SDRangel is a free open source software defined radio program that is compatible with many SDRs, including RTL-SDRs. SDRAngel is set apart from other programs because of it's huge swath of built in demodulators and decoders.
SDRAngel is a general purpose software defined radio program that is compatible with most SDRs including the RTL-SDR. We've posted about it several times before on the blog, however we did not realize how much progress has occurred with developing various built in plugins and decoders for it.
Thanks to Jon for writing in and sharing with us a demonstration video that the SDRAngel team have released on their YouTube channel. From the video we can see that SDRAngel now comes stock with a whole host of built in decoders and apps for various radio applications making it close to an all-in-one SDR platform. The built in applications include:
ADS-B Decoder: Decodes aircraft ADS-B data and plots aircraft positions on a map
NOAA APT Decoder: Decodes NOAA weather satellite images (in black and white only)
DVB-S: Decodes and plays Digital TV DVB-S and DVB-S2 video
AIS: Decodes marine AIS data and plots vessel positions on a map
VOR: Decodes VOR aircraft navigational beacons, and plots bearing lines on a map, allowing you to determine your receivers position.
DAB+: Decodes and plays DAB digital audio signals
Radio Astronomy Hydrogen Line: With an appropriate radio telescope connected to the SDR, integrates and displays the Hydrogen Line FFT with various settings, and a map of the galaxy showing where your dish is pointing. Can also control a dish rotator.
Radio Astronomy Solar Observations: Similar to the Hydrogen line app, allows you to make solar measurements.
Broadcast FM: Decoding and playback. Includes RDS decoding.
Noise Figure Measurements: Together with a noise source you can measure the noise figure of a SDR.
MMDVM is firmware that normally runs on an ARM microcontroller board such as the Arduino Due, and is designed to be interfaced with hardware radios via the microcontrollers built in ADC and DAC hardware.
In order to use an SDR instead of physical hardware radios, Adrian's article describes how a fork of MMDVM called MMDVM-SDR is used in his system as this allows the code to run on a normal Linux computer with an SDR. GNU Radio running on Adrian's own QRadioLink software is then used to create software ADC/DAC interfaces for the SDR and MMDVM-SDR to interface with, as well as providing a user interface.
Sarah from the SignalsEverywhere YouTube channel is back and this time showing off a new program she has created called "Pi25" or "OP25 Mobile Control Head". The program is a Python GUI for OP25 which runs on almost any platform including Android and Windows. OP25 is an advanced open source digital voice P25 Phase 2 capable decoder which can be used with an RTL-SDR and run on a Raspberry Pi.
Sarah's GUI software allows information from the OP25 software to be displayed on a nice large Android tablet screen, as well as having scanner forward/back buttons, and talkgroup skip and hold controls. This is very useful for in-car control on a mobile setup.
Sarah notes that she is also considering running a Kickstarter for a physical hardware OP25 head unit controller so please let her know in the YouTube video comments if you are interested.
In his latest episode of his SDR Guide series Rob from Frugal Radio provides a walkthrough on using DSDPlus Fastlane to decode trunked P25 with just one RTL-SDR V3 dongle. In the video he explains each of the various DSDPlus windows, and demonstrates decoding of a Simulcast system in his area.
DSDPlus is a program capable of decoding various digital audio protocols such as DMR and P25. The "Fastlane" version is a $25 paid upgrade which allows you to download the latest version that contains more features.
2021 SDR Guide Episode 9 : $25 DSDPlus P25 LSM trunking walkthrough using 1 x $25 RTL-SDRv3
At the beginning of 2020 Annunaki (@StupotSinders) released his third party user interface for DSDPlus. DSDPlus is a digital speech decoder capable of decoding protocols such as P25 P1, DMR, NXDN and more with an SDR such as the RTL-SDR. As it is a command line tool, it can be a little daunting for some users, which is where the GUI comes in handy.
Recently Annunaki has released an SDR# plugin version of DSDPlusUI. This makes it so you can visualize the digital voice signals at the same time as controlling and decoding with DSDPlus. The plugin is available on the DSDPlusUI website at dsdplusui.com. To use it you will need to be using SDR# 1777 or later.
Vasili, author of several SDR# plugins has recently released a new APCO P25 plugin for SDR#. The plugin is easy to use, simply tune to a P25 voice signal, and it will automatically decode it into voice audio assuming that the signal is not encrypted. If the P25 signal is encrypted, you will hear garbled unintelligible voice. The plugin does not support trunking or any advanced talk group filtering features that you might find with DSD+, Unitrunker, SDR Trunk etc.
To install the plugin, simply download the zip file from rtl-sdr.ru and extra the .dll's into the SDR# folder. Then copy the text in magicline.txt file into the plugins.xml file inside the SDR# folder. The plugin should work with any SDR supported by SDR#, including the RTL-SDR.