[time-nuts] OCXO pressure sensitivity before TCXO

[jimlux]

On 8/5/19 2:21 PM, Poul-Henning Kamp wrote:
> --------
> In message <d4c46442-c783-fde9-d8da-2b32cb11f201 at earthlink.net>, jimlux writes:
> 
>> One other thing to know about those USOs - they start about 1000 quartz
>> blanks that are mounted in holders, and wind up with a couple dozen
>> oscillators in dewars, and then run them all for a long time (many
>> months) and watch them.  2 or 3 out of a batch will be the ones selected
>> for use - based on their observed stability -
> 
> Do you know where their trash bin is located, and if it is locked ?  :-)
> 
> I would love to get my hands on a unit from, say, the 10-25 tier of that process.
> 

I think they do get reused - the aging process is just the oscillator 
without all the rest of the electronics.  And there's always a need for 
engineering models and qual units for environmental testing.

I'll bet that's why they developed the USO with a built in DDS - so that 
one that turned out to be 22.12345 MHz can be "reprogrammed" for 
10.000000 MHz