Is it any good? Should you use one?

Before I talk about the G5RV antenna, I'd like to talk about Lou, G5RV the Radio Ham.

I was fortunate to meet Lou. Not long after I got my licence I went to a G-QRP club event near Oxford. It was your typical Ham Radio rally, traders selling stuff, individuals selling stuff, beer tent, some lectures and a demonstration station.

When I arrived the main hall was really busy. I hate crowds with a passion, so I got a cup of tea from the refreshment tent and went and stood with a group of people outside who were talking about antennas.There was an elderly man, neatly dressed in a Royal Signals Corp blazer. He was chatting away about antennas, offering advice and answering our questions. After a while I noticed he had a call sign badge. Lou G5RV. I was hanging out and chatting with the guru of antennas. Cool! Not that cool was used in that way back then. Groovy man!

While I have your attention: Hardly anyone wears call sign badges in the modern era. Back in the day we all did. You could be standing right next to some one you have worked loads of times and not know who they are. But if they had a call sign badge...

I am on a one man mission to bring back the call sign badge.

Back to Lou and his antenna. The G5RV. Is it any good? Should you have one?

Lou designed the antenna to fit in his garden. 105 feet dipole. Then open wire ladder line to act as a transformer. Then 72 Ohm balanced feed line to the transmitter. That transmitter would have had a balanced output at 75 ohms. The tuning of the valve output would also have acted like an ATU. That's nothing remotely like a modern set up!

The G5RV is also promoted as a multi band antenna. Lou wanted 20 metres, Anything else was a bonus.Back when Lou designed his antenna we had way fewer bands.

You can see where this is going...

Personally I would not recommend a G5RV. However I would recommend it's cousin the ZS6BKW, and I have one as my main HF antenna.

So what's a ZS6BKW? It looks just like a G5RV, a dipole, a length of ladder line as a transformer, then a 1:1 Balun, then 50 Ohm coax to the radio. The difference is in the dimensions. It's a slightly shorter dipole, and a slightly longer transformer. The upshot of this is you will get a good match on most HF bands: 40, 20, 17, 12, 10. I use a manual ATU to work 30 and I leave that ATU permanently tuned for 30, switching it out for other bands. 15 does not tune. I have thought about putting up a dedicated 15 dipole but so far I haven't done so and I don't miss 15 so that's never likely to happen.

If you are scratch building a G5RV you might just as well make a ZS6BKW. If you are buying one ready to go then buy a ZS6BKW. That's what I did.

In practical use if you have a G5RV you will need a tuner for most bands. If you have a ZS6BKW you will need a tuner for two bands. (30 and 15) If you are not into digital or CW then 30 won't interest you so it's just 15 to accommodate. You could use a tuner, but a dedicated dipole would be cheaper.

My other antenna is a non resonant long wire. This is my 160 and 80 antenna, and I also run a WSPR beacon on it when I am not using those bands. Don't knock a non resonant antenna. It will have an impedance of about 450 ohms, so a 9:1 transformer will give 50 ohms. The compromise is in the ferrite material you choose for the transformer. This is also true for an EFHW. You have to pick, the lower bands or the higher bands, you can't have both. It'll work on all bands but with reduced efficiency.

Best Wishes
Ron
G4LMN