op25 VS multimon-ng

looks like it may not be able to do what I want it to do according to this. https://github.com/boatbod/op25/issues/184

I have no experience with DMR myself, but my understanding is that the Boatbod fork of OP25 has experimental DMR support, and I believe SDRTrunk software does, too.

Using OP25[1] with RTL-SDR dongles to implement scanners for trunking P25 radio systems on a computer. And as a sidebar to that, listening in on geographically remote public safety radio systems using Broadcastify[2]. It's basically the old "radio scanner" culture, but taken online and distributed worldwide. People listen to all sorts of stuff, but given my background as a former firefighter and former 911 dispatcher, my main interest is listening to public safety dispatch stuff.

That said, another commenter below mentioned modern "phreaking" and how it's become more radio centric... and while I won't admit to doing anything illegal, let's just say that there's some interesting stuff you can do / look at / listen to these days, especially with ubiquitous and inexpensive SDR hardware and related resources. See the recent story about the KrakenSDR passive radar stuff, and some of the papers that are out there about P25 security flaws, some of the automobile hacking stuff that's RF based, etc., etc. There's a fascinating world out there buzzing around on invisible electromagnetic fields... and you can tap into it with a $30 dongle and a Raspberry Pi (or your PC).

[1]: https://github.com/boatbod/op25

If it's P25 Phase I or Phase II then SDRTrunk might work. boatbod's op25 might be another option, but more complicated to set up.

I don't have a full guide for you, but I use https://github.com/boatbod/op25 for receiving and decoding P25 Phase 1 digital signals on the command line.

op25

If you are handy with Linux you can use an RTL-SDR and OP25 on a Raspberry Pi or really any PC. This is the page for the Fairfax trunked system https://www.radioreference.com/apps/db/?sid=6957. Any talkgroup with mode D can be listened to, mode DE is encrypted. If you want I already have config files made up for the police dispatch and fire/ems dispatch channels.

I have little experience with decoding radio signals so I don't know if any software decoders are expected to handle the clipping. I tried using multimon-ng and found that its UFSK1200 demodulator can get something out of the audio, but it also keeps repeating Error: stop bit is 0. Bad framing if verbose mode is enabled.

Sorry I gave wrong name, it is multimon https://github.com/EliasOenal/multimon-ng and is capable to decode:

It's likely that the signal is extremely strong. You can probably just pick it up with a short antenna indoors. I used MultiMonNG to decode. It's was pretty boring to be honest.

Give multimon-ng a whirl. This is CLI based, but can output what it decodes to a simple text file or hex data to do what you need with.

multimon-ng

POCSAG, FLEX (pagers), Morse, APRS and more with multimon-ng

multimon-ng for decoding various protocols.

Try this tool; https://github.com/EliasOenal/multimon-ng - It's CLI and you'll ideally want a Linux, but this can decode an awful lot more data modes like such.