[time-nuts] Thermal insulation choice?

[Rick Karlquist]

Bob Camp wrote:
> Hi
>
> A metal shell inside a metal shell pretty well takes care of everything.
> Gradients, transients, drafts, what ever. You don't need super thick
> stuff.
> Bud chassis, Hammond boxes, copper pipe, PC board material, or soldered
> brass flashing all will do the trick.

We also tried mounting the modified 10811 in Hammond metal box.
Initially, we mounted the 10811 to the box using the
two standoffs that come with the 10811.  However, this
degraded the performance somewhat.  We removed these and
had the 10811 supported mechanically only by the edge
connector.  With that change, it was as good as the cardboard
box.  Remember that my modified 10811 is orders of magnitude
more sensitive that an ordinary oscillator, so if I don't see
a change, you definitely won't.

During E1938A development, we compared foam to still air.
We could see no difference.  It's just an implementation choice.

Rick Karlquist
N6RK