[time-nuts] Re: Is SC the most stable cut for lowest phase noise?

[Dr. David Kirkby]

On Fri, 10 Jun 2022 at 17:39, Lux, Jim via time-nuts <
time-nuts at lists.febo.com> wrote:

>
> On the subject of rapid warm up. I suppose if you had a need, one could
> dump as much power as you need into the heater. Turn on oscillator,
> lights in room dim for a few moments.
>

Is that not likely to damage a crystal? Different parts of the crystal and
likely to be at significantly different temperatures at the same time,
putting a lot of stress on the crystal due to a thermal gradient. It's
probably a bit academic, as nobody is going to make an oven that heats up
in fractions of a second, but if one did, I suspect it might not do the
crystal a lot of good. This is only an educated guess - I don't have
anything to back it up.

At the other extreme,  would there be any advantage in actually heating the
crystal very slowly, over the course of an hour/day/week, so the
temperature gradient across the crystal is very small? Of course, if an
oven took ages to reach the correct temperature, it would be inconvenient
for most applications, but for some applications, the advantages might
outweigh the disadvantages. Of course, if one does this, I suspect one
would have to cool the crystal slowly too to prevent a significant thermal
gradient across the crystal.

I know it's a bit different, but I have a 600 mm f4 Nikon camera lens. I
was told that Nikon cools the front element over a period of 6 months to
reduce stresses in the glass.

Dave