Tech YouTuber Lon.TV has recently uploaded a video demonstrating how to identify and decode various digital transmissions with an RTL-SDR dongle. In the video he explains how to use VB Cable to pipe audio from SDR# into various decoders, and then goes on to show DMR, APRS, POCSAG, L-Band AERO, FT8, and JS8/JS8CALL all being decoded via an RTL-SDR Blog V3 dongle.
Paolo Romani (IZ1MLL) has recently released version 4.2 of his SDRSharp PDF Guide. The book is available for download on the Airspy downloads page, just scroll down to the title "SDR# Big Book in English".
As before the document is a detailed guide about how to use SDRSharp, which is the software provided by Airspy. While intended for Airspy devices, SDRSharp also supports a number of third party SDRs, including the RTL-SDR, and it is the software we recommend starting with when using an RTL-SDR.
Paolo writes:
My new v4.2 SDRsharp PDF is out. The guide is now 139 pages long, and covers all the settings, UI customization, included and third party plugins, and use of some external decoders and software, now with Spyserver integration with Raspberry Pi 3/4, etc etc...
DragonOS is a ready to use Ubuntu Linux image that comes preinstalled with multiple SDR software packages. The creator Aaron also runs a YouTube channel showing how to use the various packages installed.
In his latest video Aaron tests his Pi64 image with GR-GSM and IMSI Catcher running with the GNU Radio 3.10 platform on a Raspberry Pi 4. He tests operation with an RTL-SDR and LimeSDR.
GR-GSM is a GNU Radio based program capable of receiving and analyzing mobile GSM data. We note that it cannot decode actual messages without additional information about the encryption key, but it can be interesting to investigate the metadata. GSM is mostly outdated these days, but still used in some areas by some older phones and devices. IMSI Catcher is a script that will record all detected GSM 'IMSI' numbers received by the mobile tower which can be used to uniquely identify devices.
Short video setting up and testing GR-GSM on DragonOS Pi64 w/ GNU Radio 3.10 and the RTL-SDR. The current DragonOS Pi64 build has GNU Radio 3.8 and all the necessary tools to accomplish what's shown in this video. If you'd like to test the build shown in this video, it's temporarily available here until I finish and put it on Source Forge.
https://drive.google.com/drive/u/1/fo...
A LimeSDR and DragonOS Focal's Osmo-NITB-Scripts was used to create the GSM900 lab environment. The RTL-SDR was able to see and decode the GSM900 network and although only briefly shown in the video, the IMSI Catcher script works.
Here's the fork used for this video and for testing. There's also a pull request on the main GR-GSM repo for this code to be added.
Since 2021 we've posted about Viol Tailor's "uSDR" (microSDR) software a couple of times. uSDR is a lightweight general purpose multimode program for Windows that supports the RTL-SDR, Airspy, BladeRF, HackRF and LimeSDR radios. The software can be downloaded from SourceForce.
Viol notes that recently the project has been updated to V1.5.0 which brings the following new features and changes.
Thank you to Don for submitting news about the release of his new software titled "Skies-ADSB". Skies-ADSB is a browser based app that provides a 3D view of the air traffic around your area. The software can be served on a local networked Raspberry Pi, with ADS-B data being provided by an RTL-SDR connected to the Pi.
skies-adsb is a virtual plane spotting progressive web app (PWA) / virtual aquarium (with aircraft instead of fish) / interactive real-time simulation.
Aircraft are tracked via unfiltered ADS-B transponder data in real-time and rendered in 3D.
The ADS-B data source is meant to be a RTL-SDR receiver connected to a Raspberry Pi running on your home network.
Flight status data is provided by the FlightAware AeroAPI v2.
The aircraft photos are provided by Planespotters.net.
Thank you to Joseph IT9YBG for submitting his article describing how he has made an RTL-SDR based panadapter for his TECSUN PL660 portable shortwave radio. The post is a series of pictures that show how Joseph was able to open the PL660 and connect a coax cable to the IF output, and mount the connector on the plastic cover for easy access. He then connects that IF output to the RTL-SDR via a 10pF capacitor.
The result is that Joseph is able to receive the IF output of the PL660 at 451 kHz in SDRUno with his RTL-SDR Blog V3 running in Q-Branch direct sampling mode. He notes that although the IF bandwidth from the PL660 is small, it is possible to decode digital signals by passing the audio demodulated by SDRUno into decoding software.
Over on Twitter @dereksgc has been monitoring the 'Meridian' communications satellites, which are Russian owned and used for civilian and military purposes. The satellites are simple unsecure repeaters, meaning that actually anyone with the hardware can transmit to them, and have their signal automatically rebroadcast over a wide area. This has been taken advantage of recently by anti-Russian invasion war activists who have been trolling the satellite with SSTV images of the Ukrainian flag, as well as audio.
Apart from intentional abuse, a side effect of being an open repeater is that sometimes the satellite can pick up powerful terrestrial signals unintentionally, such as analogue broadcast TV from Turkmenistan. Over on his blog, @dereksgc has written up an excellent post documenting the background behind this finding, his entire setup involving the hardware he's using and how he's aligning with the satellite, and what software he is using to decode the TV signal. In his hardware setup he notes that he uses a HackRF, but that a RTL-SDR would suffice.
I've published a summary on how I received the analog TV broadcast via a Russian military satellite using an SDR, as well as the short story leading up to it.
— derek (@dereksgc) March 27, 2022
Check it out if you're interested!https://t.co/mgCScsDEgP pic.twitter.com/1Oeokg3MYB
Thank you to Ross for writing in and sharing with an articles that he's written about testing Tire Pressure Monitoring System (TPMS) sensors using an RTL-SDR and the rtl_433 decoder.
TPMS is a system installed on many modern cars (or retrofitted on older cars) that wirelessly monitors the tire pressure on vehicles in order to provide dashboard information that can improve safety and fuel economy. TPMS system typically transmit on license free bands, such as 315 MHz which can easily be received with an RTL-SDR.
Ross owns a 2008 Toyota Tacoma which has a built in TPMS system. Unfortunately he found that one of his sensors was broken as the TPMS warning light was consistently on, despite knowing that his tire pressure was correct.
Instead of purchasing an expensive TPMS diagnostic tool, Ross broke out his RTL-SDR and fired up rtl_433 which already contains a ready to use TPMS decoder. From the data received, Ross was able to determine that only three sensors were transmitting. Ross then goes on to use the RSSI signal power strength measurements provided by the rtl_433 output, while moving the antenna next to each wheel to determine exactly which wheel had the faulty sensor.
Ross's post goes into further details about his setup and the data he received from the sensors. He also created a follow up post, describing a bash script he wrote to automate the process.
