Category: Applications

TechMinds: Demonstrating the QT-DAB Digital Audio Broadcast Decoder

Over on YouTube TechMinds has uploaded a video where he explores the QT-DAB software (formerly known as SDR-J), which is a program capable of decoding Digital Audio Broadcast (DAB) signals. QT-DAB is compatible with several SDRs including the RTL-SDR, HackRF, Airspy and SDRplay units. 

DAB stands for Digital Audio Broadcast and is a digital broadcast radio signal that is available in many countries outside of the USA. The digital signal encodes several radio stations, and it is considered a modern alternative or future replacement for standard analog broadcast FM.

In the video TechMinds explains how to download, install and use the software on a Windows machine. He goes on to demonstrate some DAB decoding in action with various SDRs and then shows how to connect QT-DAB to a remote RTL-SDR via rtl_tcp.

DAB Radio Decoder For SDR (RTL_SDR - HACKRF - AIRSPY)

Broadcastify Calls: Radio Call Archiving + Incentives for SDR Software Developers

Broadcastify is a large scanner audio streaming site which provides live audio streams of Fire, Police, EMS, Aircraft and Rail communications across the USA and in many other countries. These streams are all provided by volunteers running scanners and software defined radios like RTL-SDRs in their local areas.

Recently Broadcastify have announced the beta of their "Calls" platform. This allows them to provide not only live streams of audio, but also an archived history of every radio call received. We believe that this is a technology similar to Radiocapture. The service advertises 30-day call retention, duplicate call handling, live call playback, playlists playback, tight integration with the RadioReference database and detailed statistics of the call and source.

Currently you can contribute received calls to Broadcastify via the Trunk Recorder software. However, Broadcastify recently wrote in and wanted our readers to know that they are providing incentives to SDR software developers to adapt their software in order to allow calls to be ingested into the Broadcastify Calls platform. 

We're announcing developer incentives for the Broadcastify Calls Platform.

If developers adapt their SDR based application to function as a call ingest platform for Broadcastify Calls, Broadcastify will pay them up to $2,500 for their efforts. Here are the details:

  • To qualify for incentives, developers must apply and have an approved agreement with RadioReference.com/Broadcastify. Developers can request to be part of the incentive program by contact us at [email protected]
  • When first system comes online in production on Broadcastify Calls, developer receives a $500 USD check
  • When 5 systems come online in production on Broadcastify Calls, developer receives an additional $2,000 USD check

Documentation for the API can be found here:

https://wiki.radioreference.com/index.php/Broadcastify-Calls-API

Broadcastify Calls
Broadcastify Calls

YouTube Series on Inmarsat Decoding with Scytale-C

Paul (microp11) is the programmer behind the Scytale-C Inmarsat decoder which has become very popular with RTL-SDR owners. With Scytale-C, and RTL-SDR and an appropriate L-band antenna and amplifier it is possible to receive STD-C NCS data from Inmarsat satellites. This is a public broadcast which contains information like search and rescue (SAR) and coast guard messages as well as news, weather, pirate activity and other incident reports. If you're interested, we have a tutorial available here which uses different software.

Paul has recently created a 6-part video series explaining Scytale-C and all it's features. As well as showing how to setup a Scytale-C decoder with the SDR# plugin in order to receive the STD-C text data via the UI, Paul's series goes into more depth showing how to review and inspect the raw data packets, how to monitor multiple Inmarsat channels at once using SDR# Spyservers and how to use the map feature for plotting coordinate and region data.

Gorizont-rtlsdr: Another Linux OS Distro with Built in RTL-SDR Support & Software

A few days ago we posted about DragonOS, which is a Linux ISO file with several built in SDR programs that the creator Aaron has been working on during his COVID-19 lockdown period. We've now got a second lockdown inspired Linux distribution called "gorizont-rtlsdr" which was submitted by Steve Cox. The distro is based on Xubuntu 18.04 and focuses only on software for RTL-SDRs. Steve writes:

gorizont linux 1.0 is a live, USB bootable or VM .iso image, and my first attempt at sharing a project like this. It's built specifically for rtl_sdr/ RTL2832U family dongles, no other devices will be supported in the future (although drivers can be installed if required). It's meant for the cheapest, most available hardware out there.

I think there's a useful niche for this distro, Skywave Linux is getting a bit long-in-the-tooth and un-updated, and the recently reviewed DragonOS, whilst good, is a little complicated for beginners to use. gorizont concentrates on purely terrestrial HF/VHF/UHF analogue and digital signal exploration and decoding, hence the name. It also provides instant DAB+ and FM radio reception for emergency information using RTL V3 stock antennae.

It's built for customisation and compilation of evolving software, hence it's rather portly size. A pretty full suite of dev libraries and repos come as included. Users can also create a bootable USB image or .iso of an updated system using Systemback if gorizont is run as a VM.

