas trimmed a little to get them to work all bands. I did not trim mine, but I wasn't concerned with that band at the time.

 
RE: 6 Band Wire Antenna  
by N4PGW on April 22, 2009 Mail this to a friend!
N6RK wrote :
"While this antenna will get you on 6 bands with minimal stuff in the air, the bandwidth will be considerably narrower than conventional dipoles. ...It is definitely a compromise."

Not necessarily, I have a lot of experience with parallel dipoles. In my experience, the bandwidth on 40 and 80 is much greater than on single wire antennas cut for the same frequencies. I am guessing that the close proximity of the shorter wires gives the antenna the appearance of a fatter element. Mine were spaced 4-6 inches apart so this antenna may not have the same results, but it may still be a fair bandwidth given the width of the group of wires.
 
RE: 6 Band Wire Antenna  
by N4PGW on April 22, 2009 Mail this to a friend!
Bob,

I am very glad to see you build this antenna. It is not a new idea, but over the years I have heard about them, then heard how they can't work, but I have not actually seen evidence of one working until now.

I was, at first, surprised that you didn't include the final dimensions of the antenna, but then, thinking about it, I rarely felt like measuring my antenna when I finished.

I have no experience to speak of with inverted V antennas except to help install two of them in 30 years of being licensed. I have a lot of experience with dipoles and parallel dipoles. I have not tried the ribbon dipole, but I am interested in doing so, much more now than before I read this. As one reply put it, this looks like a good field antenna for QRP portable operations.

73 for now
hope to see you on the air.
Buck


 
6 Band Wire Antenna  
by NZ4O on April 22, 2009 Mail this to a friend!
The fan dipole made out of parallel ribbon line is a good beginner antenna to get one on the air. However due to the closeness of the wires and therefore interaction, plus velocity factor issues having to do with the inulation, it's nearly impossible to get the antenna to resonate where you want it on each band. I tried this antenna 20 years ago and it was a poor performer with window line and coax compared to individual dipoles cut for each band.

I then tried a fan dipole made out of seperate #14 wires. The interaction was such that it was nearly impossible to get the antenna to resonate where I wanted it on each band. I ended up dumping the coax and going with 450 ohm window line to a Johnson Viking Matchbox balanced link coupled antenna tuner and the antenna worked better.

I then tried the tried and true all band antenna with one element cut for the lowest band of operation and fed it with 450 ohm window line. I once again used a Johnson Viking Matchbox balanced link coupled antenna tuner and the antenna worked better still through ten meters.

Finally I went with a horizontal loop cut for 80 meters (288 feet) and fed it with 300 ohm window line to a Johnson Viking Matchbox balanced link coupled antenna tuner.

This antenna actually blew away the above antenna's by far. The antenna was more quiet and produced allot of gain on 30-10 meters.

This is the politically correct truth as the laws of physics are the same everywhere on Earth. Of course everything is relative and one man's trash is anothers treasure.

73,
Thomas F. Giella, NZ4O
Lakeland, FL
 
RE: 6 Band Wire Antenna  
by VE7OTH on April 23, 2009 Mail this to a friend!
I agree... this guy wrote a great article and put lots of work into it, we should all be thanking him, not bitching because we think "m" means metres not mhz...sheeesh

73's
Jennifer
 
RE: 6 Band Wire Antenna  
by 5R8GQ on April 25, 2009 Mail this to a friend!
Thanks to the author for this informative article. This looks like a good portable antenna. I have been using a 4 element homebrew "fan" (well, technically parallel) dipole for camping use for many years. But mine uses 18 gauge solid wire and 18" x 1/2" PVC pipe "spreaders. And a choke balun. It works pretty well for what I want to do out in the woods. But the solid wire and spreaders make it a pain in the tush to pack and unpack. Lots of straightening out and removing the kinks before putting up. (But is HAS lasted a long time!!)

I had always believed that using ribbon cable wouldn't work well because of capacitive coupling between the elements but apparently not in this case. This antenna would be a LOT easier to pack, put up, and take down. And that's a GOOD thing. Because I've found that the more time I spend at a campground putting up my antenna, the more 8 year old kids come up to me with their finger up their nose and say "Whatcha doin' there, mister?" Bwahahaha!
 
6 Band Wire Antenna  
by VK4KX on April 29, 2009 Mail this to a friend!
Like he said "he Lazy" make M for MHz not M for Measure, must be precise or some peoples can gets a bit confused.
Good article though, I'm always interested in antenna articles.
73
 
6 Band Wire Antenna  
by N6FB on April 30, 2009 Mail this to a friend!
I used to make antennas like this back in the 60's. I used transmission sized 300 ohm twin lead, and taped three lengths together back to back. the six wires, all cut to length as discussed in the article, fed in parallel with 50 ohm line, worked very well on all bands with about 300 watts, which is all I had at the time.

It is an effective, "quick and dirty" antenna, but it wound up as my only antenna for several years.
 
RE: 6 Band Wire Antenna  
by WA2JJH on April 30, 2009 Mail this to a friend!
I wish remote WX proof feed point ATU's were inexpensive enough. A TX tuned antenna base mounted ATU is overkill!!!!!!

Perhaps I will homebrew a simple tapped inductor/trimmer cap tuner.
Should work.

If you follow the dimensions for each band, and minimize cross coupling, you will always be in the ballpark.

Perhaps should just cough up $200 and get the cheapo MFJ antenna analyser.

It is still hard to get more than 100khz bandwidth on 80M.
 
RE: 6 Band Wire Antenna  
by WA2JJH on April 30, 2009 Mail this to a friend!
I wish remote WX proof feed point ATU's were inexpensive enough. A TX tuned antenna base mounted ATU is overkill!!!!!!

Perhaps I will homebrew a simple tapped inductor/trimmer cap tuner.
Should work.

If you follow the dimensions for each band, and minimize cross coupling, you will always be in the ballpark.

Perhaps should just cough up $200 and get the cheapo MFJ antenna analyser.

It is still hard to get more than 100khz bandwidth on 80M.
 
RE: 6 Band Wire Antenna  
by WA2JJH on April 30, 2009 Mail this to a friend!
I wish remote WX proof feed point ATU's were inexpensive enough. A TX tuned antenna base mounted ATU is overkill!!!!!!

Perhaps I will homebrew a simple tapped inductor/trimmer cap tuner.
Should work.

If you follow the dimensions for each band, and minimize cross coupling, you will always be in the ballpark.

Perhaps should just cough up $200 and get the cheapo MFJ antenna analyser.

It is still hard to get more than 100khz bandwidth on 80M.
 
RE: 6 Band Wire Antenna  
by K5MO on May 4, 2009 Mail this to a friend!
Having built several parallel element dipoles, I found them extremely fussy (or impossible) to tune to resonance unless the elements are separated at the far ends by several feet. At that point, they behaved more like independent wire dipoles.
 
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