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). ----- Original Message ----- From: "Roy Phillips" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Sent: Saturday, October 10, 2009 4:08 AM Subject: Re: [time-nuts] 5370A Hi Joe I have a similar problem so I would be pleased to hear from you with any useful information. The basic problem with mine is that the power supply is suspect - it works, but there is excessive heat, much greater than any other HP instrument that I have, from the rear mounted heat-sink, this is too hot to hold your hand on ! There is also a very obvious buzz from the power transformer, even when it is on "stand-by" - so I guess at worst it could be shorted turns in the power transformer, or probably better, a faulty bridge rectifier,or one or more of the large reservoir caps - this an early model (1984), so perhaps it is to be suspected. I also think the performance is not to specification, but I will check-out the perceived problem with PSU before I investigate this matter. I am just about to start the investigation of the prime problem. Roy _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
