Are all G5RV'S the same?

[GM4WIE]

Helo all I notice that the dimensions of G5RV antenna feeders both 300 ohm or 450 ohm seem to differ by sometimes 2ft yet the elements 51ft each for a full size remain constant. I realise that the velocity factor comes into play but what is correct?
Rgds
Charles
GA4WIE ***/ GM4WIE

***special Scottish prefix until the end of Nov 2009

[NN4RH]

Helo all I notice that the dimensions of G5RV antenna feeders both 300 ohm or 450 ohm seem to differ by sometimes 2ft yet the elements 51ft each for a full size remain constant. I realise that the velocity factor comes into play but what is correct?
Rgds
Charles
GA4WIE ***/ GM4WIE

***special Scottish prefix until the end of Nov 2009

You basically answered your own question. The velocity factor comes into play. The parallel line feeder should be electrically 1/2 wavelength on 20meters, around 33 feet. The velocity factor of 300 ohm twinlead is around 0.85 and that of 450 window line around 0.95, so the actual physical lengths will be around 28 and 31 feet respectively.

[GM4WIE]

Thannks but I have come across feeders for 300 ohm and 450 that are much shorter than the values you mention.
rgds

[NN4RH]

Well, I can't explain that. An honest -to-gosh G5RV is 3/2 wavelength on 20 meters and has a 1/2 wavelength (electrical length) of parallel line before it transitions to coax the rest of the way.

I suppose someone might try other lengths of the parallel line section to try to manipulate the SWR on other bands for multiband use. But then it's technically not an "honest" G5RV.

[GM4WIE]

Thanks
Rgds

[W4PG]

I think it's time to put the G5RV to rest. WAY too many issues with it and WAY too many other wire antennas (including, GASP! Dipoles!) that work equally well without all the "issues."

[GM4WIE]

No I don't think so just asking simple questions? Free speech and all that isn't that what you are famous for?
Rgds

[KB0DV]

I experimented with the G5RV when I starting using HF, both the 450 ohm and 300 ohm versions. My simple, homemade dipoles played better everytime.
The G5RV never made sense to me. It has to be the crappiest "multiband" antenna that has ever been mentioned as such. I've read many articles about the G5RV and in my opinion, it's a poor choice. Replace it with dipoles. I don't have the room for a dipole for every band so I have just 2 dipoles... 1 for 20 meters and 1 for 40 meters.
Dave

[NN4RH]

Like many others, my first HF antenna was a G5RV. I think when someone is new in the hobby the idea of a single "all-band" antenna for $49.95 is appealing.

After using it for awhile and thinking about it some . . . I cut off the coax and the "balun" and added enough twinlead to go directly to my widerange tuner. Much better results.

[K4NIN]

Helo all I notice that the dimensions of G5RV antenna feeders both 300 ohm or 450 ohm seem to differ by sometimes 2ft yet the elements 51ft each for a full size remain constant. I realise that the velocity factor comes into play but what is correct?
Rgds
Charles
GA4WIE ***/ GM4WIE

***special Scottish prefix until the end of Nov 2009

Another variation in size would be the ZS6BKW (G5RV)... About 93 feet across, with a longer twinlead section. Mine is about 40 feet. Seems to give more bandwidth... Google it...Cheers....

[WE4AU]

I think it's time to put the G5RV to rest. WAY too many issues with it and WAY too many other wire antennas (including, GASP! Dipoles!) that work equally well without all the "issues."

Yeah...what he said, and KR0V and NN4RH said too.

And it's not a free speech thing...it's a better antenna thing. :cool:


Regards,
-Bruce

[G4ILO]

I think one of the reasons many find G5RVs don't work very well is that they feed them with co-ax plus very often a balun. Because the G5RV is not a 50 ohm match a lot of loss occurs in the co-ax and balun.

A better option is to extend the ladder line "matching section" all the way into the shack and tune it with an ATU capable of matching balanced antennas. Then what you have is a doublet, which is generally regarded as a pretty effective antenna.

[K5PO]

I always assumed the G5RV was miserable as it is always being put down. That made this article an interesting read. I've never used one myself, but it gained a little respect here.

http://www.eham.net/articles/21682

[K4NIN]

I always assumed the G5RV was miserable as it is always being put down. That made this article an interesting read. I've never used one myself, but it gained a little respect here.

http://www.eham.net/articles/21682

ZS6BKW (G5RV), with cheap RS 300 ohm twinlead, RS speaker wire for the elements, held up with 3 pieces of electrical conduit at about 27 feet...

