Though I will never see a OSA 3000, It certainly sounds like a hack could be done to obtain a Cs off reference. But then when you don't actually have one you can make comments like that. Sounds nice. Regards Paul WB8TSL
On Sun, May 28, 2017 at 8:20 AM, Magnus Danielson < mag...@rubidium.dyndns.org> wrote: > Hi, > > On 05/28/2017 11:52 AM, "Björn Gabrielsson" wrote: > >> So while I'm eager to see Donald's results, I question their merit. The >>> >> 5061 standards already have a very convenient Cs-Off switch right on the >> front panel. It is there so you get the pure 10811 performance when you >> need it. Use it. In fact there's lots of people run their precious 5061 >> in >> >>> Cs-Off mode 23.9 hours a day and just turn on the Cs once a day, or once >>> >> a >> >>> week, to re-cal the oscillator. It's not there just to conserve cesium; >>> >> you also get full 10811 short-term performance. Note also some 5061 have >> a >> >>> short/long time-constant switch which also helps you tailor the ADEV you >>> >> want out of the instrument. >> >>> /tvb >>> >> >> Very nice design by HP. >> >> For the same era design, the OSA (telecom) module made other choices. When >> turning off CS, they turn off power to the output module and the efc >> tuning circuit. >> >> So even if there is a nice and warm BVA inside - without burning CS - the >> standard output is not working and also its off any manual tuning. >> > > In addition, and I consider this somewhat of a design flaw, the external > voltage reference to the oscillator (pre-BVA or BVA) is also powered of, so > it drift south rather than stay put. Otherwise it would have been easy to > trim the oscillator for zero lock enforcement and then free-wheel on the > OCXO when Cs is powered down. > > The OSA 3000 and 3100 cesiums are nice analog cesiums, but lacking the > refinement of digitally controlled that came later. > > Cheers, > Magnus > > _______________________________________________ > 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.