I use one of these antennas. It proved to be much better than a normal G5RV. I have also tried a 60m dia loop and various verticals, but the measured performance of the ZS6BKW was either better or in the worst case equal to the other antennas. Too many antenna recomendations are not based on fact, so don’t believe everything you read. G5RV’s seem to have a bad reputation, so you’ll get better signal reports if you say you are using a open wire fed doublet !

The key things to watch when constructing the antenna are:-

get the length of 450 ohm open feeder correct. The velocity factor of the stuff I used was not as advertised. I measured it with an antenna analyser and cut it to the correct length.
Use a good 1:1 balun at the end of the 450 ohm feeder. This drastically reduces the receive noise level on 160m and 80m. Note that a few turns of coax do not make an effective balun. You need plenty of ferrite.

See http://www.geocities.com/martin_ehrenfried/HFantennas.pdf

I’m now working on a remote switching box to strap the feeders together for transmit on 160m. Tests proved that this gave a 20dB improvement over the antenna running in it’s balanced configuration on this band.

Regards,

Martin