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.
Thank you to reader Jon for writing in and noting that SDRangel has recently been released for Android as a free Google Play download. This is an amazing development that could open up many doors into portable decoding setups as the Android version supports almost every decoder implemented on the desktop version. Jon writes:
It includes most of the functionality of the desktop version of SDRangel, including:
AM, FM, SSB, Broadcast FM and DAB, AIS, ADS-B, Digital Voice (DMR, dPMR, D-Star, FreeDV), Video (DVB-S, DVB-S2, NTSC, PAL), VOR, LoRa, M17, Packet (AX.25), Pager (POCSAG), Radiosonde (RS41), Time signal (MSF, DCF77, TDF and WWVB) modems.
RTL SDR, Airspy, Airspy HF, LimeSDR, HackRF and SDRplay support via USB OTG as well as networked SDRs
2D and 3D signal analysis in both time and frequency domain with statistical measurements of SNR, THD, THD+N, SINAD, SFDR and channel power
Satellite tracker, star tracker, maps and rotator controller
It should work on Android 6 and up. It’s a straight port of the desktop application, so although it will run on a phone, probably best used on a large tablet with a stylus or mouse.
In December of last year we posted about a video demonstrating the many features that the SDRAngel software comes standard with. Recently they've added a new feature which are 3D maps that can be used to visualize signal data.
In the latest video demonstration they show these 3D maps projecting NOAA weather satellite images onto a 3D globe and at the same time tracking the NOAA satellites over the globe as it produces imagery. They also show the software visualizing a 3D model of aircraft on the globe, using live ADS-B data to show aircraft maneuvers when taking off, cruising and landing. With multiple SDRs they also show how the visualization can be combined with air traffic voice. Finally they also show marine vessels being visualized via live AIS data. There appear to be a wide range of vessel 3D models implemented.
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.
Graves Radar Tracker: For Europeans, track a satellite and watch for reflections in the spectrum from the French Graves space radar.
Radio Clocks: Receive and decode accurate time from radio clocks such as MSF, DCF77, TDF and WWVB.
APRS: Decode APRS data, and plot APRS locations and moving APRS enabled vehicles on a map with speed plot.
Pagers: Decode POCSAG pagers
APRS/AX.25 Satellite: Decode APRS messages from the ISS and NO-84 satellites, via the built in decoder and satellite tracker.
Channel Analyzer: Analyze signals in the frequency and time domains
QSO Digital and Analog Voice: Decode digital and analog voice. Digital voice handled by the built in DSD demodulator, and includes DMR, dPMR and D-Star.
Beacons: Monitor propagation via amateur radio beacons, and plot them on a map.
We note that the video doesn't show the following additional features such as an analog TV decoder, the SDRAngel "ChirpChat" text mode, a FreeDV decoder and several other features.
Over on his YouTube channel SignalsEverywhere, Corrosive has uploaded a new video tutorial showing us how to transmit with a PlutoSDR and SDRAngel. His tutorial goes over the initial set up steps, selecting a modulator and changing modulator settings. He then goes on to demonstrate transmitting CW Morse code, using a CTCSS squelch tone and transmitting a Robot36 SSTV image via Virtual Audio Cable and MMSSTV.
Over on his YouTube channel SignalsEverywhere, Corrosive has posted a new video tutorial explaining how to use the SDRAngel software for receiving signals in Windows. SDRAngel is a general purpose SDR program similar to programs like SDR#, HDSDR and SDR-Console, however it's layout and workflow is slightly different compared to other programs. SDRAngel also has some interesting features such as built in decoders for DMR, D-Star and Fusion digital voice signals and unlike most other general purpose SDR programs, SDRAngel is also capable of controlling transmit capable SDRs. Corrosive notes that he will discuss that feature in a future tutorial.
Corrosive's tutorial goes over the main points such as changing gain, changing sample rate, tuning to signals, and adding demodulators. In the video he uses an RTL-SDR as the receiver.
RTL SDR SDRAngel Tutorial - How to Receive Basics and More
At the end of last month we uploaded a post highlighting the SDRAngel software, which is a general purpose SDR program with some interesting features such as built in digital speech decoders for DMR, D-Star and Fusion. This avoids the need to pipe audio into a separate digital speech decoder program such as DSD+. SDRAngel also has transmit capabilities which makes it useful for SDRs such as the HackRF, PlutoSDR, LimeSDR etc.
Now over on YouTube and his blog K2GOG has uploaded a video tutorial about using SDRAngel. The tutorial starts with installing SDRAngel and explaining that you'll need a 64-bit system and OS to run it. He then goes on to show how to do FM reception and finally how to do digital speech decoding.
SDRAngel is a general purpose SDR program similar to other programs like SDR#, HDSDR and SDR-Console. It is compatible with Windows and Linux systems. However, SDRAngel has certain features that make it a good program to have in your SDR software arsenal.
One good feature is that if you have a TX capable SDR like a HackRF, PlutoSDR, BladeRF or LimeSDR then SDRAngel can also be used for TXing. Marty Wittrock has done a lot of previous work figuring out how to TX with LimeSDR and SDRAngel.
