Hi Vacuum stuff sells by the pound (more or less). The kind you need in this case isn't the cheap stuff. Pounds go up by the cube of the size. In this case, I believe you want the fountain portion of the gizmo to be fairly small.
Bob -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Tuesday, December 04, 2012 9:49 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] PTTI 2012, part 2 Basements the key. So for me bigger is better. Heck if its a rack thats ok. It gets interesting in what types of components you can use if you are willing to go larger. Great point on the laser and optics. Funny thing is for small change you can actually get used optics bench components at least at the last MIT flea I ran across the items. They were snapped up by the way. >From what I have seen of time-nuttery and Hydrogen masers I am actually not all that sure its beyond this group. Regards Paul On Tue, Dec 4, 2012 at 9:34 AM, Bob Camp <li...@rtty.us> wrote: > Hi > > Indeed, you likely won't get USNO grade with a shoe box sized part. You can > get one to work and do quite good ADEV. No, I haven't done it, I'm just > going on what I've been told. The main point being that for a basement > project - smaller is probably lower cost. > > Bob > > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Poul-Henning Kamp > Sent: Tuesday, December 04, 2012 9:19 AM > To: Discussion of precise time and frequency measurement; Bill Dailey > Subject: Re: [time-nuts] PTTI 2012, part 2 > > -------- > In message > <CAMPhiorJihW9z6-q0+Qfd+GPLjs6e8_ovWrDxQoxV=92hgj...@mail.gmail.com> > , Bill Dailey writes: > > >If you look at the papers on portable rubidium fountains > >they are significantly bigger than a shoebox (65 cm). > > Diameter is controlled by dispersion of the launched atoms (=recovery rate) > and the layers of shielding. > > 65cm looked like close to a minimum for USNO grade, amateurs could probably > make do with less shielding. > > -- > 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. > _______________________________________________ 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.
