[Elecraft] K3 Intermittently loses gain

[Ron W3ZV]

Started to play in the CQWWSSB. K3 started to exhibit intermittent loss 
of gain after a transmission. Sometimes, stomping on the foot switch 
brings it back up. Sometimes it takes a short transmission.  No real 
pattern to when it occurs. Receiver isn't totally deaf. Just way down. 
Any ideas as to where the problem might be? I'm guessing its time for 
the radio to take a trip home to the left coast.

Ron W3ZV