[CQ-Contest] radio interference

[Marco Spalluzzi]

Hi Rick, you can add the 15m station a stub made with rg213, 23 ft long,
shorted at the end.
That length is ok for any 0.66 vf cable.
This is 1/2 wl on 20m, and 1 wl on 10m, so it will create a notch of about
25 dB on both 10 and 20m.
It should produce the same effect of a 25 dB reduction of the tx signal from
the 20m station.
It could cause a little mismatch on 15m, but if it were me, I would give it
a try.
20m harmonic will not fall on 15m band, so, there's nothing you can do on
the 20m station; it's not an harmonic related problem.
What you need is eliminate fundamental overload from 20m to 15m.
Bandpass filter worked, as you wrote; stub should increase this effect.
Hope it helps.
Marco - IK2XSL.