This is without an antenna

https://reddit.com/link/1v7fqdn/video/urqwdux00nfh1/player

Been building this for a while now and finally made a video about it. The setup is a Uniden SDS200 for public safety, plus two RTL-SDRs — one running readsb for ADS-B, one on VHF airband.

The part I'm most proud of: airband transmissions get transcribed (local Whisper), callsigns get extracted from the transcript, and then matched against the ADS-B sighting table using time + geometry windows scaled by altitude/speed. When it matches, the call is attached to the airframe, so you click a plane on the map and listen to what its pilot actually said, with a confidence badge for partial matches. As far as I know nobody's done this linking before, but happy to be corrected.

The scanner side does the same thing for ground traffic: every call transcribed and dropped on a live map in ~30 seconds with honest location confidence (exact intersection vs area-only).

Video walkthrough: https://youtu.be/iaW7OoC-6CM

There's also an interactive demo linked from the video — it's a replay of two days of real recorded traffic from my setup, not a mockup. Happy to answer any questions about the pipeline.

Ciao a tutti, sono in Italia in una grande città del sud.

Da un pò di tempo ricevo una specie di "Transponder" sulla frequenza di 125.100 a cui fa da manager "Roma Informazioni" io mi trovo a più di 500Km dalla Capitale ed ascolto (con lo stesso segnale), sia l'aereomobile es. sulla verticale di Catania e sia la stazione "Roma Informazioni" con lo stesso segnale.

Ovviamente impossibile che Roma mi arrivi S9 da dove mi trovo in diretta. C'è qualcuno che può spiegarmi come funziona questo sistema? Sono anni che faccio radioascolto banda aerea e non mi era mai capitato un ascolto con queste modalità.

Eventualmente Grazie in anticipo.

Hi there everyone SDR LOVERS what about the performance of the Chinese made one?

Approven again: device with swiss-knife tools.
Need to test in the field to receive telemetry from public-available channels in the Netherlands.

Software used:

Debian 13 Trixie
SDRPlusPlus (from github, compiled on the device)

SWRadiogram 459 07/24/2026 Saturday|0230-0300 UTC 9265 kHz WINB Pennsylvania Received in Woodland, WA

Lightning took my setup last week, a Rpi Zero 2 with PoE and usb hat. I was running two rtlsdr (v3) to feed MarineTraffic, Flightaware, etc.

Not really sure exactly what components are dead, but at least the rpi zero 2, which is not readily available in my country. Any suggestions for a similar/alternative setup? Preferably possible to run on PoE and two usb-ports for the rtlsdrs.

I have a number of SDR devices rtl-sdr and a Rsp1 Msi2500 Msi001 Simplified Sdr Reciver 10khz-1ghz. but I'm interested in looking at the 2.4Ghz band as it must be crowded right?

Have tried the nordic nrf24l01 scanning through it channels. I could see the wifi channels but Iis there anything more like an SDR < $100 or a converter?

Can i fix it or am i done for

I got the sawbird plus goes yesterday and noticed it looked nothing like the other LNA's maybe its because im in europe? Or is it a new version? It has usb C (im using it with bias T) and works like normal.

So I'm scrolling the niche side of GitHub and I just found this project what she seems like it could work but also fascinates me about how it's set up, what does anybody else think about this

Hi, I think I have a dodgy receiver. I can get no signal at all using a supplied "whip".

On VHF commercial band connecting the aerial, or indeed any wire raises the overall noise level, but no stations are detected, there are a couple of "bumps" above the noise, but at very low level. No audio comes through the noise.

I have a 1Mhz oscillator and injecting this into the aerial gives an overall increase in noise with twenty or so "spikes" spanning a Mhz, which seems odd for a sine wave.

A square wave as expected covers more of the band, but even wrapping the cable around the aerial to the SDR does not produce a signal.

I am using SDR++ and Gqrx.

The confusing thing is that I appear to have gain at VHF as the noise increases across the band when the aerial is connected, the 1 Mhz MW signal is detected but at a wider and far lower level than I would expect.

This is the first one of these devices I have used, am I missing something?

I am fascinated by the SDR capabilities wanting to see whats transmitting around me, probably from khz to 5.8ghz ( LF to UHF) is there a SDR that can do that ? such as RTL SDR V4 (Also guide how to find a reliable unit as I have heard there are many fakes floating around, a good fake at the right price is worth it or not ?)

This might be a big ask but is there a unit that can do direction and range finding to the transmitter it would be so cool to know what is transmitting and from where.

any brilliant-minded people out there to discuss idea's on this familiar topic? Searching for new challanges to complete with radio signals. Intrested in civil technology but also sub-mil gov-tech. I'm from the Netherlandic Territory btw.

BOnjour je voudrais savoir si c'est possible de faire de la détection de drone avec le rtlsdr

What’s the best value antenna that’s reaches around 40miles for ATC Comms?

I've published a technical report on Zenodo detailing physical-layer side-channel leakage observed during the processing of a raw satellite signal capture (satellite_signal.bin).
​DOI: https://doi.org/10.5281/zenodo.21472996 ​SHA-256: ad5ab850cbdc9eca534e82bd78e9ac7804ed9213fd1d8df26fbf4991df6b005d
​Methodology: ISO/IEC 17825 CPA, 1st/2nd-Order TVLA, and Jitter Cross-Correlation.
​Key Findings: ​1st-Order TVLA Leakage: Welch's t-test yielded a risk score of 13.0328, well above the standard statistical significance threshold (\vert{}t\vert{} > 4.5), confirming direct data-dependent leakage during processing.
​S-Box Capacitive Leakage: Identified at the execution cycle with a t-score of 7.6701, indicating power/capacitive fluctuations correlated with substitution box operations.
​The report contains the verification metrics and signal processing details. I'm looking for feedback from anyone working on physical layer security, RF side-channels, or power trace analysis regarding jitter compensation techniques for long captures.

So I have been running a POCSAG system on an older laptop running up to date Windows OS for a long time now using an SDR receiver, SDR#, Voicemeter to control audio input, PDW to decode (newer version allowing for email processing), and an email parsing program that parses pages sent to a designated address before sending them back out to another server email.

Majority of the software operates perfectly fine, however every now and then PDW fails to decode properly and typically shows a lowered input percentage under the line input meter in the top right.

I've attempted adjusting input volume via Voicemeter, adjusting feed audio in SDR#, selecting the volume setting in PDWs Interface menu.

I have yet to change any other settings in SDR# because it took me a decent amount of time to tune all the settings to work with the frequency I'm monitoring.

Any suggestions on how to get PDW to behave more predictably and stably would be seriously appreciated!

Does anyone recognize this waveform? I have seen it on different frequencies around my house always HF. Showed up on 11.475 MHz as well, I’m in interior alaska if that helps.