[time-nuts] Improving the stability of crystal oscillators

[Brooke Clarke]

Hi Bruce:

I've also looked into drilling a hole (garden hose, 90 deg fitting & pipe with 
end smashed flat to make a nozzle will easily drill as deep as the pipe is 
long).  Then using a short length of capped copper pipe at the bottom and the 
rest PVC.

Like I think here in California wine country 4 feet would be plenty deep.  But 
this method only works at your home location.  Not too good for a clock that 
will be sent to someone else.

I think the long time constant method can be done in a few cubic inches.

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam


Bruce Griffiths wrote:
> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+brooke=pacific.net at febo.com RETRY
> 
> Brooke Clarke wrote:
> 
>>Hi:
>>
>>Something I've been thinking about is attaching a large thermal mass of 
>>aluminum to the crystal and it's oscillator then surrounding that with 
>>insulation.  Then surround that with a thin copper layer.  Temperature sensors 
>>on the copper and aluminum.  If the thermal time constant could be made very 
>>close to 24 hours, or integer multiples of that, it might be possible to 
>>predict the inner temperature allowing compensation.
>>
>>Has this already been done?
>>
>>  
> 
> Brooke
> 
> Why stop there?
> Try burying the oscillator under 6ft or so of soil.
> The daily temperature fluctuations at this depth are very small.
> 
> Bruce
> 
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