[Elecraft] Does the K3 drift??

[ANDY NEHAN]

I noticed this question somewhere and I decided to conduct a small experiment. Now I have K3 serial 6990 with the KTCXO3-1  TCXO                              
I have a 10MHz signal source locked to Droitwich in the UK and stable to about 1Hz in 100MHz. So I set up the K3 to hear the 10MHz signal and monitored the sidetone on my frequency counter (which I had let warm up for well over an hour). It varied between 598 and 605Hz - a change of 7Hz over a 1hour period when the room was warming up and the K3 had been turned on from cold overnight.
BTW the K3 display remained unchanged throughout this time.
I have no reason to assume my K3 drifts as the drift I observed was well within the experimental error of my measuring process. I don't have the quality of instrumentation to achieve a more accurate result but from what I saw there is no problem. Clearly YMMV.
Andy G4HUE