Hi The “normal” approach is to stabilize the inner wall and cross section (= open tube) of the dewar. Often this is done with a metal “plug”. It may or may not extend to the bottom of the dewar. A lot depends on fiddly little details about how much heat you are generating in the circuitry inside the “controlled area”.
Bob > On Aug 2, 2019, at 10:51 AM, Dana Whitlow <[email protected]> wrote: > > Question: > > Do you stabilize the oscillator inside the dewar, or do you stabilize the > temperature of > the dewar's outside environment? > > This may boil down to a slightly different expression: Where do you *sense* > the temperature for > the stabilization loop? On the crystal itself, or on the outside wall of > the dewar? > > Thanks, > > Dana > > > On Fri, Aug 2, 2019 at 4:00 AM Bill Slade <[email protected]> wrote: > >> Hello! >> I have done this and can attest that it works well. I did not use a TCXO, >> though. I used a 48 MHz, third-overtone AT-cut crystal in a Colpitts >> oscillator configuration. The vacuum flask was ovenized to maintain >> temperature near the stationary point of the temp characteristic (near 50 >> deg C). The oscillator could be phase locked to an external atomic >> reference (in our case, a rubidium) or 10 MHz from a GPS receiver. >> >> The inspiration was a couple of excellent NASA reports from some years >> ago, which I have attached (as links because files are large) for >> convenience. >> Cheers, >> Bill >> Nasa Precision Quartz 1< >> https://onedrive.live.com/embed?cid=3CBCA1CF8AB21FE1&resid=3CBCA1CF8AB21FE1%213504&authkey=AA4EqyT05-Iz2nU&em=2 >>> >> Nasa Precision Quartz 2< >> https://onedrive.live.com/embed?cid=3CBCA1CF8AB21FE1&resid=3CBCA1CF8AB21FE1%213505&authkey=AEG_NqxtMFVIE_o&em=2 >>> >> >> On 02/08/19 01:35, Perry Sandeen via time-nuts wrote: >> >> Yo Bubba Dudes!, >> If one has the space, a simple cure might be to get one of the wide mouth >> thermos containers that they sell in large variety stores such as Wal-Mart >> for being able to eat something like stew or some semi-solid hot food out >> of the container itself. >> Regards, >> Perrier >> _______________________________________________ >> time-nuts mailing list -- [email protected]<mailto: >> [email protected]> >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
