[R-390] Question about R-390 Calibration Osc

[Grant Youngman]

Simple question.  Is it normal for the multivibrator in the cal oscillator
to require the radio to warm up well before synchronizing with the 1 Mhz
oscillator?

Calibrator operation has been iffy at best, so since I had the radio out of
the case to replace a bad 6082, I decided to tackle the calibration
oscillator issue.  It's basically hard to keep the 100Kc multi synced to the
master oscillator.  If I set the sync adjustment when the radio is cold to
sort of warm, it loses sync as it gets hot.  If I wait until it's hot to
adjust it, it won't sync until the cold radio has been on for 15-20 minutes.
And then it will occasionally lose sync for a while, then resync -- always
out of sync seemingly when I want to change bands and reset the dial :-)

The 1 Mhz oscillator appears to be ok.  New tubes (which seemed to help
somewhat at first, but ultimately not so much)

Is this normal?  Or is it reasonable that something in there that has
possibly degenerated and become temperature sensitive (such as C-909 or
C908)?

Any suggestions on what to poke at first? -- it's a tight spot to work in
there.

Grant/NQ5T