If you're only interested in RXing then SDRAngel also has some convenient features such as a built in DSD decoder which can be used to easily decode DMR/MOTOTRBO, dPMR, D-STAR and Yaesu System Fusion (YSF). The decoder is based on the DSDcc library which is a complete rewrite of the original open source DSD software. It is not quite as developed and feature rich as DSD+, but still does the job decently. SDRAngel also has LoRa and analogue TV (ATV) decoders built in as well, although the ATV decoder kept crashing the software for us.
SDRAngel also supports multiple VFO's on the same bandwidth, has built in decimation, a nice phosphor effect RF spectrum display and a frequency manager. There is also the ability to run multiple SDRs in the same software instance at the same time.
We gave SDRAngel a try on Windows and were able to easily get it up and running with an RTL-SDR. Regular WFM, FM, AM, SSB etc modes all work fine and so does the DSD decoder which we tested on a DMR signal. Getting it to decode was extremely simple, just add a DSD Demodulator channel, then click on the signal and you should be instantly decoding. It is probably the easiest way to get started on decoding a non-trunking digital voice channel, but for trunking channels and P25 signals you should probably still use Unitrunker and DSD+ or SDRTrunk.
Below is a brief tutorial on getting up an running with SDRAngel on Windows with an RTL-SDR:
Download the latest version of SDRAngel from the releases section of the GitHub. Only a build for Windows x64 is available and this has the filename sdrangel64_v3.8.4.7z (version number may change in the future). Linux .deb files are also available for various Ubuntu versions.
Using 7zip, extract the 7z file to a folder on your PC.
Plug in your RTL-SDR dongle, and run sdrangel.exe. We assume zadig has already been previously run to install the RTL-SDR drivers.
On the left under 'sampling devices control' click on the small hand icon. A drop down box will pop up, and from here you should be able to select the RTL-SDR. Press ok.
Now you can click the green play button on the top left to start the SDR.
By default the display bandwidth is zoomed in very closely with x16 decimation and a sample rate of 1 MSPS. So in the top left box change "Dec" to 1, and increase the sample rate to 2 or 2.4 MSPS if you like.
We suggest also clicking on the 'DC' button in the top left to remove the DC spike.
Now you can tune around just like in other software by using the frequency numbers in the top left.
If you want a spectrum analyzer display, go to the bottom left box, and click on the blue spectrum icon.
Unlike most other software you need to add a demodulator first before you can click on a signal and listen to it. The list of available demodulators can be found in the second box on the left, just below the hand icon which you used to add the RTL-SDR.
Select the correct demodulator for your signal of interest (e.g. WFM, NFM, AM, DSD, LoRa etc...), and then click the "+" icon. This will add the demodulator to the right of the SDRAngel window. You may want to drag the right window a little large if you cannot see all of the demodulator option as well.
Now you can click on the signal in the spectrum window to move the VFO and begin demodulating the signal. You can explore the demodulator options on the right.
Multiple demodulators can be added if desired, just repeat steps 8 - 10. If you add more than one demodulator, the VFO's will need to be dragged.
If you're having trouble getting a digital voice signal with DSD to be recognized, try zooming in with the decimation feature or reducing the sample rate. It doesn't seem to work too well with higher bandwidths.
Over on the LimeSDR facebook group Marty Wittrock (KN0CK) has been experimenting with his LimeSDR and SDRAngel. SDRAngel is a general purpose SDR program similar to SDR#/HDSDR/SDR-Console etc, but with the key difference that it is designed to incorporate TX features as well. SDRAngel has releases available for Linux and Windows.
Marty writes that in early August SDRAngel programmer Edouard (F4EXB) resolved most of the issues with LimeSDR compatibility and now TX and RX in SDRAngel with the LimeSDR works great.
SDRANGEL/LIMESDR WINDOWS UPDATE – WORKING!: …For the first time in 18 months the LimeSDR has a working Windows transmit and receive application..! Check out the video for more, but for those that don’t use Linux, you can now experience full transmit and receive using the Win32 SDRAngel version 3.5.5 and Zadig 2.2 that loads the LimeSDR driver…Just load Zadig first as you normally would to select the LimeSDR (after you’ve initially installed it) and then launch SDRAngel…The application will allow you to operate ANYWHERE from 160m to 70cm using any demodulator and modulator you wish (AM, FM, SSB, CW, and more!). I tested it this evening from 40m to 10m to 2m tonight and it works EXCELLENT..!! Get in while the gettin’ is good – A full-up transceiver app now exists for the LimeSDR and this is just the beginning..! 73 de KN0CK
LIMESDR/SDRANGEL UPDATE: Yours truly the mad scientist, playing with the LimeSDR on HF at 7.0 MHz here within the shack (no external antennas applied) TRANSMITTING NO DELAY ON HF LOWER SIDEBAND USING SDRANGEL AND THE LIMESDR..!! FINALLY, an app that supports receive and transmit for the LimeSDR is available free of charge and WORKS PERFECTLY..!! See it for yourself on the attached video…And I do have the recipe for this since it’s on Linux (Ubuntu 16.04) for now…A Windows 7/10 build IS planned…A RED LETTER DAY FOR THE LIMESDR..!! #LimeSDR #SDRAngel #HF 🙂 !!