Thank you to Adrian for submitting his video about using the Android App called QRadioLink and an RTL-SDR to decode digital amateur radio voice transmissions. Adrian writes that in the video the RTL-SDR connects to the Android phone with a USB OTG cable and uses a sample rate of 1 MSPS. He also writes the following about QRadioLink:
QRadioLink is a building platform which allows experimenting with VHF-UHF SDR transceivers using different modulation schemes for digital data transmissions. So far digital voice and text transmission is supported, using either a narrow band modem and Codec2 or a high bandwidth modem and Opus. Supported hardware includes the RTL-SDR, Ettus USRP, HackRF, BladeRF and in general all devices supported by libgnuradio-osmosdr.
Over on Twitter @lambdaprog and @mm6dos, developers of SDR# and Airspy SDR products have tweeted videos showing off an Android watch being used as an SDR interface. They use a prototype of their upcoming Airspy HF+ SDR, their SpyServer streaming software and an Android watch. The Android watch receives the streaming FFT and audio data from a server running the SpyServer and Airspy HF+.
They write that this new SpyServer client is mainly for phones and tablets and is efficient enough to run on a watch. It appears that this lightweight version of the SpyServer sends compressed FFT and audio instead of a slice of the IQ data like the current SpyServer, making it very light on the client side CPU and network usage.
If you’re interested in the Airspy HF+ we have an initial review available here.
Last month we posted about Aerial TV, a new Android based DVB-T decoder that works with RTL-SDR dongles. Back then the app was still in beta testing and had a few operational bugs. Now the Aerial TV app has been officially released.
UPDATE: Due to Google policies Aerial TV has been removed from the Google Play Store. It is claimed that Aerial TV could be used for copyright violation. It is now available on the Amazon store. Official information will always be available on the new official website at aerialtv.eu.
The app is based on the new Android DVB-T driver for RTL2832U devices which is written by Martin Marinov who is also the programmer of Aerial TV. The DVB-T driver is open source, and currently supports RTL2832U devices with the R820T, E4000, R828D, FC0012 and FC0013 tuner chips. Of note is that the R828D also has DVB-T2 support.
Aerial TV is free to download and test, but requires a $7.99 licence to use for more than 30 minutes. To use it you will need an OTG (On-the-go) cable adapter and an RTL-SDR dongle with antenna.
Just watch TV – no data plan or wifi connection required. Aerial TV works by picking up digital TV channels off the air with a regular TV antenna.
You will need a low cost USB TV tuner. You can grab one online for less than €10. Make sure to get an RTL2832 tuner. When it arrives, just connect the provided antenna and start watching. You may need a USB OTG cable to plug the tuner in your Android device. USB OTG cables are inexpensive and easy to find.
Note that your Android device must support USB OTG. If unsure, do a quick search online or consult your Android device manual. Also check that there is DVB-T/DVB-T2 service in your local area by doing a quick search online. Signal needs to be strong enough for Aerial TV to pick it up. For best results use an outdoor aerial.
You get free unlimited access to radio forever. You also get to watch all TV channels and experience all features of Aerial TV during the trial period for free. After the trial period ends you can make a one-off purchase and watch as much TV as you want. Remember: you can keep listening to radio even if the trial has ended!
Q: How do I find a supported dongle? A: All major RTL2832 (rtl-sdr) dongles are supported. These dongles can be easily purchased online. Just type in “RTL2832” or “RTL2832U” in the search box of your favourite online store.
Q: What tuner do I need to watch DVB-T2? A: If your country has DVB-T2 broadcasts (such as Freeview HD in UK) you will need a DVB-T2 compatible receiver dongle such as R828D in order to watch DVB-T2 with Aerial TV.
The new software requires a different DVB-T driver app to be installed first, which is also provided by Martin. This is because the RTL-SDR needs to be operated in a mode different to the way that the SDR drivers use it in. Martin has also open sourced his Android DVB-T driver and it is available on GitHub.
Aerial TV is currently free on the Google Play store, but looks like it may eventually have some in-app purchases. Also, it is currently marked as ‘Unreleased’ on Google Play, which is essentially a beta version, so you might expect there to be some bugs.
The SDRplay team have been hard at work during the last few weeks. First they announced beta support for Android via SDRtouch, then they announced an improved ADS-B decoder, and finally they have just announced their acquisition of Studio1.
The SDRplay is a 12-bit software defined radio with tuning range between 100kHz – 2 GHz. Many consider it along with the Airspy to be the next stage up from an RTL-SDR dongle.
The author of SDRTouch on Android recently announced support for the SDRplay. SDRTouch is a Android program similar in operation to PC based software like SDR#. To access the beta you can sign up at this link. Currently there is support for up to 2 MHz of bandwidth.
