[time-nuts] Oscilloquartz 8601 Rebuild Question

ed palmer ed_palmer at sasktel.net
Mon Aug 1 15:24:47 UTC 2011

   John & Don,
   Thanks for your thoughts and ideas.  Limited availability of different
   sizes and shapes of vacuum bottle is a problem, but I'll be keeping
   your ideas in mind when I make my selection.
   On 7/30/2011 6:29 PM, J. Forster wrote:


That will give you a static match, not necessarily a dynamic match.
Consider if you filled the Dewar with mercury.

Certainly a thermos of mercury would have much different thermal
behaviour than an oscillator, but I don't have a thermos of mercury.  I
think what you're getting at is whether my replacement thermal system
has similar dynamic thermal characteristics to the original.

Yes. You should, IMO, try to match the heat leak and the thermal inertia
to keep the loop dynamics the same.

Unfortunately, there's no way for me to test that since the original is
smashed.  Static comparison is all I can do.

You can try to keep the Dewar internals as near as possible to the
original. That and the leakage should roughly do it.




Of course, if you go too far in reducing the current, the oven could
overheat.  The oscillator includes a precision thermistor to monitor
temperature of the oven to prevent this.

Any comments?


Good luck.


Thanks.  This is turning into an interesting project.


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