[Elecraft] KPA 100 Instability

[Michael Clutton]

Hi All,
I have been using my K2 s/n 01319 with most of the various mods and
firmware upgrades available for about 3 years with no problems at all.
I recently went QRO with the KPA 100, this works great on 160, 80,  40
and 30 mtrs. Unfortunately on any band above this it becomes very
unstable within a few seconds of speaking into the microphone the
power meter just goes full scale.
I disconnected the KAT100 and fed the KPA 100 directly into my Yaesu
dummy load come power meter and exactly the same happens, full scale
deflection 150 w plus. I changed the microphone from the Kenwood MC80
desk microphone for a bog standard Kenwood fist mike, but my problem
is still there.
The KPA 100 is built into the K2 case, any suggestions would be very
much appreciated.

                       73 de Mike G4VQH