Recently the SDRplay team released an updated version of their ADS-B decoder for the Raspberry Pi which now fully utilizes the full 12-bits of the ADC and takes advantage of the full 8 MHz bandwidth. Jon, the head of marketing at SDRplay writes the following:
We now have an updated beta version of ADS-B for both the Raspberry Pi 2 and 3. This is based upon the 16bit Mutability version of dump1090 developed by Oliver Jowett and unlocks the full 12 bit performance of the RSP1. People should see a significant performance improvement over the dump1090_sdrplus version, which was based upon 8 bit code. The latest beta version can be downloaded in binary form from http://www.sdrplay.com/rpi_adsb.html . Should anyone have questions or feedback, please contact [email protected]
We plan to eventually compare the SDRplay with the Airspy and RTL-SDR on ADS-B performance. If you are interested we previously did a review of the SDRplay, Airspy and HackRF here, but as the SDRplay did not have ADS-B back then, that particular test was not done.
Acquisition of Studio1 SDR Software
The last major piece of news is that SDRplay have now acquired the Studio1 SDR software. Studio1 is a paid SDR program, similar in nature to SDR#/HDSDR/SDR-Console. Like HDSDR, Studio1 is a spinoff from the old WinRad software. Their press release reads:
SDRplay Limited has today announced that it has reached an agreement with Sandro Sfregola, (formerly CEO of SDR Applications S.a.s.) to acquire all Rights, Title and Interest in Studio 1 a leading software package for Software Defined Radio applications.
Jon Hudson, SDRplay Marketing Director said: “We are delighted to have reached this agreement with Sandro to acquire Studio 1. Studio 1 is the perfect complement to our SDR hardware products and gives us the ideal platform to deliver a complete class leading SDR solution for our customers. We look forward to working with Sandro and further developing Studio 1 to unlock the full capability of our current and future products”.
Hudson added: “Studio1 has established a strong customer base with users of many other SDR hardware products. Studio 1 will continue to be available as a stand-alone product from WoodBoxRadio http://www.woodboxradio.com/studio1.html for the foreseeable future , but we also look forward to further developing Studio 1 to specifically benefit present and future owners of our products”
Sandro Sfregola added: “I am very pleased to have reached this agreement with SDRplay. The long term future for SDR lies in complete end to end solutions and I feel the SDRplay RSP combined with Studio 1 software gives users an outstanding combination of performance and affordability”.
About Studio 1:
Studio1 was developed in Italy by SDR Applications S.a.s. and has hundreds of happy customers around the world.Studio 1 is known for its user friendly stylish GUI, CPU efficiency and advanced DSP capabilities, including features notavailable on other SDR software packages.
SDRplay limited is a UK company and consists of a small group of engineers with strong connections to the UK Wireless semiconductor industry. SDRplay announced its first product, the RSP1 in August 2014
We believe that this is a good move for SDRplay, as one of the major issues with the RSP SDR was the lack of decently supported software.
AISRec is an RTL-SDR compatible AIS decoder that is made for Windows and Android. AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system. We have a tutorial on this here (using other software).
The last time we tried AISRec we found that it had very good ability at decoding AIS messages, especially very weak ones and was by far the easiest AIS decoder to set up and use on Windows. The features include:
1. Work with all rtlsdr dongles. Allow future support for other SDR devices. 2. Stable reception of AIS signals at as low as SNR 7 dB. 3. Tolerance to frequency drifts > 30 ppm. 4. Dual-channel reception at 161.975 MHz and 162.025 MHz. 5. Channel selectivity > 56 dB. 6. Low CPU usage. No problem for Atom CPU and above. 7. Output all types of AIS messages (including Class A and Class B) in NMEA formats to UDP ports. 8. Convertion of AIVDM to AIVDO messages for your own ship. 9. Display of the received NMEA messages and the statistics.
The author of AISRec writes in an email to us an explains that the trial version has a time limit and an RX message count limit for each run, whereas the registered lite version will not. The pro version will have some additional features. Currently the author has no method for taking in paid registrations, but plans to have this ready in the future. We will post again once registration is available.
Previously we posted about Android programmer Tosis Nikolaos’s last app which was called “Track your flight Europe”. The app allows you to view aircraft tracked via ADS-B received by an RTL-SDR on an offline map.
Now Nikos has written into us once again to let us know about his new app called “Track your flight North America“. It is the same as his previous app, but this one has high resolution offline maps for North America. He also writes that his Europe app has also been updated to support high resolution offline maps. The app costs 5.09 Euros + VAT. To run it you will need an Android device and an RTL-SDR with OTG cable.
The post contains a full tutorial on the set up which involves the installation of ezstream and icecast for streaming audio as well as instructions for the installation of the modified version of rtl_fm called rtl_udp which allows remote control of the parameters via udp.