Version 1.6 of the popular Android based RTL-SDR software defined radio software, SDRTouch has been released. News comes via this forum post.
This release adds the following
They have also made the FFT engine about 3 – 4 times faster than in previous versions.
Download it from the Google Play store
Hackaday has brought to attention a tutorial written on the Raspberry Pi forums by Sonny_Jim showing how to decode pager transmissions on the Raspberry Pi. In the tutorial he also shows how to set up a web server to be able to view the decoded transmissions in a web browser.
He uses a RTL-SDR and Raspberry Pi and pipes the output of rtl_fm into the multimonNG software to decode the messages.
On the FUNcube Dongle blog/store amateur radio enthusiast DK80K (a.k.a Nils) has sent in a link to a 16 page pdf file showing a comprehensive tour on the FUNcube Dongle Pro+’s capabilities on the HF spectrum.
He gives an overview of many digital ham and HF utility modes including DRM, WSPR, RTTY, Olivia, MFSK16, PSK31, Pactor, Packet, Hellschreiben, ROS, SSTV, HF ACARS, SSB, CW, DSC/GMDSS, SITOR-A/B, Globe Wireless, Time Signals, ALE, Baudot, FAX and Stanag 4285.
The FUNcube is a software defined radio similar to the RTL-SDR, but with better sensitivity and noise performance, but at a higher price (around $200 USD). These modes can also be received with the RTL-SDR and an upconverter such as the Nooelec Ham-It-Up upconverter.
YouTube user Wolfgang Bleher shows in this video his reception and decoding of Morse code using an R820T RTL-SDR stick, HDSDR and CWSkimmer. He used a 2m Yagi as the antenna.
The Ham-It-Up upconverter uses a 5V USB power input. I discovered that different 5v power sources can cause significant interference with this upconverter, and the same effect will probably occur in other upconverters as well.
When the upconverter was powered by mains power via a phone charger, the signals were almost completely drowned out in noise. Powering it with a PC USB port was better, but the PC USB power introduced some other strong noise sources. Powering it with a battery (used a mobile phone with OTG cable) was the best option. There are still some strong noise sources present, but I can probably solve them with better shielding.
Click continue reading to see some comparison images.
Over on the Radio Antics blog fellow RTL-SDR enthusiast Andrew has been using the RTL-SDR to receive Slow Scan Television (SSTV) amateur signals. SSTV is a method ham radio enthusiasts use to send small images to one another. The images often contain their ham call sign overlaid on the image.
Andrew was able to receive several SSTV images using an R820T dongle tuned to the 27 MHz (11 meter) band. He also used a Funcube Dongle+ and got similar results.
Check out his post for some of the images he received, and his video below for an example of the receiving process.
Over on Reddit user olgierd has posted a video on this thread showing his work on developing a portable software defined radio based on an RTL-SDR R820T, the rtl_fm software and a Raspberry Pi with LCD screen. The software is based on rtl_fm which has the capability to demodulate FM/AM/SSB signals. His video shows him tuning to various signals using a tuning knob.
Note that his setup is capable of playing the audio, but it is not shown in the video as he only had earbuds connected. In the future he hopes to make it more portable by adding a li-ion battery.
Around the world meteorological weather balloons are launched twice daily, and continuously transit weather telemetry to a ground station using something called a radiosonde. The RTL-SDR software defined radio combined with a decoding program can be used to intercept this telemetry, and display it on your own computer. You will be able to see real time graphs and data of air temperature, humidity, pressure as well as the location and height of the balloon as it makes it's ascent.
Note that if you are in the USA, then this tutorial may not be applicable for you as different radiosondes are used. Instead have a look at this post which shows how to use the SkySonde software from NOAA. You can also try an alternative command line based decoder called RS available on GitHub.
This tutorial is also applicable to other software defined radios such as the Funcube dongle, Airspy, HackRF, BladeRF or even hardware radios with discriminator taps, but the RTL-SDR is the cheapest option that will work.
In this example YouTube user Superphish shows a radiosonde being received and decoded using a RTL-SDR, SDRSharp and SondeMonitor.
