Crystal Calibrator Question - HW-101

[Mike Hardie]

The crystal calibrator in my '101 decided not to work until the rig had
warmed up for about an hour.  Applying heat from a hair dryer to the 100 kcs
crystal before the warm-up period resulted in the calibrator working.
Replacing the crystal has cured the problem, I usually let it warm up
anyhow.

Here's the question.  With the old crystal still installed a continuous
faint tinkling noise would start shortly after selecting "cal".  The source
of the noise was hard to pinpoint but I'm fairly certain it came from V17,
the 12AT7 associated with the calibrator.  This happened whether the
calibrator was working normally or not, but it had to be selected "on", and
would stop as soon as the calibrator was selected "off".  Substituting a
different 12AT7 in V17 made no difference.  Any ideas on what was causing
the noise?

Mike VE7MMH

Sponsored by the City of Tempe 

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