Re: [time-nuts] backfill (was: Poor man's oven)
The difficulty with hydrogen is to keep it where you want it. It does not take very much for it to leak out (or in, as the case may be) On Jun 8, 2017 4:58 PM, "Alan Melia" 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" > 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 wrote: >>> >>> On Thu, 8 Jun 2017 06:55:07 -0400 >>> Bob kb8tq 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/m >>> ailman/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/m >> ailman/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/m > ailman/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.
Re: [time-nuts] backfill (was: Poor man's oven)
Wouldn't the low density of helium reduce some mechanical friction? I realize the motions are small but they are motions. The "Cousteau effect"? :) ___ 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.
Re: [time-nuts] backfill (was: Poor man's oven)
Hi You really want to use Helium. Hydrogen is a bit reactive. Bob > On Jun 8, 2017, at 5:49 PM, Alan Melia 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" > To: "Discussion of precise time and frequency measurement" > > 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 wrote: >>> >>> On Thu, 8 Jun 2017 06:55:07 -0400 >>> Bob kb8tq 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.
Re: [time-nuts] backfill (was: Poor man's oven)
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" To: "Discussion of precise time and frequency measurement" 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 wrote: On Thu, 8 Jun 2017 06:55:07 -0400 Bob kb8tq 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.
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 wrote: > > On Thu, 8 Jun 2017 06:55:07 -0400 > Bob kb8tq 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] backfill (was: Poor man's oven)
On Thu, 8 Jun 2017 06:55:07 -0400 Bob kb8tq 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.
