[time-nuts] Re: Custom Quartz crystals

[Richard (Rick) Karlquist]

It is hard to answer your question.  The tuning range
depends on the varactor(s) used in the respective
oscillators, and the range of the tuning voltages.
I think I could roughly say from memory that putting
in a crystal meant for the other oscillator would
probably result in not being able to reach 10.000000
MHz.  Or just barely reaching it and having no
aging margin.  I had to apply a lot of arm twisting
to Jack Kusters to get him to make the series
resonant (at 10 MHz) crystals.  I made sure that
this was really necessary before going to war on it.

Rick N6RK

On 8/14/2022 3:35 PM, Hal Murray via time-nuts wrote:
> 
> Richard (Rick) Karlquist said:
>> We actually used the upper turnover because the E1938 had to operate at
>> ambient up 85  degrees.  BTW, the E1938 crystals had to be calibrated for
>> 10.000000 MHz at series resonance, unlike the 10811 crystals which were
>> calibrated for 20 pF (IIRC).
> 
> How big is the difference between series and 20pF compared to the tuning range?
> 
>