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.
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.
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:
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 🙂 !!