[time-nuts] Re: pulling some crystals

[glen english LIST]

Ed and Ben,  thanks very much for the input.

Yeah I am going to have to look into the aging of the frequency 
sensitive parts in the circuit . I've never had to do this before - when 
I've built an OCXO, there has always been the expectation that someone 
could tweak it once a year per year  if necessary .

Of course, this stuff is not new. Try retweaking your XO out beyond 
Saturn ...... My guess is I'll need to tweak the L in the OT oscillator, 
so I could switch in L in binary bulk steps maybe (rather than the 
traditional tiny ally core slug tuned L I have used) .  Of course there 
will be a limit to how far I can go.

There are certainly some DC bias aging effects on high K dielectric 
MLCCs. According to  :

https://www.knowlescapacitors.com/getmedia/0d900fa3-87c5-4b78-aae5-ff6a837f1a3a/an0006

aging on NP0 dielectrics is negligible, but that is at room temperature. 
Interesting on the concept of 'resetting the aging process' by bringing 
the dielectrics about their Curie Point. (including soldering)

Also, there is diffusion of impurities into the capacitors. Probable 
also means I should use thick film resistors.

But by the sounds of it, the crystal will dominate the aging process.

On 9/12/2023 1:09 pm, Ed Marciniak wrote: