Could be an RF, but the close I can find is an RFID from signal id wiki.

I also attached the IQ file if someone interested -> https://drive.google.com/file/d/1_Ntxyfb5yhE2UPkD41Rjaak4bLo8zvnN/view?usp=sharing

It's also nearby the 2g uplink/down (i assume it's 2g due to it's form): https://www.reddit.com/r/signalidentification/comments/1xckv8a/comment/19rhlsr2fkijm/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

i saw this MFSK signal appearing everywhere in the military air band. does anybody know what this is? if so, okease tell me

Riverside, California 9PM

crossposting, used the KiwiSDR receiver in Oita

Got two odd signals on the 8 MHz maritime band, RTL-SDR V4, 20 Oct ~02:00 UTC, northern Vietnam.

8420.9 kHz: bursts of fast tone hopping, about 11 tones with exactly 50 Hz spacing, roughly 50 baud by my estimate. Each burst is followed by a steady single tone, and the whole thing repeats about every 18 s.

8431.0 kHz: continuous, two lines exactly 200 Hz apart, ~300-400 Hz wide. I'm wondering if it's CIS-50-50 / CIS-36-50 idle, but I haven't decoded anything.

Both seem to sit on the same 50 Hz grid, so maybe the same system. Not on sigidwiki as far as I can tell.

Anyone recognize these? thanks

Raw IQ file: https://limewire.com/d/hSZV1#MVEUALrAgJ (it will expire in 3 days, lmk if someone needs it after that )

is that DMR simplex ?
and why i can't decode it ?

Any ideas folks? Sorry for "low effort post," this is really irking me and the AI is stumped.

4.866 MHz, sounds like ocean waves almost as the signal sweeps, possible OTH radar?

Captured from a Geostationary communications satellite using a bladeRF and a Ku-band LNB. Not TV channels.

Is there any software decoder available for any of these signals? Or something that will let me see the constellation diagrams? I am more interested in the signals other than the DVB-S2 (probably) outroutes. If there's any way to classify any features or get anything from decoded packets or maybe decode DVB-CID, I'd really love to try it.

Found this randomly.

I think this works for here

I’m trying to identify a radio signal I received using an SDR.

• Frequency: 151.550 MHz
• Observed bandwidth: Approximately 8.5 kHz
• Receiver/software: SDR++
• NFM audio: A continuous rough buzzing sound, something like “brrrrrrrr”

Heard at around 0:00 UTC an hour and a half ago. Anyone know what this is?

Frequency: 446.5 MHz

Received with RTL-SDR (R820T) + SDR Console v3.4, N-FM, about 10 kHz wide, homemade QFH 436 mhz antenna.

Signal strength about -100 dBm

Pulses exactly once per second, about 0.5 s on and 0.5 s off. No speech and no clear tones, only wideband hiss in the audio.

RTL_433 gives no output.

EDIT: signal was received in Denmark

UPDATE:

Not a weather balloon, same strength this morning.

From Claude.

• Two transmitters, alternating (half-duplex TDD). A and B take turns every 0.5 s, so each one transmits once per second.TX A TX B Burst length 363 ms 399 ms Rel. level +19.1 dB (±0.8) +13.5 dB (±0.14) Freq. offset −1.25 kHz +1.45 kHz The two are about 2.7 kHz apart, which is roughly a 6 ppm crystal difference. That's why the spectrum looked double-humped.
• Modulation: 2-FSK at 4800 baud, about ±3 kHz deviation, inside a 12.5 kHz channel.
• Frame structure:
  • a 1010 preamble (about 185 bits on A, about 300 bits on B),
  • a sync pattern of 00001111 repeated ×8,
  • a short header,
  • about 1500 bits of payload that looks random (scrambled or encrypted).
• No TDMA slots inside the bursts, so it's not DMR or TETRA. The bursts show no chirps, so it's not LoRa either.
• Throughput: about 1.5 kbit/s each way at a fixed duty cycle.

UPDATE II:

IQ files can be found here:

Angry-Racoon-Tech/SIGINT: SDR related files

What is this massively wide buzzer signal around 10.280- 10.340, with peak around 10.325? Picking it up in various SDr’s too which rules out local RFi. S9+ out of Nashville, TN

Hey
I am curious to identify this signal especially there is line between bursts in beginning of the video , every morning broadcasting .

So I can't find a decent website that I can cross check previous satellite pass (maybe I'm bad at it and can you provide me one?).

Also I assume this is a satellite due to the doppler shift effect, but correct me if this is something else. I captured it 12:26:14 UTC, Oct 4 2026

What could this be?

EDIT: Radiosonde

There is this signal which can be heard across various frequencies in the HF range; I’ve heard it multiple times while dx-ing.

Does anyone know what it is?

Picked up these two very strong signals just now on a homebrew radio. Exactly 7kHz apart at 6.9635 and 6.9705 MHz. Individually they sound a bit like CW, but the tone is different and the timing is wrong, very 'mechanical' and repetitive. I can pick them up on online SDR radios pretty much wirldwide ChatGPT said the same signal pair was reported back in May and was suspected as being an FSK signal of possibly military origin but not confirmed?

I can't upload the recording or video, but here's the signals seen on on online SDR waterfall.

This weird interference appeared on the FT8 40m band around 7074 kHz tonight. The software is SDR Oxide for those who are interested.