View Full Version : FM Log-Yagis

08-03-2013, 02:34 PM
I've posted a writeup for three FM log-Yagis here:


I designed these antennas to minimize rear response over the whole 88-108 MHz FM band. They have very low backlobes but relatively low forward gain. I believe most FM DXers are limited by interfering signals, not by lack of signal strength. You can compare their forward gain and front-to-worst-backlobe ratio with those of other antennas here:


Each of the designs requires a phasing line. I specify 1/8" aluminum wire spaced 1/2". I thought fabricating this line would be the most difficult part of building one of these antennas. But Mike-CT had a better idea. He built an earlier design using parts salvaged from old antennas, include the phasing line. The design he built specified 1/8" wire spaced 1". Turns out the impedance of Mike's salvaged phasing line isn't that far from the impedance of the specified line! The writeup includes a photo of Mike's antenna.


08-04-2013, 11:19 AM
Thank you for all your work on that site. It'll come in handy for me as I plan an FM setup over the next year.

08-07-2013, 11:49 AM
Vertically polarized log-Yagi stack:


Gain and pattern comparisons: