If you weren't aware KerberosSDR is our 4-channel phase coherent capable RTL-SDR unit that we previously crowdfunded back in 2018. With a 4-channel phase coherent RTL-SDR interesting applications like radio direction finding (RDF), passive radar and beam forming become possible. It can also be used as 4 separate RTL-SDRs for multichannel monitoring.
In previous posts we've shown some interesting experiments performed with the KerberosSDR. For example:
We note that V2 of our KerberosSDR demo software is also on the way but a little delayed. We are aiming to release a beta around the end of the year, or early next year at the latest. The new software will have better handling of bursty intermittent signals, and paves the way for new developments coming in 2021 such as combined passive radar direction finding.
The KerberosSDR: 4x Tuner Coherent Capable RTL-SDRKerberosSDR Android App for Direction FindingAn Example of KerberosSDR Passive Radar Display Peak Hold Displaying Aircraft and Road Tracks
A few days ago the developer of SDR# added a very useful AM Co-Channel canceller plugin, and just today he has also added a new FM Co-Channel canceller. A Co-Channel canceller allow a user to remove an interfering station, allowing a buried station to be received cleanly. This is especially useful for DXer's where strong local and weak distant overlapping stations are likely to be received at the same time. The plugin works with all SDR# compatible SDRs including the RTL-SDR.
On a related note, we wanted to point out that recently the Airspy website and downloads have been getting flagged by some antivirus software, however we believe these detections to be false positives caused by the very frequent update schedule of SDR#.
SDRSharp FM Co-Channel Canceller
Over on Twitter we've seen a couple of videos from @K7al_L3afta demonstrating how well the new FM Co-Channel canceller works.
NooElec have recently released for sale a GOES geostationary weather satellite reception bundle which includes a parabolic grid dish, feed, GOES LNA and RTL-SDR dongle. The bundle should be usable for the GK-2A satellite, as well as HRIT from polar orbiting satellites, although for HRIT those you'll need some way to motorize or hand track the satellites.
Typically to receive GOES a 2.4 GHz WiFi grid dish has been used in the past. While the mismatch between 2.4 GHz and the 1.7 GHz used by GOES doesn't cause too much trouble, the dish provided by NooElec has a feed optimized for the 1.7 GHz which should make receiving the signal easier. The bundle also comes with their SAWbird+ GOES LNA, one of their always ON bias tee E4000 tuner based RTL-SDR dongles and a roll of 10m LMR400 cable.
The bundle is currently available on Amazon USA priced at US$179.95. Canadian customers can also order from Amazon.ca for CDN$259.95. Amazon shipping is free within the USA, however shipping this overseas will cost at least US$100 extra due to the weight + additional import fees. That said, the coverage area of GOES is mostly only for the USA, Canada and South America.
If you're interested in GOES or GK-2A satellite reception we have a tutorial written here.
After a short break Frugal Radio's ongoing series of SDR beginners guide videos is back, and in the latest episode Rob provides part one of a two part overview of some software available to use with software defined radios such as the RTL-SDR.
In the video he demonstrates general Windows based receiver programs like SDR#, SDRUno, SDR-Console V3, HDSDR, as well as multiplatform software such as SDR Angel, GQRX and CubicSDR. He finishes up by explaining the options available for virtual audio cable programs, which are required to pipe audio from general receiver programs to decoders.
In the past we've posted about the QIRX software a few times as it is an RTL-SDR compatible program that has a focus on DAB+ decoding. However, recently QIRX author Clem wrote in to let us know about version 3 beta, which is now a multi-mode receiver supporting modes such as ADS-B, AM, NBFM, WFM, SSB as well as DAB+ as it did in previous versions. It also now support ADS-B plane mapping, and can run multiple RTL-SDRs at once. We note that this version is not yet available for public download, however you can get the beta by contacting the author (details below). Clem writes:
In short, there are two main new features:
Multi-Receiver: More than one hardware RX can be connected, all I/Q data are fed via TCP/IP, local or remote. The configuration is read from the config file, per default prepared for three receivers.
As before, TCP/IP drivers for RTL-SDR dongles, the RSPs (RSPDuo single-channel), and Airspy. All binaries are part of the installer.
