Observation 12459687: HUMSAT-D (39433) What is this?

dana · September 28, 2025, 10:43am

I am getting this trace regularly and can not identify it. It was suggested it might be a weather balloon but I have ruled that out. This shows up from 400’s to 430’s mhz at all hours but it does not appear on every observation. I have a Public Safety Ohio MARCS trunked transmitter on a water tower about 200 yards away that is 700-800 mhz but I monitor that also and it is often not transmitting while the observation is recorded. The only thing I can guess is it is some kind of local data link.

Any other suggestions?

bali · September 28, 2025, 1:18pm

“Have you ever tried listening to it live directly from an RTL-SDR app?” maybe that will give you some clue.

dana · September 28, 2025, 1:29pm

I have a SDRPlay Duo that I scavenged the antenna from for an SDRTrunk instance. I might have to get another splitter and get it hooked back in to watch the waterfall from 400 to 470 and see what shows. Nothing pops up on my Yaesu FTM400 when I watched that