[time-nuts] 5370A

Chuck Harris cfharris at erols.com
Sat Oct 10 16:01:32 UTC 2009

One thing to note, the 5370A has a slim line relay (K1) in the power supply
that switches all of the voltages on... it is there for the crystal oscillator.

I had one that didn't produce enough contract pressure to reliably switch on all
of the voltages, and would quit if you bumped it lightly.  I had to readjust
the contact spring pressures, and it became reliable.

-Chuck Harris

Greg Burnett wrote:
> Roy,
> The HP 5370A rear mounted heat-sink typically heats up to around 61 degrees 
> C. This is very hot to the touch, so I suspect your unit's temperature is 
> normal (unless it's running way hotter than 61 degrees C).
> The buzzing transformer might just be due to loose, vibrating laminations. 
> You might try tightening the transformer's bolts to see if that reduces the 
> buzz?
> Best,
> Greg
> P.S. I agree that the rear mounted heat sinks of most other HP equipment run 
> significantly cooler. The models that run so hot to the touch are the 
> 5370A/B, 5359A, and many of the legacy HP pulse generators (from Boblingen 
> Division).

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