[Elecraft] K2 intermittent problem

[Igor Sokolov]

My K2 developed a problem. In CW mode TX frequency is off the RX frequency
by about 1 kHz. The problem is intermittent. Sometimes it manifests itself,
sometimes it does not.
Can anybody give me a hint where to look? I was about to see if changing CW
pitch changes the offset but so far cannot make the problem to appear again. 
So far there were no evidence that the problem is temperature dependant.

73, Igor UA9CDC