Although the software is "general purpose", particular emphasis has been given to serve aviation enthusiasts.
ADS-B: Aircrafts are displayed on the map. Information for about 450.000 aircrafts comes from an open database kindly provided by Opensky-network.org, updateable by the user from within the software, similar like the DAB database. The ADS-B decoder is a C# port of the well-known dump1090 software, with enhancements to decode aircraft ground movements.
The displayed aircrafts are those within the range of the attached receiver. In contrast to some other applications, it might be noted that the software is capable to decode the movements of the aircrafts not only when airborne, but also on the ground, of course when in range. This might be interesting for plane spotters, perhaps in the vicinity of an airport.
The AM decoder provides special features when tuned to the airband range and - as should be standard nowadays - 8.33kHz channel separation has been selected. In contrast to older times, in airband communications no longer frequencies in MHz are communicated, but channels. The software (in live mode, not visible in the above picture taken from a file replay) provides an own airband channel selector, directly accepting channel numbers as spoken by ATC controllers. This is paired with the indication of channels in the spectrum, together with the corresponding frequency. With 8.33kHz channel separation, cheap dongles should be calibrated to receive the correct frequency, e.g. with QIRX's DAB decoder (where DAB is available).
Readers interested to give this version a try might send an email to [email protected] and they will receive the current beta version (Win10 .msi installer). As it might not yet have its final stability, it is not yet provided for download. Of course all beta users are requested to give some feedback.
QIRX V3 ADS-B Interface: Showing activity over Zurich Airport
Clem has also provided a YouTube video demonstration 20 minutes of ADS-B and airband voice activity over Zurich airport via the new multi-receiver and ADS-B mapping features in QIRX.
Over on Kickstarter we've recently come across a project called "WeatherSense" which is currently being crowdfunded. WeatherSense is a custom built set of 433 MHz wireless weather sensors made for makers. The outdoor "WeatherRack2" unit includes sensors and features like an anemometer, sunlight sensor, rain gauge, UV sensor, temperature and humidity sensor. wind direction sensor, as well as a solar panel for battery life extension and a Stevenson screen for shielding. They also have indoor units that measure temperature and humidity.
What's interesting to us is that they are using an RTL-SDR + Raspberry Pi as part of their 433 MHz receiver system. Their system includes a Raspberry Pi SD card image with built in Python software that is used with the RTL-SDR for receiving and decoding the weather sensor signals. They also provide an option for a simpler Arduino + 433 MHz receiver kit if you didn't want to use an SDR.
The campaign is currently fully funded, with 6 days left in the campaign. A kit including RTL-SDR and WeatherRack2 currently costs US$126 + shipping.
The Weather Sense WeatherRack2WeatherSense 433 MHz Weather Sensors. Using RTL-SDR for the receiver.
DragonOS is a ready to use Ubuntu Linux image that comes preinstalled with multiple SDR program. DragonOS-Focal (the build with the latest updates) has recently been updated to include the latest version of an interesting program called QRadioLink. We've posted about QRadioLink a few times in the past, but if you haven't heard about QRadioLink before this is the description from the website:
QRadioLink is a GNU/Linux multimode SDR (software defined radio) transceiver application using the Internet for VOIP communication (radio over IP), built on top of GNU radio, which allows experimenting with software defined radio hardware using different digital and analog radio signals and a Qt5 user interface.
Its primary purpose is educational (demonstrating radio communications to children at schools), but it can also be customized for low power data communications on various ISM frequency bands. It can also be used as an amateur radio SDR transceiver for experimentation.
The latest DragonOS YouTube video author Aaron demonstrates the use of the QRadioLink Radio over IP feature, when combined with an RTL-SDR and umurmur server. Umurmur is a minimalistic mumble server, which is a Voice over IP (VoIP) application. Aaron runs the RTL-SDR and mumble server on a remote LattePanda single board computer, which then broadcasts music received via the RTL-SDR over a VoIP internet link to a laptop.
DragonOS Focal QRadioLink Radio over IP w/ RTLSDR (GNU Radio, umurmur, lattepanda)
