I am sorry I assumed you had resolved your PS issues, I should have been clearer, I meant bad cap in the oscillator. I would temporarily solder a number of leads internally and check the different voltages for noise. Good luck on the repair.
Thomas Knox > Date: Sat, 13 Oct 2012 17:30:27 +0200 > From: [email protected] > To: [email protected] > Subject: Re: [time-nuts] HP 10811A failure > > At least not a power supply cap. No change on a different PS. Do you > mean the oscillator output coupling cap? > > 12V for the oven because inside the outer oven lives a 10811-60158 ( see > http://www.realhamradio.com/GPS-oven-journey.htm ) that, as by the specs > sheet, is specified 12 to 30 V DC, 11 W max. at turn on (mine draws some > 9 W), and Steady state power drops to approximately 2 W at 25°C in still > air at 20 V (mine draws some 1.9 W at 12 V without powering the outer oven). > > Adrian > > > Azelio Boriani schrieb: > > 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. > > > > > > _______________________________________________ > 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.