We didn't see a list of programs preinstalled, but from the Readme it appears to have at least GNU Radio, GQRX, multimon-ng, DSD+, welle.io, PyBOMBs, wine32, sox, as well as a preset Virtual Audio sync set up through pulseaudio for piping audio between programs. We expect that many more programs will also have been preinstalled.

Easily Streaming SDR Output Audio through a Network to an Android Phone

Thank you to M Khanfar for submitting another video where he demonstrates and explains how to easily send audio from your Linux PC over to an Android phone. This can be used to monitor the audio output of SDR programs like OP25 and GQRX remotely. The main piece of software used in his setup is the SoundWire Server and SoundWire Android App. SoundWire is described below:

Turn your Android device into wireless headphones / wireless speaker. Stream any music or audio from your PC to your Android phone, tablet, or other PCs. SoundWire does audio mirroring (audio cast). You can use any music player on your PC or laptop like Spotify, YouTube, or iTunes and stream low-latency live sound over WiFi directly to your Android device. Also works over 3G/4G cell networks or WAN.

M Khanfar's full tutorial on how to setup SoundWire can be found in the description of the video.

Piping Op25-GQRX Audio Through LAN to Android Phone

DragonOS Updated: Now with OP25 Installed and many new YouTube Tutorials

Last month we posted about Aaron's "DragonOS" project, which is a ready to install Linux ISO aimed to make getting started with SDR software easy by providing several programs preinstalled, as well as providing multiple video tutorials. Recently he's updated the build, this time basing it on Lubuntu 18.04 allowing for Legacy and UEFI support, along with disk encryption. The OS supports RTL-SDRs as well as the HackRF and bladeRF and probably supports most other SDRs via the SoapySDR interface.

In terms of software he's also added OP25 and bladeRF support. Other programs pre-installed include rtl_433, Universal Radio Hacker, GNU Radio, Aircrack-ng, GQRX, Kalibrate, hackrf, wireshare, gr-gsm, rtl-sdr, HackRF, IMSI-catcher, Zenmap, inspectrum, qspectrumanalyzer, LTE-Cell-Scanner, CubicSDR, Limesuite, ShinySDR, SDRAngel, SDRTrunk, Kismet, BladeRF.

His DragonOS YouTube tutorial channel is also growing fast, with several tutorials showing you how to use DragonOS to perform tasks like listen to trunked mobile radios, use QSpectrumAnalyzer with a HackRF, receive NOAA APT weather satellite images, retrieve cellular network information via a rooted Samsung Galaxy S5, create a ShinySDR server with rtl_433 and how to capture and replay with a HackRF.

DragonOS running CubicSDR
DragonOS running CubicSDR

OpenEar Now Supports TETRA, DMR, POCSAG, ADS-B

Back in March we posted about "OpenEar" which was a newly released Windows TETRA decoder for RTL-SDR dongles. Back then the author "moneriomaa" noted that he planned to add several new modes. In the release that is currently available, OpenEar now supports TETRA, DMR, Pocsag, ADS-B as well as standard AM and NFM modes. We tested the software, and all modes appear to decode as advertised. In the future the author plans to add more modes such as MPT-1327 and AERO.

In the previous post we added an update noting that OpenEar appeared to be violating the GPL licence of OsmocomTETRA, and the author noted that he would remove the TETRA functionality until licencing was resolved. As TETRA decoding is back in the recent releases we assume these legal issues have been solved.

In the current release you also need to provide your own rtlsdr.dll file, which can be obtained from your SDR# folder, or directly from the Osmocom windows release (rename librtlsdr.dll to rtlsdr.dll).

Latest OpenEar Version
Latest OpenEar Version

Receiving SMOG-P and ATL-1 Nano Satellites with an RTL-SDR

Thank you to Zoltan Doczi (HA7DCD) for submitting his tutorial that shows how to receive signals from the SMOG-P and ATL-1 nano satellites which were launched via Rocket Lab back in late 2019.

SMOG-P is a Hungarian nano satellite developed by BME University. It's payload consists of an on board spectrum analyzer that is designed to measure electromagnetic pollution (electrosmog) from space, and to also monitor the DVB-T spectrum. It currently holds the title of the world's smallest satellite in operation.  ATL-1 is another Hungarian satellite this time developed by ATL Ltd. Its mission is to test a new thermal isolation material in space and to monitor the DVB-T spectrum.

To receive telemetry from these satellites you can use a Raspberry Pi, RTL-SDR, Yagi, and optionally an LNA and filter. In his post Zoltan shows how to install the SMOG-P decoder, and provides a script that automatically decodes, uploads packets to the BME University server, and archives old IQ files and packets.

We note that if you wish to receive these satellites, now is the time to do so as these nano satellites are in a very low orbit and only have an orbital lifespan of only 6-8 months total.

SMOG-P and ATL-1 Satellite Ground Station Receiver Setup
SMOG-P and ATL-1 Satellite Ground Station Receiver Setup