"I should be able to fix the problem with better decoupling and/or choking of the breakout box connections."
Problem fixed by adding a 0.01 disc ceramic caps on each of the 4 RCA keyline jacks on the breakout box. I should have included them when I built it. Interesting problem though and all sorts of nasty possible causes gave way to a very simple one. Why didn't I see this problem earlier? My log shows I have only been on 40 m twice in the last two years. A year ago I had a new roof mounted heat pump installed. The antenna runs near ducting that was changed and the installers broke one antenna support that I have not repaired. My attic is a hostile work environment and best avoided if possible. 73, Andy, k3wyc ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com