[time-nuts] What cut do I have?

M. Simon msimon6808 at yahoo.com
Tue Jan 29 03:15:11 EST 2013


Those 32KHz watch crystals are very flat in the vicinity of the turnover. They don't age well. But if all you need is temperature stability and you can correct for aging a nice little electric heat pump (heats and cools) to keep the crystals at around the 25C inflection point might be interesting. The heat pump might not take too much power either. 

The temp error runs .04 (Tturnover - T)^2 ppm. i.e. .1 deg C from turnover gives .0004 ppm freq change. That is .4ppb. if you can hold .03C (not too difficult) you get 10X better - .04 ppb. Aging of course will be a killer with respect to that. 


http://www.iqdfrequencyproducts.com/app-notes/timekeeping/


======

Nice page on cuts:

http://www.4timing.com/techcrystal.htm

Engineering is the art of making what you want from what you can get at a profit.


More information about the time-nuts mailing list