Hi There is a lot of data that says crystals "relax" while off power. The older they are (the older the process) the more likely they are to do so. The net effect is that they will move much faster on a per day basis than you would expect them to. They will eventually calm down, but it can take months. Things like mounting stress (TCE miss match), and thermally introduced changes in junk equilibrium are the two most commonly claimed sources.
One example is the GR standard I have in the basement. It's now down to a sub 1.0x10^-11 per day sort of aging rate. When I fired it up, it was moving more than 1.0x10^-8 per day. As with any rule like this, there will indeed be parts that break the rule. Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of J. Forster Sent: Friday, January 14, 2011 12:45 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] CS reservoir depletion Bob, is there any indication in you have to "run it for a while" depends on how long it has been off? Does a crystal oscillator that has been off for 50 years, take longer than one that has been off for a week? I ask because the 1818.18 Hz crystal in a LORAN-A Test Set I picked up is currently running at about 1818.48 Hz. It's been off since about 1945. Best, -John =============== [snip] That assumes it was on power for a good part of > it's > life. If it's been on the shelf for 20 years, you may need to run it for a > while ... > > Bob > _______________________________________________ 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.
