[Elecraft] XG50 - Frequency Instability

[kj7rt at kj7rt.com]

I am trying to use my XG50 to run the Extended Temperature Compensation
Procedure on my KX3. This is the first time I have attempted to use the
XG50 since building it. I have completed the 8 hour burn-in.

When I first connect the XG-50 to my HP frequency counter, I get a
reading of something like 49.379990. Then after running for several
minutes it starts dropping in frequency to something more like
49.32xxxx. It is still wildly fluctuating. If I connect the 10MHz output
of my Trimble Thunderbolt GPSDO to the counter it stays quite stable
just below 10 MHz.

I re-soldered all the XG50 components and tried with both a metered
home-brew power supply and a 12v SLA battery with the same result
although re-soldering made a significant but not permanent improvement.

My lab is in my photographic darkroom which has an ambient temperature
of about 68 degrees F and the AC does blow across the work area.


Thanks,

Gary Marklund
KJ7RT
Sun City, AZ
USA