[time-nuts] HP 10811A failure

GandalfG8 at aol.com GandalfG8 at aol.com
Sat Oct 13 20:31:24 UTC 2012


Perhaps a silly question, but as I get the impression that both seem  to 
have failed simultaneously with the same fault I'm just wondering  if you're 
sure it isn't what you're checking them with that's  developed a problem?
 
Regards
 
Nigel
GM8PZR
 
 
In a message dated 13/10/2012 13:52:46 GMT Daylight Time, rfnuts at arcor.de  
writes:

Hi  All,

both of my double oven 10811A's have been running flawlessly until  now 
when I noticed that the output power has dropped by about 3 dB  (measures 
only 4...4.5 dBm at 50 Ohm load), and the noise floor has gone  up by 
about 20 dB, while the frequency is still spot on.

I used  them for various mesurements, so I can unfortunately not remember 
what  might have caused the failure. Only the 12V linear lab power supply 
that  fed the heaters had developed a completely dead filter cap, so the 
feeding  voltage was a 100 Hz sawtooth rather than DC. The heaters appear 
to be  still working though. I'm only using the internal heater. They 
draw some  700 mA at power up and drop to around 150 mA  each when warm. 
So the  oscillators are unlikely to be cooked inside. Something must have 
happened  to the 10 MHz output, possibly an ESD issue?

Before I start taking them  apart, can anyone tell what has happened or 
what to look for  first?

Regards,
Adrian



_______________________________________________
time-nuts  mailing list -- time-nuts at febo.com
To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions there.




More information about the Time-nuts_lists.febo.com mailing list