PSK31 below with 3 watts on my IC-738... 8100km
seems OK for me...

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NAME Robert Robert,
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TX> 7 Apr 2ØØ9 Ø3:14:24 UTC
9a4rc 9a4rc de K4NIN K4NIN
Thanks for the call. Your RST is 599 599. My name is John John, QTH is Jacksonville, Florida USA Jacksonville, Florida USA in EM9Øei [0.0° 0.0m] EM9Øei.
currently running 3 watts ....3 watts.....qrp qrp qrp!!!
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RX> 7 Apr 2ØØ9 Ø3:15:25 UTC
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My Paper QSL card is 1ØØ%tohure via bureau...
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TX> 7 Apr 2ØØ9 Ø3:16:4Ø UTC
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station: rig IC-738, power 3W, software Ham Radio Deluxe, antenna zs6bkw at 8 meters high.., Signalink USB, locator = EM9Øei [0.0° 0.0m].

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BTU 9a4rc de K4NIN K
RX> 7 Apr 2ØØ9 Ø3:17:29 UTC
Xo.Good luck J, 73' BYE from C?K4NIN DE 9A4RC are SK ..
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[AE5RC]

To strickly answer the question....no.

I think Mr. Varney's antenna was a 3/2 wave designed for 14.150 mhz. It was fed with 600 ohm open wire feeders (best I can tell from what pictures I have seen and articles read). The models we have today are (I suppose) based on the design but not all are the same. Look at WA2NAN's True-Talk antenna (called G5RV) compared to what MFJ markets as a G5RV, look at Antennas and More G5RV designs...none of these are apparently the same but all are called G5RV's. They will all do the same basic thing....get on multiple bands with the aid of a tuner.

I have made several wire antennas over the years and they have worked pretty well. One in particular was a windom design but in no way was it a real windom antenna as described by Loren Windom. It worked and as a matter of fact I talked to the ham I built it for the other evening. He was at his lake home and he uses that antenna as his wire at his vacation location. I recall reading an article by Lew McCoy (sk) about the Real McCoy Dipole. He mentions feeding a random length dipole with open wire, 450 or 300 ohm wire to a tuner and having a good antenna. He also said in that same article to avoid a length of 102 feet "because you have a G5RV and not a Real McCoy Dipole antenna". I guess that is the basis for my answer to the question, "Are all G5RV's the same?" I'll stick with no, they are not.

73

[G0GQK]

They'll make 'em any size you fancy ! There are antenna manufacturers making G5RV's from 93 ft long to 204 ft long. There have been more variations of this dipole than any other antenna that has ever been invented, by amateurs from all over the world !

Has anybody ever wondered why ?

G0GQK

[G3TXQ]

I think one of the reasons many find G5RVs don't work very well is that they feed them with co-ax plus very often a balun. Because the G5RV is not a 50 ohm match a lot of loss occurs in the co-ax and balun.

A better option is to extend the ladder line "matching section" all the way into the shack and tune it with an ATU capable of matching balanced antennas. Then what you have is a doublet, which is generally regarded as a pretty effective antenna.
Julian,

I agree that keeping the coax section short - even making it zero - is a good idea. But it's not true that a lot of loss occurs in the balun if you use one; in a 1:1 current balun the losses should be negligible.

73,
Steve G3TXQ

[PA1ZP]

Hello everyone

Normaly every G5RV has to be the same otherwise it wouldn't be a G5RV.

There is a ZS6BKW and there is a G5RV junior (half version)

The problems with these antenna's often accur due to ground effects and to effects of other electrically guiding "things" close around the G5RV.
The influences of different ways of hanging and the different heights of these antenna's will influence the impedance on the different bands and the way that the radiation pattern will be.

In fact nobody has the same surrounding the same ground effect, therefore almost everyone will have their own slightly different working G5RV.

Allmost 50% of the british amateurs on 40M use a G5RV, they all can't be wrong.
In fact a G5RV if properly placed is a very decent and cheap antenna.

You cant blame the antenna for to high expectations of the amateur and or being wrongly placed or build.


