[Elecraft] K1 Nr 1815 frequency drifting

[Yves Dussault]

I have built K1 Nr 1815. Everything works fine. Including the Noise blanker 
and ATU.
But I find that the frequency drifts a lot.
Starting with a cold K1, at 7040.0, after 12 minutes it drifted to 7043.6, 
after 32 minutes, it drifted to 7045.1. It stabilised at
7045.2 Khz.
Is this normal?...The specs say that drift is less than 200 Hz after a 5 
minute warm-up?
What may cause this bad drift?


Yves Dussault
Laval, QC