Richard (Rick) Karlquist
richard at karlquist.com
Thu Jun 8 19:21:26 EDT 2017
Bob is exactly right. Read up on "mean free path" physics.
Just a little air will take care of conduction.
Full atmospheric pressure would drop the Q something like
a factor of 2.
In any event, conduction through the crystal mounts is
plenty adequate for the tiny thermal mass of the crystal
itself. The mounts are embedded in the ceramic header,
which is fairly conductive.
On 6/8/2017 1:19 PM, Bob kb8tq wrote:
> If you look at the thermal conductivity vs very low pressures, the conductivity
> comes up pretty quickly from a hard vacuum. There is essentially no impact
> on Q.
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