[time-nuts] 10811-60105 and -60111

Rick Karlquist richard at karlquist.com
Tue Aug 17 13:30:59 EDT 2004

 Talking of OCXOs, supposing I want to build an outer oven around a 10811,
> which could be the right temperature ? Anybody knows the outer oven
> temperature
> of the double ovenized 10811 used in the Z3801A ?   Thanks.
> 73  Alberto  I2PHD

[Note:  I was an R&D engineer at the HP Santa Clara Division
during the development of the Z3801A]

Ovenizing the 10811 is problematical.  The circuitry of the 10811,
even with the oven heaters near zero, generates a fair amount of
heat, and thus you cannot highly insulate it, or the 10811 will
heat itself up to beyond its 70 degree rating.  Then there is
the problem of getting the cables out without heat leaks.  And the
10811 remains sensitive to humidity in any case, unless you want
to hermetically seal it.  All of these things were attempted at
HP as stopgaps while waiting for the real solution, the E1983A oscillator.
I wouldn't advise trying to homebrew a double oven 10811.  It
was a kluge even when HP did it.  If you insist on trying to
do this, I suggest you read my paper on oven design for some
pointers (http://www.karlquist.com/oven.pdf).

Rick Karlquist

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