Where to start. The tl;dr is more delays, as the only prototype I had was lost yesterday on a mountain ridge and there is absolutely no way to find it.
The crashed happened after 1) The video transmitter software crashed (in a way that never happened before during development – I was so confident I didn’t have a watchdog enabled) and 2) RTL failed to work, even though I had tested it the day before.
The relatively good news is that I have a ground recording of the event I can share. It’s nothing to be proud of, but it’s the only video I have at the moment as I also discovered my external ground recorder will happily overwrite files saved during the previous boot. I feel like I keep blaming things on others, like having lost the flight from two days before (where at least the camera was showing less vibrations) but that’s not my intention.
Anyway, the video shows the system working at 10mW with omni antennas (2 dBi on the drone, 5 dBi on the ground) and reaching 600 meters at full data rate before decreasing it gradually until the software crash at 1.7 km. In theory the system still had ways to go as the sensitivity limit wasn’t reached, but I can’t say for sure what that would have looked like, yet, as I’m not giving up.
I will leave you with a narrated video of the test.
I’ve now ordered a new transmitter PCB that should be here on Saturday if it’s not delayed at the factory. If everything else goes perfectly well I should be up in the air on Sunday for the next tests, that are 100 mW, 1 W and finally 1 W with yagi antennas.