[time-nuts] Thunderbolt oven / non-stable operating temperature

bg at lysator.liu.se bg at lysator.liu.se
Wed Dec 12 11:43:05 UTC 2012

> tvb posted>
>>Were you able to test how quickly, or how well, the filter learned the
>> tempco of the OCXO?
>     Only at a couple of very general data points.
> Using a very Bad unit, the Kalman filter had an effect, although not very
> good in under 1/2 day.
> After a week or so on a good unit, it helped maybe 3 to1 with ageing and
> Temperature TC.

Not contributing vs your information in detail or quality. But here is
some terse information from Trimble regarding holdover for the Tbolt.

   "This voltage steers the oscillator correcting for temperature and
aging effects by using a Kalman Filter.  The Kalman filter works by
observing the behavior of an oscillator over temperature and time while
GPS is locked.  This is called the training period."


kind regards,


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