[Elecraft] Power oscillation problem (KPA500+KAT500)

[Rick NK7I]

I'm glad you found the cause and a fix.

I'll add that, in my experience, 40M is always the most problematic band 
for causing RFI problems.  In a vehicle or home, it seems that a LOT of 
'stuff' is sensitive to 40M.  160M comes in second for that status.

73,
Rick nk7i


On 11/21/2023 2:55 PM, Andy Durbin wrote:
> "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
>
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