Thank you to Jacek / SQ5BPF for letting us know that he's recently released a modified version of the Telive TETRA decoder for Linux. The modification allows the user to listen to TEAx-encrypted voice signals if they have the decryption key. Typically, if a TETRA signal is encrypted, there is no way to listen to it, unless you have obtained the decryption key from the network operator, or extracted it from TETRA keyloader hardware.
But because the TEA1 encryption was broken due to a backdoor being discovered in 2023, he has also added support for using the 32-bit short key directly, which can be automatically recovered from TETRA traffic using his other software called teatime. TEA1 encryption is being phased out, but many deployments still use it.
The software is designed for advanced users to compile and run, so very little documentation is provided. However, there is a blog post here that explains the overall steps. Some additional information can be found on SQ 5BPF's RadioReference post here.
While not based on SDR technology, we think that some readers may be interested in this product.
We'd like to thank Serhii, who writes on behalf of SMLIGHT in Ukraine. SMLIGHT recently released its "SLZB-Ultima" device, a compact radio platform supporting multiple wireless technologies commonly used in smart homes.
These technologies include Zigbee, Thread, Wi-Fi, and Bluetooth. The device also optionally supports Z-Wave, LTE, Power-over-Ethernet, UPS backup, infrared control, and USB-over-Ethernet. The cloud-independent software supports WireGuard VPN, Dynamic DNS, Internal Zigbee hub mode, local IF-THEN automations running directly on the device, and one-click OTA updates.
Over on YouTube, RootKid, who specializes in creating engineering-based art projects, has developed an interesting wall-mounted art display panel that visualizes Wi-Fi activity by using a HackRF as the monitoring software-defined radio. The display uses a Raspberry Pi, a HackRF, and a custom-made LED light bar. The HackRF receives a 5 GHz Wi-Fi channel, and the Pi translates this into activity on the LED display, creating a visual piece that lets those around know when Wi-Fi activity is high.
The idea is to show that "we live surrounded by ghosts of our own making", which refers to the invisible storm of electromagnetic signals that we created to serve us in our modern lives.
Over on the YouTube channel "Nostalgia For Simplicity," the creator has uploaded a video where he revisits the original 1G analog cellular system, AMPS, to finally understand a mysterious phenomenon he experienced over 20 years ago as a kid, where he was able to unintentionally intercept other people's calls with his 1G phone. Using vintage hardware like the Ericsson DH668, he recreates a small AMPS network and confirms that the system is fully analog, instant, and surprisingly good-sounding.
AMPS worked by dividing the spectrum into numbered voice channels, with each call occupying one channel at a time. In busy cities, simply tuning to an active channel could let you hear someone else’s call. In this revival setup, there is only one active call, making the effect easy to demonstrate. This is essentially wideband analog FM voice on fixed channels, something easily observable and demodulated with modern SDR hardware.
Investigating this ancient 1G tech has highlighted why 1G systems were fundamentally insecure and why the world moved on to digital standards. If you're interested, the other videos on his channel continue to explore early cell phones and their quirks.
Over on GitHub we've recently seen a new open source program release called "web-spectrum". Web-spectrum is a multi-purpose browser-based tool. One interesting feature is that it allows you to view the GNSS spectrum (via a connected RTL-SDR or SDRplay with an appropriate antenna), decode it to a position, and also analyze the signal for jamming. It uses gnss-sdr or Gypsum as the backend GNSS processing tool.
The tool can also be used as a real-time spectrum analyzer, and for this, it supports RTL-SDR and SDRplay as well as the tinySDR Ultra spectrum analyzer.
Finally, in addition to GPS decoding, it also supports ADS-B and ISM band decoding.
Web-Spectrum: A Browser based tool for spectrum analyzer, GNSS analysis, and ADS-B and ISM band decoding.
Open.space is an upcoming open-source project aiming to unlock affordable earth-moon-earth (EME) bounce communications for the amateur radio public. To achieve this, they have designed a software-defined radio-based tiling system that allows people to easily create phased arrays.
EME (Earth–Moon–Earth) bouncing is a part of the amateur radio hobby that typically involves using (~1m - 3m diameter) high-gain dish antennas to transmit a signal toward the Moon, reflect it off the Moon’s surface, and have it received by a distant contact on Earth with similar hardware.
