2009/8/7 Chuck Harris <[email protected]>: > If I recall correctly, the HP quartz oscillator manuals say that you must > allow > at least 72 hours of burn in after shipment from the factory, and 72 hours > between > frequency adjustments. > > Double oven quartz oscillators are dodgy things. The Sulzer 2.5C and HP > 107's that live > in my shop have an interesting characteristic: They age upward in > frequency, and I > make the appropriate adjustments every few days. But if I break power for > even an instant, > the crystals pop down in frequency to about where they were back when they > were last > started... And it takes them months to get back to where they were before > the power quit.
I have seen this too and wondered what is going on here. Maybe some day I will collect data from startup and then cycle the power to see if the next set of data corresponds in some fashion to the original aging. Cheers, Steve > > -Chuck Harris > > Mark Sims wrote: >> >> The first question to ask is how long had the unit been inactive and how >> long has it been powered up? I have noticed >> on several 5370 counters that the oscillators took several (4-6 weeks) to >> stabilize after I received the units. I am >> pretty sure that the units had been inactive for quite a while and were >> not recently removed from operation. >> >> I had them connected to a Tbolt or cesium oscillator. I would set them >> each morning to a few counts above 10 MHz. >> By the next morning the reading was below 10 MHz. It took between 4 and >> six weeks for the units to stop drifting. >> Interestingly, the 10544 oscillators drift much less than the 10811's >> and all the oscillators drifted in the same >> direction. >> >> Before doing any serious study of your 106B, I would plug it in, leave >> it on, and let it cook for a couple of >> months. >> >> ---------------------------------------- >> >> >> _________________________________________________________________ Windows >> Live™: Keep your life in sync. >> http://windowslive.com/explore?ocid=PID23384::T:WLMTAGL:ON:WL:en-US:NF_BR_sync:082009 >> _______________________________________________ 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. > -- Steve Rooke - ZL3TUV & G8KVD A man with one clock knows what time it is; A man with two clocks is never quite sure. _______________________________________________ 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.
