asurement
>Sent: Wednesday, December 12, 2012 5:20 AM
>Subject: Re: [time-nuts] Stable Watch Clocks
>
>Hi Simon,
>
>Thanks for the URL. That's one of those tiny 6x2 mm crystals, 20 ppm crystals
>(ouch). The tempco (-0.034 ± 0.006 ppm/ T²) is excellent, though. Now, you can
M. Simon
To: Tom Van Baak ; Discussion of precise time and frequency measurement
Sent: Tuesday, December 11, 2012 9:01 PM
Subject: Re: [time-nuts] Stable Watch Clocks
http://www.abracon.com/Resonators/AB26T.pdf
This quotes .038 ppm/C^2 delta T from the turn o
e art of making what you want from what you can get at a
profit.
>
> From: Tom Van Baak
>To: Discussion of precise time and frequency measurement
>Sent: Wednesday, December 12, 2012 3:55 AM
>Subject: Re: [time-nuts] Stable Watch Clocks
>
&g
> Typical 32KHz clock crystals are very stable in frequency if you can keep
> them
> close to the turnover temp. If you can hold 1 degC it is .04 ppm.
That's far better than I thought. Do you have a reference for this spec?
I agree you might be able to make one accurate to 0.04 ppm, however br
Typical 32KHz clock crystals are very stable in frequency if you can keep them
close to the turnover temp. If you can hold 1 degC it is .04 ppm.
That is 40ppb - very good. If you can hold .1 deg C it is .0004 ppm.
That is .4 ppb. Very expensive. (it goes as the square of the
difference in t
