Topband: 2nd harmonic suppression

[Tom Boucher]

I had a similar problem to ZS1REC's with a high 2nd harmonic output from my amp and a report on 80m from Norway while on topband! 

Like many on 160, I use an inverted 'L' antenna which was matched with a high -pass 'L' network, series C and parallel L, not good for harmonic suppression. I changed this to a low-pass 'L' matching network, series L and parallel C, and the problem went away.

73
Tom G3OLB