Hey Stuart,
Indeed after looking at your temperature data, we could just compensate for temperature, this would not compensate if it was different to what we expect and adding a TCXO is not that complicated from what I understand. I have been doing some freezer tests with a temperature difference of 60c as you say and have compensated accordingly.
As long as the IARU and the Spanish authorities allow us to use a bandwidth of 41.7kHz or above we should be fine, I just passed my HAREC amateur radio operator exam yesterday and will contact the IARU once I receive my callsign, Problem is the Spanish authorities also need to approve the satellite before we apply to the IARU so we’ll have to ask both.
I’ll see what is the highest bandwidth we can use with them though 62.5kHz to 12kHz is something we would be comfortable with to leave some margin for error for ground stations.
Thanks for the suggestion!