73 Jos PA1ZP

[VE3PTC]

i think all hams in the uk start off with the g5rv ! however, i have always thought that its an expensive way to make/ buy, a somewhat multi band antenna. as suggested in earlier posts, much better to feed with balanced feeders, and tune at the shack end. far lower loss, and better performance all round. any reasonable lengh of wire, and whatever lengh of feeder you need, and you can build one for next to nothing.
as a side bar, has anyone looked at the G5IJ end fed monopole ? quite an interesting antenna.
73 de bob. ve3ptc/gm0ley

[W0GI]

I have to agree that the G5RV is not a top choice. It is an interesting design, and I used one in the 70's when I got licensed, feeding it from a Drake TR-4C.

The lowest SWR I got was on 20M at about 1.8:1. The other bands were 3-4:1. Not very good, but the tube finals on a old Drake didn't mind too much, and it did work ok.

But then one snowy night, I fried the Balun with the old Heath SB-220. After that, I did some research, and found a nice used 3KW tuner with a roller inductor. Then I ran 450 ohm ladder from the center insulator of the 51' legs into the tuner in the shack.

It worked much better then the G5RV.

In my opinion, a manual tuner with a roller indicter is a great investment. I read lots of reviews about auto tuners with burned relays, and how long they will last. A 3KW NYE Viking tuner will outlast all of us. And it isn't that big a deal to tune, if you make a sheet of tuner settings for each band. Look at the sheet, turn the dials to the numbers, and you are tuned.

At present, I have an SG-230 coupler tuning my 130' doublet. It is quick, but it will probably go south at some point in the future, and I will be pulling the old 3KW tuner out of the closet, that I bought used 30 years ago, to do the job. :)

Since the G5RV needs a tuner with solid state transmitters anyway, I really wonder what good it is. Just buy a good external tuner, and forget about it.

If you want a wire antenna that performs, a Carolina Windom is a real good choice.

I have good luck with the doublet, and the R7000 vertical. I really don't miss the tribander at the old QTH too much. I still can work the stations I hear.

[AC0FP]

Isn't the G5RV antenna what was previously known as a 20 meter EDZ (extended double zepp) for twenty meters?

[G8WWD]

I think it's time to put the G5RV to rest. WAY too many issues with it and WAY too many other wire antennas (including, GASP! Dipoles!) that work equally well without all the "issues."

"Issues"? What issues are you talking about for goodness sake? Build a G5RV as it was originally designed by the man himself and you have a great antenna. Mess around with the dimensions, spec, etc. and you mess with the performance and create "issues"!

The G5RV was designed to be 51ft per leg on the top element and 34ft of 300 ohm feeder at right angles to the top element before you connect it to the co-ax. That formula works perfectly well if you build it correctly and even works well as a half size, albeit not well on 160m, with 25.5ft per leg and 17ft of 300ohm downfeed. My G5RV works superbly with an SWR maximum which is less than 1.2:1 without the need for an ATU and pulls in DX far better than verticals and many other antennas that cost me a fortune.

The rules are simple. Build a G5RV to the spec originally published by G5RV himself and you will have a great aerial that works well. Mess with the specs and you will have "issues" that are nothing to do with G5RV's design, but introduced by your own messing with the G5RV specs!!!!

G8WWD (Licensed in 1983 and been using a G5RV since the 1960's when I was an SWL!!!!!)

[KB9HGI]

yep just what G8WWD said! I agree I have had several of these over the years and always worked great for me. Everytime I turn the radio on no matter what band I always hear someone saying they are useing a G5RV.

[KE7PMX]

The rules are simple. Build a G5RV to the spec originally published by G5RV himself and you will have a great aerial that works well. Mess with the specs and you will have "issues" that are nothing to do with G5RV's design, but introduced by your own messing with the G5RV specs!!!!

G8WWD (Licensed in 1983 and been using a G5RV since the 1960's when I was an SWL!!!!!)

Quoted for truth...

Im glad to see someone else that gets it!.

[W5MEJ]

The rules are simple. Build a G5RV to the spec originally published by G5RV himself and you will have a great aerial that works well. Mess with the specs and you will have "issues" that are nothing to do with G5RV's design, but introduced by your own messing with the G5RV specs!!!!


Which spec was originally published? Varney described several different versions of the feedline and matching section from what I have read. I thought his original version was just a 3/2 wave doublet on 20m, fed with open-wire feedline.

I've also been told that the antenna G5RV used most often was a 204 ft. version, again fed with 600 ohm open-wire feedline all the way to the transmatch.

W5MEJ, Chuck