Sounds like another dead cap. Thomas Knox
> Date: Sat, 13 Oct 2012 14:51:54 +0200 > From: rfn...@arcor.de > To: time-nuts@febo.com > Subject: [time-nuts] HP 10811A failure > > 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@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.