I stumbled across this product listing: https://www.teradak.com/products/115.html
It's a Pi hat that contains two TCXOs, one at 19.2 MHz for the CPU and one at 25 MHz for the Ethernet controller. It's a rather permanent modification, as you have to desolder the stock crystals and replace them with wires going to the hat. I'm not 100% sure how to order the hat yet, but they gave a price of $46 (USD) via email. I'm curious if this would provide any meaningful improvement in system clock accuracy, for NTP, if I'm already a GPS PPS hat. If there's a reasonable chance this could be interesting, I'm thinking about ordering a couple and "sacrificing" a Pi 3 and/or Pi 4. In terms of mounting both hats, I'm guessing that the TCXO is only using power from that hat connector, so rather than use the hat connector, I would just solder some wires to it and the Pi, such that I could stack the TCXO on top of the GPS hat physically but not need to connect them electrically. -- Richard _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.