Hi You really want to use Helium. Hydrogen is a bit reactive.
Bob > On Jun 8, 2017, at 5:49 PM, Alan Melia <alan.me...@btinternet.com> wrote: > > Hi Bob, it also depends on what you allow to leak into the vacuum. Hydrogen > is a pretty effective remover of heat :-)) > Alan > G3NYK > > ----- Original Message ----- From: "Bob kb8tq" <kb...@n1k.org> > To: "Discussion of precise time and frequency measurement" > <time-nuts@febo.com> > Sent: Thursday, June 08, 2017 9:19 PM > Subject: Re: [time-nuts] backfill (was: Poor man's oven) > > >> Hi >> >> 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. >> >> Bob >> >>> On Jun 8, 2017, at 4:03 PM, Attila Kinali <att...@kinali.ch> wrote: >>> >>> On Thu, 8 Jun 2017 06:55:07 -0400 >>> Bob kb8tq <kb...@n1k.org> wrote: >>> >>>> The simple answer is that the backfill is done because it does matter in a >>>> lot of >>>> cases. >>> >>> This raises the question, why there is backfill (just for thermal >>> conductivity?) >>> and how much it affects the Q of the crystal. >>> >>> Attila Kinali >>> >>> >>> -- >>> You know, the very powerful and the very stupid have one thing in common. >>> They don't alters their views to fit the facts, they alter the facts to >>> fit the views, which can be uncomfortable if you happen to be one of the >>> facts that needs altering. -- The Doctor >>> _______________________________________________ >>> 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. > > _______________________________________________ > 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.