A few days ago we posted about how Domi aka Domonkos Tomcsányi wrote on his blog about decoding and decrypting GSM signals from your own cell phones. Domi also did a talk at the CampZero conference which has now been uploaded to YouTube. His slides can be obtained from this link.
Marc Higginson-Rollins of the University of Kentucky has published an academic styled paper in conjuction with Dr. Alan E.E. Rogers of the MIT Haystack Observatory showing how they used an RTL-SDR to implement a Small Radio Telescope (SRT).
In the paper they discuss how they dealt with the frequency drifting and offset problems common in the RTL-SDR. They also show how they dealt with the center spur by correcting the bias that it introduced and how they filtered out RFI noise from a nearby radar station and electronics.
Using the RTL-SDR and SRT they were able to measure the spectra of several well known regions of neutral hydrogen emissions, and measure the galactic rotation curve shown below.
Wavesink Plus, the paid version of the trial version of Wavesink has been released on Google Play. Wavesink Plus is an Android app which has FM+RDS, DAB+ and DRM+ receiving and decoding capabilities when connected to an RTL-SDR dongle via a USB OTG cable.
We gave Wavesink Plus a test today on a HTC One X Android phone and were pleased to discover that it works perfectly. The user interface has been tidied up from previous versions, and DAB+ has been added. There is now also auto tuning functionality, which will automatically find a station.
In further testing we found that the latest version of Wavesink was fast and snappy and was able to load DAB+ stations quickly, and decode them with clear audio. FM radio also sounded clear and RDS information loaded quickly as well.
Download the trial version here and buy the full version from this link.
Rishi Patel has written on his blog about his radio astronomy project which involves an RTL-SDR and an impressive homemade horn antenna.
The horn antenna is constructed from cardboard foam and aluminium foil and is mounted on a telescopic mount. The horn then connects to a waveguide feed which is constructed out of a large metal can. The antennas waveguide then connects to a microstrip filter and LNA before finally connecting to an RTL-SDR. Rishi then uses a simple python program to gather the IQ samples from the RTL-SDR, and then draw the power spectral density plots.
With this setup Rishi was able to detect the Hydrogen line. Rishi also used a second even larger horn with a different design to plot the spectrum shown below of the Cygnus (red), Cassiopeia (green), and Cepheus (blue) constellations.
A while back we did a small write up on receiving and analyzing cellular GSM signals with the RTL-SDR. Now blogger Domi has taken it further and has done an excellent big write up on his blog showing how to receive, decode, and also decrypt your own cell phone GSM signals with the RTL-SDR.
Domi’s big write up is split into four posts. It starts with an introduction to GSM, then focuses on setting up the environment and required software, then uncovering the TMSI (step to be released later), and then finally shows how to actually receive and decrypt your cell phone data such as voice and SMS messages.
Amateur radio hobbyist EB3FRN has made a post on his blog showing how he was able to use an RTL-SDR to act as a passive radar and detect meteors from the Perseids meteor shower. To do this he tuned to 143.050 MHz which is the the frequency of the Graves radar, a French space surveillance radar used to spot satellites and detect their orbits. He then used the Baudline software to record the radar signal scatters which occur when a meteor reflects the Graves radar signal.
The programmer of the Android based software defined radio app SDR Touch has released a public beta of version 1.7. The programmer writes that the new features include
New multi-threaded core, native audio support, experimental x86 support is included as well. Although most changes are under the hood (the release is build for performance boosts), probably the most obvious non-performance enhancement is FM STEREO.
If you intend to install the beta you will need to first uninstall your existing version of SDR Touch, which will cause you to loose any presets you may have set. The programmer warns that this version may be unstable as it is in beta.
You can download the beta from http://sdr.martinmarinov.info/
Akos from the SDR for mariners blog has just written another post that is a guide on constructing and buying beginner level antennas for the RTL-SDR. The post shows how to build a simple ground plane antenna out of wire coat hangers, and also discusses monopoles, telescopic antennas, rubber duckys and discone antennas.
