[Elecraft] K2 Frequency Shift On 80 Metres

[Ray Spreadbury]

Hi Elecrafters

I have recently bought a second-hand K2 with the KSB2 SSB module, the KPA100
100 watt amplifier & the KAT100-1 antenna tuner. Everything appears fine
running either QRP or 90+ watts on all bands except 80 metres. I am using an
off centre fed dipole (133') and the KAT100-1 antenna tuner to match.

Running in excess of 10 watts or so on 80 metres however when I switch the
microphone, the tuning apparently shifts to another frequency on the band.
The shift may be a few Hz or even a few 100Hz. The receiver is then on that
new frequency. Reducing power back to a QRP level, the transmitter &
receiver behave normally.

I guess there's something wrong with the 80 metre sections of the KPA100
and/or the KAT100-1.

Any clues of what I should check please?

73

Ray, G3XLG