Mark Jessop (VK5QI)2d ago
Well this was odd! Was listening on the 20m amateur band, and I spotted this signal on 14205 kHz USB. Looks a lot like LoRa (FMCW chirps, with different 'phasing' for modulation), but there's no actual LoRa hardware for HF. Signsl was contained within a 3 kHz channel. Possibly someone experimenting? Hopefully it's an open source mode...
Show threadMark Jessop (VK5QI)2d ago
Well, whatever it is, it's beaconing every 10 minutes, starting 4 min past the hour. It seems to alternate between data transmissions, and then just a ~16 second burst of unmodulated chirps (FMCW). I've also seen short and long transmissions.
Show threadF4IHX
@vk5qi weird that looks like chirp but usually Lora have those break in the ramp. Maybe some HF radar system ?
Mar 26 at 9:00amWeb