Replacing the original ±20ppm crystal with a ±0.2ppm TCXO.
Raspberry Pi StackExchange Post:
https://raspberrypi.stackexchange.com/questions/74482/switch-out-the-x1-oscillator-on-a-rpi-2-3/109074#109074
New part:
https://www.digikey.com/en/products/detail/taitien/TXETBLSANF-19-200000/6127626
Stock Pi Crystal:
https://www.farnell.com/datasheets/2860337.pdf