A phased array consists of a grid or lattice of many small antennas working together in sync. By applying tiny delays between elements and combining their signals, the array can make radio waves add up in one chosen direction and cancel in others. This lets software steer the receive/transmit beam electronically (no motors or moving parts), improving sensitivity and reducing interference. Compared to a dish antenna, it can scan and track targets much faster, form multiple beams if needed, and is compact and low-profile without physically turning. A common phased-array antenna many may have used before is a Starlink antenna.
A single open.space tile consists of a 4x4 MIMO SDR and four antennas. The SDR's frequency range covers 4.9 - 6.0 GHz, and it has 40 MHz of bandwidth via an 8-bit ADC. The tiles can be used on their own as a general SDR, for radio direction finding, as an Open-Wi-Fi router, as a 4G/5G basestation, or for drone HD links and robotics communications.
Multiple tiles can also be combined in a lattice shell to form the "Mini" starter phased array, which consists of 18 tiles. With the Mini phased array, you can achieve 60 degrees of beam steering, up to 34 dBi of gain, and 52.6 dBW of EIRP transmit power. The Mini is not large enough for EME, but upgrading to "Moon", which consists of 60 tiles, makes EME possible. "Moon" gets you 60 degrees of beam steering, up to 39.3 dBi gain, and 63.1 dBW transmit power.
This sounds expensive, but each tile is actually slated to cost only US$49-US$99. The Mini is priced at US$899 - US$1499, and the "Moon" at US$2,499 - US$4,999.
The Open.space hardware has not yet been released for sale, but the website indicates March 2026 as the expected shipping date. You can sign up to their email list on their website for updates.
Left: EME Concept, Middle: Single Tile, Right: Moon Phased Array consisting of 60 tiles.
ADSBee is an open-source project that has implemented a 1090 MHz ADS-B decoder on a Raspberry Pi RP2040 microcontroller using a programmable I/O (PIO) pin.
PIO pins cannot handle RF signals, so the ADSBee front end is a critical analog circuit that enables this to work. It consists of a 1090 MHz SAW filter to remove other signals, a low-noise amplifier, and, critically, a log-power detector, which essentially converts the pulse-position-modulated 1090 MHz ADS-B signal to baseband, which the PIO can handle.
However, this same trick does not work for 978 MHz UAT, as UAT signals are not pulse position modulation like ADS-B. Instead, for UAT support, the ADSBee design takes a more traditional approach, using a CC1312 sub-GHz transceiver chip connected to the RP2040.
Finally, an ESP32 S3 is added to the stack to enable networking via WiFi, allowing for received and decoded data to be used.
The project is entirely open source on their GitHub, apart from some of their commercial PCB designs. They also have a store, where they sell pre-made kits. A kit consisting of the ADSBee, 1090 MHz Antenna, and 978 MHz costs US$152in total. They are also selling an industrial model for $995, which includes PoE power.
Thank you to Andrew from Wavelet Lab, the original creators of uSDR and xMASS SDR, for writing in and sharing news about two of their soon-to-be-released SDR hardware products, xSDRand sSDR.
If you are unfamiliar with Wavelet Labs' previous products, uSDR is a small M.2 SDR board based on the Lime LMS6002D chip. It has both TX and RX capabilities, a 300 - 3700 MHz tuning range, and up to 28 MHz of bandwidth. xMASS, on the other hand, uses multiple modular 'xSDR' boards to create an up to 8x8 MIMO receiver. Previously, xSDR was only available for purchase with an xMASS board, but the new crowdfunding campaign makes xSDR available as a standalone product.
Andrew summarizes:
xSDR - a compact SDR module derived from the xMASS SDR (2 RX / 2 TX). We’ve seen many requests for the module itself, so we decided to make it available as a standalone product.
We add that xSDR has 2x2 MIMO RX/TX capabilities, an extended tuning range of 30 MHz to 3.8 GHz, and a channel bandwidth of up to 90 MHz. It retains the same M.2 connector and form factor as the uSDR.
sSDR - an M.2 form-factor SDR covering up to 11 GHz. This is our most ambitious bet so far, as there’s currently no comparable alternative on the market in this price range (~$1k).
sSDR has even higher rated specs, with 2x2 MIMO RX/TX capabilities, a tuning range of 30 MHz to 11 GHz, and a bandwidth of up to 120 MHz.
Andrew notes that xSDR is due to be released at the end of January, and sSDR in March.
