[Elecraft] Power oscillation problem (KPA500+KAT500)

[Andy Durbin]

"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