Murray, Thank you. >> When an OCXO is unpowered for some time, it undergoes a further ageing process when it starts up next. This is specified in some data sheets, and can typically require an hour of burn-in for each day left unpowered before specifications are met.
This is one thing I was curious about. I am asking these questions because I am working with a Rakon/C-MaC double oven OCXO. As I make changes to the power supply, cabinet, EFC power supply, surrounding this OCXO, I wondered how long to let the unit run before I run a standard test on it using TimeLab. Maybe 2 days would be a good compromise? Paul A. Cianciolo W1VLF http://www.rescueelectronics.com/ "Time is relative" Abert Einstien circa 1950 "Relatives use up all my time" Lisa Cianciolo circa 1983 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Murray Greenman Sent: Wednesday, September 14, 2011 3:29 PM To: [email protected] Subject: [time-nuts] OCXO settling There are of course many levels of performance in OCXOs, but in general the ageing slows down with time, and veteran OCXOs can be very good. I recently tested the OCXO in an old HP5245L counter (circa 1970), last calibrated in 1985, and it was still within 100ppb of 10MHz after 24 hours warmup! One point other correspondents didn't answer is the isue of retrace. When an OCXO is unpowered for some time, it undergoes a further ageing process when it starts up next. This is specified in some data sheets, and can typically require an hour of burn-in for each day left unpowered before specifications are met. To answer the question about whether it is best to leave an OCXO turned off when not in use (so it doesn't 'wear out'), I'd suggest that if you don't plan to use it again for a month, turn it off - otherwise leave it running all the time. It should get better with time. 73, Murray ZL1BPU _______________________________________________ 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.
