[time-nuts] Super stable BVA Quartz resonators... BVA??

[Bernd T-Online]

Javier wrote:
> Anyway, a 10544 oscillator has a cold 
> offset that can easily be of 1000Hz, so if at 80 deg. C the offset is 
> zero, and at 25 deg. C the offset is 1000Hz, you easily have a rough 
> 15Hz/deg C average tempco in that range - and the aging drift for this 
> oscillator is quite less than that.

The 10544A incorporates an AT cut crystal. The tempco is far away from 
being linear. From room temp to the oven temperature it follows a 3rd 
order parabola, which has its minimum at the oven temperature. This 
"trun-over tempearture" varies from unit to unit, which means that the 
slope of f(T) also changes form unit to unit.
Not the best approach for measuring temperatures ;-)
At the other hand, the current consumption of the 10544A decreases 
fairly linear with temperature, so this is a better (but rather slow) 
temperature sensor, which would even work without the quartz...

Regards

Bernd
DK1AG