And, why 12V for the oven? The 10811A manual states from 20V to 30V for the oven. 12V for the oscillator itself.
On Sat, Oct 13, 2012 at 4:34 PM, Tom Knox <[email protected]> wrote: > > Sounds like another dead cap. > > Thomas Knox > > > > > Date: Sat, 13 Oct 2012 14:51:54 +0200 > > From: [email protected] > > To: [email protected] > > 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 -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > 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. > _______________________________________________ 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.
