Hi At least at the 1 second point, I believe that the main issue with getting an order of magnitude better than the 3x10^-13 point is the lack of funding for a decent crystal package for 25+ mm diameter blanks.
I doubt I'm going to solve that one in the basement .... Bob On Dec 23, 2009, at 3:17 PM, Lux, Jim (337C) wrote: > >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of Bob Camp >> Sent: Wednesday, December 23, 2009 9:52 AM >> To: 'Discussion of precise time and frequency measurement' >> Subject: Re: [time-nuts] Cheap Rubidium >> >> Hi >> >> If you can achieve <= 1x10^-13 at 10,000 to 100,000 seconds, that's quite a >> bit better than any OCXO has a right to be doing. Yes I know that there is >> one in the entire universe that gets close. >> >> Even if you just do < 1x10^-12 at 1,000 seconds, that's better than a whole >> lot of OCXO's will do at that tau. >> >> The place where the OCXO does come in is < 100 seconds. Between 1 and 100 >> seconds you can get a number of OCXO's that will run <2x10^-12 over the >> entire range. You can fine a lot more that will do < 1x10-12 over that range >> than you can find that will do < 1x10^-12 at 1,000 seconds. The rubidium is >> struggling to get to 1x10^-11 at 1 second and may or may not get to 1x10^-12 >> at 100 seconds. >> > > > Typical (Cassini, MGS, etc., data from Sami Asmar) UltraStableOscillator > (USO) specs as used in spaceflight do about 1E-13 at tau =10 to 1000 seconds, > 3E-13 at 1 second. Today, you can probably do maybe an order of magnitude > better. These are state of the art oscillators in a vacuum envelope with > double ovens, etc. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
