Slow by 44 ns in 27 minutes. -2.7 e-11 Regards Paul On Sat, Dec 6, 2014 at 5:24 PM, Magnus Danielson <[email protected] > wrote:
> Yes, but what's the offset? > > Cheers, > Magnus > > > On 12/06/2014 10:12 PM, paul swed wrote: > >> The system does consistently come to lock with a constant offset. So its >> finding something. Just the odd little offset thats bugging me. >> >> On Sat, Dec 6, 2014 at 2:48 PM, Magnus Danielson < >> [email protected] >> >>> wrote: >>> >> >> It's a challenge indeed. IF you are running on fumes, it will be harder >>> for the automatic locking to find first and second modulations, and if it >>> does this, it is much more likely to be the central pedestal as the >>> others >>> will be even further down into the noise. The lack of the fundamental >>> tone >>> will cause that FLL may fail to lock, since the sweep signal can be too >>> strongs, and if it does lock, it will be weak as the loop gain will be >>> off >>> by the lack of signal and then naturally the S/N will be problematic. >>> >>> Not sure that it in itself will be the cause of systematically drifting >>> of >>> the mark, but rather varying a lot around that mark. >>> >>> Cheers, >>> Magnus >>> >>> >>> On 12/06/2014 08:16 PM, paul swed wrote: >>> >>> All good answers with a good tube and enough current to read on the >>>> meter. >>>> But I am working at the very limit of the Cs fumes. There is current, >>>> about >>>> .5 to 1 tick mark on the meter of a 5061 using a 5060 tube. >>>> Thats the challenge on a very eol tube. >>>> Regards >>>> Paul. >>>> >>>> On Sat, Dec 6, 2014 at 1:56 PM, Magnus Danielson < >>>> [email protected] >>>> >>>> wrote: >>>>> >>>>> >>>> Tom, >>>> >>>>> >>>>> On 12/06/2014 06:04 PM, Tom Van Baak wrote: >>>>> >>>>> Paul, >>>>> >>>>>> >>>>>> There are 7 peaks total, about 40 kHz apart (on my 5061A). If you're >>>>>> talking about just the central peak, there are two smaller peaks on >>>>>> either >>>>>> side, about 1 kHz apart. The exact value depends on internal magnetic >>>>>> field, which is specific to each beam tube design. >>>>>> >>>>>> For some measurements of all the peaks, have a look at: >>>>>> http://leapsecond.com/pages/cspeak/ >>>>>> >>>>>> >>>>>> These are the 7 Zeeman pedestals, and on top of them you have the >>>>> Ramsay >>>>> fringes. You can indeed lock onto the wrong Ramsey-fringe, but they too >>>>> have amplitude differences. For a normal tube, they are quite >>>>> significant, >>>>> but if you look at the Ramsay fringes on the NIST-F1, they are much >>>>> denser >>>>> and looses amplitude much slower, so you need to pay more details of >>>>> which >>>>> fringe you use. The density of the Ramsay fringes is due to the >>>>> observation >>>>> time, which has been one of the driving forces to develop hydrogen >>>>> masers >>>>> and cesium fountains, but for a simple cesium tube, it's a few dm of >>>>> distance and the average speed of the cesium steam. >>>>> >>>>> You can play with the C-field in addition to playing with peaks: >>>>> >>>>> http://leapsecond.com/images/cfield.gif (578 x 4610 pixels) >>>>>> >>>>>> >>>>>> Which is a good illustration. It would be good. >>>>> >>>>> For more details search the archives for the word Zeeman. For >>>>> example: >>>>> >>>>> https://www.febo.com/pipermail/time-nuts/2005-April/018171.html >>>>>> >>>>>> A nice description from hp how a cesium beam standard works: >>>>>> http://leapsecond.com/museum/hp5062c/theory.htm >>>>>> >>>>>> >>>>>> Do check the FTS-4065C manual as I just uploaded. Good complementary >>>>> information. >>>>> >>>>> Cheers, >>>>> Magnus >>>>> >>>>> _______________________________________________ >>>>> 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. >>>> >>>> _______________________________________________ >>>> >>> 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. >> >> _______________________________________________ > 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.
