[time-nuts] Frequency standard

Dan Rae danrae at verizon.net
Sat Jan 26 22:38:36 UTC 2019


On 1/26/2019 1:31 PM, Bob Albert via time-nuts wrote:
>>     I am, as I have said, money limited to the point where most solutions won't work for me.
>> My counter is an HP 5328A I belive.  Not the top of the line but with care it can do a decent job.  It's oscillator is the standard oven job.  When I got it, it was almost spot on but it's been a while and I'd like to reset or at least recheck it.

Bob, If you are willing to spend $70 you can get a fairly decent GPSDO 
receiver from eBay. For that money I recently bought a Samsung UCCM 
gpsdo.  Add to that the price of an antenna, cable(s), case and power 
supply and you'll be good to go with a 10 MHz signal that will be 
perfect for your needs.  I recommend the UCCM boxes for you because they 
are pretty well automated; when first connected they do a self survey, 
store the position they find and then start to output very accurate 10 
MHz and 1 pps signals, all with no outside intervention.  Not so popular 
perhaps with time nuts who would like to be able to tune their devices 
for ultimate performance but the simplicity of these can't be beat. Now 
you can calibrate your OCXO in place, or better still just feed the 
counter from your GPSDO.

If you can't get an antenna up with a good view of the sky to the south 
then Rubidium units are available which once set will do you for 
years.   I'm guessing, maybe double the figure I quoted above, then add 
power supply and case.

Calibrating your OCXO won't be easy if you do it elsewhere. First most 
OCXOs will take about two days to settle, then the frequency will depend 
to some extent on the unit's orientation. Finally if you turn it off and 
then on again, it may well come back to a slightly different frequency, 
that's called retrace. And all OCXOs will drift over time, some worse 
than others.

Dan

ac6ao







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