Lime Micro’s Andrew Back has demonstrated how the LMS8001 Companion Board, a programmable frequency-shifting add-on for software-defined radio boards, can expand the capabilities of the LimeSDR Mini and other SDR families to 10GHz and beyond, without the need for any special software or hardware modification.
“In this simple demo, we show how a LimeSDR Mini and LMS8001 Companion can together be used to observe signals up to 10GHz and beyond via general-purpose SDR software,” Andrew explains by way of introduction to the video demonstration.
“In this case, the GQRX software is capturing the down-converted 10.27GHz gunnplexer signal from the LimeSDR Mini. The LMS8001 Companion Board was configured via its GUI to generate the intermediate frequency fed into the LimeSDR Mini 2.0.”
The demo follows last month’s publication of documentation for the LMS8001 Companion Board here on MyriadRF and the release of formal test results for the device’s performance in the 3CM (10-10.5GHz) frequency band – a range outside the board’s official specifications, but nevertheless available to use with “excellent performance.”
The video demo is available on Crowd Supply and YouTube now. The LMS8001 Companion Board itself is available to order now via Crowd Supply at $399 with free global shipping; hardware ordered now is expected to ship in early December.
Developer Ciprian Mandache has released a software package which turns a low-cost Raspberry Pi Zero W single-board computer into a radio-frequency signal generator – no additional hardware required, beyond an optional external antenna.
“PIrateRF transforms your Raspberry Pi Zero W into a portable RF signal generator that spawns its own Wi-Fi hotspot,” Ciprian explains. “Control everything from FM broadcasts to digital modes through your browser – hack the airwaves from anywhere. [It features] 11 transmission modes including FM Station with RDS, Live Mic, FT8, RTTY, POCSAG pagers, Morse, SSTV, and Spectrum Paint. No internet needed, no external dependencies – just pure RF chaos in your pocket.
“PIrateRF wraps rpitx in a Go service that spawns its own Wi-Fi access point and serves a web interface. Boot up the [Raspberry] Pi, connect to its hotspot from any device (phone, laptop, tablet), open a browser, and you get a clean interface with all 11 transmission modes ready to go. Select your mode, configure your settings, upload your files if needed, and hit transmit. That’s it. No SSH. No command-line arguments. No file format confusion. The interface handles everything – automatic audio/image conversion, real-time transmission status, live output logs via WebSocket, and proper error messages.
“PIrateRF is designed for amateur radio experimentation and education – including safe indoor testing without external antennas,” Ciprian notes of the tool, which provides an extremely low-cost entry point for admittedly-limited software-defined radio transmission projects. “Built for engineers who understand that good RF practices matter more than arbitrary administrative boundaries. Users are responsible for compliance with all local RF regulations and licensing requirements.
“All demonstration images and testing in [the project’s] documentation were performed indoors without an antenna, with a maximum range of approximately 5 metres.”
A video demonstrating PIrateRF is available on YouTube; the software itself is available on GitHub under the permissive WTFPL public-domain licence. Additional information is available on the developer’s blog.
Turkish high-frequency integrated circuit maker Atek Midas is preparing to launch an open-source signal generator good up to 22.6GHz, featuring a claimed 1Hz tuning resolution: the DSG-22.6GHz.
“DSG-22.6 GHz is a high-performance RF source designed to meet the needs of modern test and measurement applications across a wide frequency spectrum,” Atek Midas’ Suleyman Yasin Dundar, Kağan Kaya, and Murat Aydin claim of the gadget. “This device delivers precision and flexibility in a highly portable package, covering a continuous range from 300MHz to 22.6GHz with 1Hz tuning resolution.
“Its signal generator has been engineered with excellent filtered and unfiltered characteristics, with a verified 40dBC harmonic level (up to 0dBm). With power output levels ranging from 15 dBm to -50 dBM, and its compact footprint it is handy whether in the field or at a bench.
“DSG-22.6GHz isn’t just any other piece of test equipment,” the trio claim of their creation. “It’s been thoughtfully engineered to be easy to use, with advanced features like support for a 10MHz external reference input via its built-in SMA port. It’s small enough to take anywhere, and can be powered by a USB Type-C power bank. A clear, friendly touchscreen interface means incremental adjustments are just a tap away.
“It also features firmware with convenient diagnostics, including temperature, voltage/current monitoring, and PLL lock status. These enhance reliability and simplify system integration. Whether you’re a researcher working with microwave equipment or a hobbyist digging deeper into SDR design, DSG-22.6GHz is an approachable tool worth adding to your arsenal.”
A pre-launch video demonstrating the device is available on YouTube, while interested parties can sign up to be notified when the project’s crowdfunding campaign goes live on Crowd Supply. Atek Midas has pledged to “share the schematics, firmware source files, and Python UI source files with everyone” at the end of the campaign, but at the time of writing had not committed to a particular licence.
A team of researchers at the University of California San Diego and the University of Maryland have demonstrated how a low-cost off-the-shelf software-defined radio can capture a surprising amount of unencrypted traffic relayed from satellites – including mobile phone calls, SMS text, in-flight Wi-Fi sessions, and even data from critical infrastructure providers, military, and government organisations.
