[time-nuts] Fwd: HP5061B Versus HP5071 Cesium Line Frequencies
paulswedb at gmail.com
Sun May 28 12:06:43 EDT 2017
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.
On Sun, May 28, 2017 at 8:20 AM, Magnus Danielson <
magnus at rubidium.dyndns.org> wrote:
> 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
>>> Cs-Off mode 23.9 hours a day and just turn on the Cs once a day, or once
>>> 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
>>> short/long time-constant switch which also helps you tailor the ADEV you
>> want out of the instrument.
>> 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.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> and follow the instructions there.
More information about the time-nuts