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

[Richard (Rick) Karlquist]

We did a lot of characterization of crystal temp
vs freq in the E1938 development and never observed
any "aging" of these curves.  Even on "green" crystals
with zero run time.

Rick Karlquist N6RK

Jeff Mock wrote:
> Thanks for the description, it is very interesting.  I have a follow up 
> question if you don't mind.
> 
> How does crystal aging look on a graph of temp versus frequency.  This 
> graph has some temperature point where the slope of frequency variation 
> goes to zero and the crystal is quite stable around this temperature.
> 
> What does this graph look like as a crystal ages?  Does the optimal 
> operating temperature change over time, that is, does the graph tend to 
> move left and right, or does aging tend to move the graph vertically 
> (the optimal freq stays the same, but the optimal operating temperature 
> changes as a result of aging).
> 
> I hope this makes sense...
> jeff
>