Dear all,

To follow up on "the other Wouter" PA3WEG's message: Delfi-C3 is expected to deorbit on the 12th or the 13th of November. See https://sattrackcam.blogspot.com/2023/11/delfi-c3-reentry-forecast-updates.html

The satellite has been observed transmitting on the primary (145.867 MHz) radio but sometimes also on the backup (145.930 MHz) radio. In fact, this morning I heard a brief burst of BPSK telemetry at 145.924 MHz (so about 6 kHz off-frequency assuming that this was the backup radio indeed), the suspicion is that this frequency drift is due to the satellite getting warm! So it pays off to tune around the expected frequencies during an overpass these days.

The oscillators on board are crystal oscillators, and not just "ordinary" crystal oscillators but instead of the relaxation type. Wouter PA3WEG championed these oscillators as part of his graduation project. They have some degree of temperature dependency (pun intended), and higher temp results in lower frequency. Apologies therefore for any interference, it should only last a few days hi :)

If you manage to receive and decode telemetry, don't forget to submit it for the "last telemetry frame" competition.

Thank you Delfi-C3, and it's truly been a privilege to work on this satellite with a fantastic team!

73,

Wouter Jan PE4WJ