biplane antenna

My Bi-Plane Antenna for 20 Meters


I have recently completed a Bi-Plane antenna for 20 meters, tuned it up, and put it on the air. Resultsd indicate that it is working ... pretty well for a 3-feet long dipole-type antenna at 22 feet up. I have made contact with IL TX AZ AL MS FL NC PA NH amd DL in Germany. I wanted to determine the efficiency of this structure. To that end I have done A/B comparisons on signals received with a homebrew wire half-rhombic at 22 feet apex. There was essentially no difference. I also compaed the signal strength at my 2m beam about a half-wave away from each. Essentially no difference. That's good. At least the BiPlane is not really lossy. The bandwidth is about 500 kHz at 14 MHz. I'll get some exact numbers when I re-center it and re-tune it next week. I had only tuned it up in the lab with all the reflections there ... it"s off by 500 kHz from band-center and 2.5 VSWR.

I have a set of pictures of the 20m Bi-Plane with a 2m version above it accessible here at (1), (2), (3), and my 70-foot long half-rhombic (4).

I have also included an e-mail that I dashed off to N2PK when he asked about the antenna.

More to come ...
John Matz KB9II