You also run in to mechanical vibration issues from the cooling system. At the temperatures involved you are looking at something like a Stirling cycle cooler.
Here is a good article; https://arxiv.org/pdf/1309.5445.pdf Maintaining a very stable temperature probably has a much greater impact. Tisha Hayes, AA4HA *Ms. Tisha Hayes* On Mon, Apr 2, 2018 at 2:58 PM, Poul-Henning Kamp <p...@phk.freebsd.dk> wrote: > -------- > In message <299B45118C9248498D7B4F3AFE72231E@pc52>, "Tom Van Baak" writes: > > >Has anyone tried running a quartz oscillator at liquid nitrogen > >temperatures: -196 C (-321F, 77K)? It's probably impractical > >commercially, but maybe something of value to a time nut. > > Whispering gallery sapphire resonators at cryogenic temperatures > is a thing for phase-noise, but those are dielectric (microwave) > resonators, not piezoelectric resonators. > > > Would that dramatically lower temperature improve phase noise & > > short-term performance? > > Yes it will reduce your thermal noise as a source of PN, and > dramatically so. > > But I doubt short and long term performance will improve. > > Even if you can find a zero-turnover cut at a convenient temperature, > I don't think anybody know how to produce mK temperature *stability* > at cryogenic temperatures ? > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.