Bob wrote:
As best anybody can tell, the improved phase noise and ADEV 10811's came out of a screening / select process. There is a finite chance that a "normal part number" 10811 could be as good as or better than a part from one of the "better part number" versions.
That is particularly true now that they all have decades of aging. The specs were written for new units with fresh crystals, which are nearly always less stable than well-seasoned crystals (e.g., you will often find annual drift specs given separately for "first year" and "subsequent years").
At this point, I think it is essentially random which individual 10811s are most stable (and, of course, it also depends on what you mean by "more stable" -- is the oscillator that drops to 1e-12 by 1 second and stays below 5e-12 through 1000 seconds more or less stable than the one that is 2e-11 at 1 second, drops to 1e-13 from 20 to 100 seconds, and is back up to 2e-11 at 1000 seconds?). I certainly haven't noticed any pattern with the 10811s that have been through my hands.
I know -- everybody, label all of your 10811s with your name and address, box them up, and send them to Tom with a return shipping label and sufficient postage. He can run each one for PN and xDEV (after burning each one in for a week, of course), publish all of the data, and return them. ;-) We're bound to have at least a few thousand between us. Don't forget the ones in your counters and other equipment!
Best regards, Charles _______________________________________________ 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.
