[CQ-Contest] 40m to 20m interference

[john at kk9a.com]

You're not asking too much. One of my homebrew 20m beams has a 40m  
OptiBeam interlaced on the same boom and at 100 watts there is no 20m  
interference at all except right on the harmonic. Make sure that you  
are using quality coax, good chokes at the antennas and perhaps try  
better bandpass filters or converting your verticals to monoband  
verticals.

GL,
John KK9A


William Hendrick N0AC wrote:

I have a lot of interference on 20m when TXing on 40m even with BPF on  
each K3 running 100w. A 23' shorted stub at the 40m rig doesn't seem  
to help. Both antennas are Butternut verticals about 150' apart. Am I  
asking too much for the filters with the same antenna polarization and  
spacing?

Bill, N0AC