[time-nuts] Re: pulling some crystals

[glen english LIST]

thanks Rick, Bob

which said aging going both directions..... If i can going to drive 
temperature  on the crystal to deal with this IE board temperature will 
be between 30deg C and 60 deg C, then I am going to have a tough time 
dealing with this  . IE having the crystal live between 60 deg C and say 
100 deg C.

  But  aging direction is not absolutely known.  The  angle of the cut 
etc needs to be chosen to cover all the bases, and this just might not 
be possible.

groan.  Remember, this doesnt have to be super stable- it will be pulled 
against a 10 MHz TCXO or GPS in the system.

Look at (one of ) the charts, something that has a turning point (TP) of 
70 deg C would be - 15ppm at 70C and + 15 ppm at 110 C ... or if _/- 10 
ppm is enough, -10ppm at 60 C and +10ppm at 100C.

etc.



On 12/12/2023 1:18 am, Richard (Rick) Karlquist wrote:
> Great summary Bob.
>
> Just wanted to amplify your point about the "dominant effect" syndrome.
> When I was young and foolish 50 years ago, I believed the folklore
> about Colorado Crystals "magic" glass enclosures:Â  unlike "dirt