[time-nuts] HP 5370B - result

[Charles P. Steinmetz]

After cooling and restarting the 5370B and observing its behavior, we 
judged that it was more likely it had an unheated 10811 than an 
oscillator of lower stability, so we popped the lid (the possibility 
that it didn't have a 10811/10544 was the reason for leaving it 
intact so it could be returned).  Sure enough, we found a cold 10811 
and an open thermal fuse.  After replacing the thermal fuse with a 
jumper, all appears normal.  (As others have noted, it appears to me 
that if the heater control failed the crystal and heater would suffer 
major trauma before the thermal fuse opened, so we deemed it superfluous.)

Thank you all for your comments and suggestions!

Charles