[time-nuts] time-nuts Digest, Vol 188, Issue 22 Re. Pi

[Andre]

Hi, what about using an SDR to micro adjust the 19.2 MHz crystal?

I found that replacing the input capacitor (normally 18-27pF) with a reversed blue SMD LED seems to help.
Simply pick an LED with the desired reverse capacitance and test.
Also feasible: add a 10pF C0G as well if the frequency is too far off to trim in this way.
https://www.newark.com/capacitor-types-and-performance

Note that most blue LEDs are light sensitive to UV so plan accordingly.