Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [signal-identification]

Questions about identifying signals of unknown mode or origin.

If your question asks about a recording of an unknown signal, or a snapshot of a waterfall display, then this tag fits. This tag also covers topics like numbers stations.

The Signal Identification Wiki is an excellent resource for trying to identify signals based on their sound and/or appearance on your .

42 questions
6
votes
2 answers

Identifying signals in the satellite exclusive band

I have just started playing with SDR so I downloaded the relevant amateur band plan for my location, the UK. Tuning around I found things like POCSAG/FLEX pagers as expected and amateur radio (e.g. FM repeaters) at frequencies matching the band…
David
  • 286
  • 2
  • 9
5
votes
3 answers

Detecting signals using statistics

I have sampled a section of spectrum every few Hz. I have mean, standard deviation, and range data for every frequency sampled (and I can gather more statistics if necessary). I've sampled for several seconds before storing the spectrum…
Ken - Enough about Monica
  • 600
  • 2
  • 14
5
votes
2 answers

What are the continuous transmissions at the lower end of the spectrum?

I'm fairly new to amateur radio, and I've been using a web-based SDR tool in addition to my own radios. Using this SDR tool shows a lot of activity lower down on the spectrum, such as this: When I tune into it I hear a lot of odd sounds, some sound…
user9993
  • 153
  • 3
5
votes
1 answer

bizzare CW on 2m

I'm currently in Kershaw, SC. Yesterday an automated signal popped up on a 2m simplex freq (147.455 MHz) and has been running since. It sounds like Morse, but it is random letters that don't seem to have any repeating pattern. After every seeming CW…
Aaron
  • 51
  • 2
5
votes
3 answers

Unidentified signals on FT8 frequencies

When I work in FT8 mode I often see signals like these: I couldn't identify these signals using SigiWiki nor managed I to decode them using WSJT-X. Though these signals seem to use 15 second frames. They don't seem to be a noise created by stations…
Aleksander Alekseev - R2AUK
  • 4,262
  • 12
  • 48
4
votes
2 answers

What type of signal is this?

I received this signal around 7 MHz. I've checked all over the "Signal Identification Wiki", but cannot find anything similar to this. I'm pretty sure this is some simple FSK, but that is the exact type? The signal is at around 2200Hz (in audio…
Risahas
  • 41
  • 2
4
votes
2 answers

Very odd and wide 30m signal. What is it?

A local ham friend copied this strange, wide signal on 30 meters on his Flex 5000. Anybody know what it might be?
Mike Waters
  • 7,843
  • 4
  • 16
  • 50
4
votes
1 answer

What is this short, wide band signal?

I've observed a signal I'm unfamiliar with, and am wondering what it might be: The period of time it lasted is 5 seconds, and it occurs irregularly. You might be able to see it too via WebSDR. How would I discover what type of signal this is,…
Adam Davis
  • 12,095
  • 2
  • 45
  • 106
3
votes
1 answer

What is this Morse code-like station?

I’m trying to identify this signal at 928.807 MHz. A sample of the raw I/Q from gqrx is here (9.2 MB, .wav, 48000 Hz) and this is the waterfall: I’ve tried decoding some common digital modes (including CW) with fldigi but have not had success. I’m…
Henry Elliott
  • 133
  • 3
3
votes
1 answer

How do I go about identifying an unknown digital signal?

I'm playing around with an SDRPlay. I'm using the CubicSDR app, and I'm tuning around the HF bands. I get to 5.650 MHz and I see this: This looks like a bunch of discrete RTTY signals. How would I go about identifying and decoding some of these…
bcattle
  • 255
  • 2
  • 8
3
votes
1 answer

What might this "spreading" interference be?

Any idea what might be causing this signal to appear in the "panadapter" spectrogram of my Omnia SDR around the 40m band? Every twenty seconds, I get a strong "focused" signal that then rapidly spreads out its power — like all the power is…
natevw - AF7TB
  • 7,219
  • 2
  • 23
  • 58
3
votes
1 answer

Help on identifying signal type and extract audio from a signal

I Just recorded a signal using SDR++ and RTL-SDR. I can recognize even without any demodulation so I think it should be an AM modulation but AM demodulation doesn't give me a clear audio. I also tried NFM and got the same results (unclear audio) Can…
Ariyan
  • 143
  • 5
3
votes
1 answer

Zigzag line on CB band

I'm seeing this strange signal on the CB band around 27 MHz, at a glance it looks similar to NFM modulation, but it's just noise when tuned to. It's transmitted about every minute. My setup is RTL-SDR with Nooelec NeSDR and a "noise-cancelling…
MightyPork
  • 145
  • 5
3
votes
1 answer

Fourier transform of air breakdown impulse waveform

i am a beginner on signal processing. I learned from some papers, site online, including this forum that lightning discharge or any electrical arc emits wideband radio frequency. because the odd integer harmonic of a square wave. and electrical arc…
Ramanda Nvl
  • 129
  • 6
3
votes
1 answer

Open source RS41 decoder

I would like to decode the signal from a RS41 radiosonde (from a weather balloon), which are suggested open-source software to do that? I tried RS but after compiling the code and executing sox wav/20140717_402MHz.wav -t wav - lowpass 2800…
Paa
  • 33
  • 3
1
2 3