[Elecraft] KX1 oscillation

[Pete Meier]

Just started Alignment P2 after all previous tests and measurements 
shown at proper values.
When I plug in headphones I am hearing a very high pitched constant 
tone. I assume is something gone into oscillation.
It is not the sidetone and everything acts correctly. I can

Any idea what might be causing this tone/oscillation? I can hear the 
sidetone and adjust it but, of course, it sounds distorted mixing with 
this contant tone. This tone increases volume with the audio level as 
controlled by the AF GAIN.

Any advice how to approach this will be appreciated.

Pete WK8S
pmeier@mac.com