“We pointed a commercial-off-the-shelf satellite dish at the sky and carried out the most comprehensive public study to date of geostationary satellite communication,” the team explains of its work. “A shockingly large amount of sensitive traffic is being broadcast unencrypted, including critical infrastructure, internal corporate and government communications, private citizens’ voice calls and SMS, and consumer Internet traffic from in-flight wifi and mobile networks.
“This data can be passively observed by anyone with a few hundred dollars of consumer-grade hardware. There are thousands of geostationary satellite transponders globally, and data from a single transponder may be visible from an area as large as 40% of the surface of the earth.
“We observed unencrypted cellular backhaul data sent from the core network of multiple telecom providers and destined for specific cell towers in remote areas. This traffic included unencrypted calls, SMS, end user Internet traffic, hardware IDs (e.g. IMSI), and cellular communication encryption keys. We observed unencrypted VoIP and internet traffic and encrypted internal communications from ships, unencrypted traffic for military systems with detailed tracking data for coastal vessel surveillance, and operations of a police force.
“We observed unprotected passenger Internet traffic destined for in-flight Wi-Fi users on airplanes. Visible traffic included passenger web browsing (DNS lookups and HTTPS traffic), encrypted pilot flight-information systems, and in-flight entertainment. Multiple VoIP providers were using unencrypted satellite backhaul, exposing unencrypted call audio and metadata from end users. Retail, financial, and banking companies all used unencrypted satellite communications for their internal networks. We observed unencrypted login credentials, corporate emails, inventory records, and ATM networking information. Power utility companies and oil and gas pipelines used GEO satellite links to support remotely operated SCADA infrastructure and power grid repair tickets.”
The team’s paper on the project, Don’t Look Up: There Are Sensitive Internal Links in the Clear on GEO Satellites, is available on the project homepage under open-access terms; it only includes, the researchers note, information on affected systems where mitigations have been deployed or a 90-day window for responsible disclosure has elapsed.
A team from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) has published a paper detailing mechanically-reconfigurable metamaterial antennas, dubbed “Meta-antennas,” which change their resonant frequencies as they shift in shape.
“We introduce Meta-antenna, a design and fabrication pipeline for creating frequency reconfigurable antennas while making use of a single type of mechanical metamaterial structure,” the team explains in the abstract to the paper. “Unlike traditional static antenna systems with fixed radiation patterns and frequency responses per geometry, Meta-antenna leverages mechanical reconfiguration to alter the radiation and geometry characteristics of the antenna, making it more versatile for sensing and communication.
“Meta-antenna provides a design space of resonance frequency from 500MHz to 6.3GHz (≥10dB) upon the structure’s compression, bending, or rotation. Additionally, we provide an Ansys-based editor that allows users to generate metamaterial antenna geometries and simulate their resonance frequency. We also provide a code template for Meta-antenna based sensing interactions.
“Our technical evaluation demonstrates that our fabricated Meta-antenna structures remain functional even after 10,000 compression cycles. Finally, we contribute three example applications showcasing Meta-antenna’s potential in adaptive personal devices, smart home systems, and tangible user interfaces.”
Those three demonstrations integrate the Meta-antenna systems into a curtain which automatically adjusts a smart lighting system, a set of headphones modified to switch between noise-cancelling and transparent operation modes when a Meta-antenna in the headband is expanded or contracted, and an “interactive tangible user interface” which acts as a physical flash card for learning Chinese characters.
A copy of the paper, presented at the 38th Annual ACM Symposium on User Interface Software and Technology (UIST ’25), is available under open-access terms on the project website; a supplemental video is available on YouTube.
Mobile developer Muhammad Atif Javed has released a tool which turns smartphones and tablets into real-time satellite trackers with augmented reality views: SpaceSight24.
“I’ve been building SpaceSight24, a mobile app that combines real-time satellite tracking with ham radio tools for operators and space enthusiasts,” Muhammad explains of the software. “It lets you: track the ISS, Starlink, and amateur satellites live; use [an] AR view to spot them directly in the sky; see azimuth, elevation, and pass timing for radio setups; get visibility and communication windows for active ham sats.”
The software, available for Apple’s iOS and Google’s Android mobile platforms, comes in “free” and “pro” variants. The former delivers tracking of “major satellites,” including the International Space Station, a constellation finder with five favourites, and a “basic” launch monitor, and is supported via in-app advertising; a $4.99 monthly or $39.99 annual subscription unlocks a full database of more than 12,000 satellites, unlimited favourites, and an advanced image viewer.
SpaceSight24 is available now on the Apple App Store and Google Play.
Embedded software developer and software-defined radio enthusiast Chris Gianakopoulos has released a library designed to provide automatic gain control, inspired by a 25-year-old paper by Fred Harris and Gregory Smith.
“An Automatic Gain Control (AGC) is a feedback system that adjusts the gain of a variable-gain amplifier (VGA) to maintain an operating point such as a voltage magnitude level, current magnitude level, or in the case of a digital radio, the magnitude of signal samples presented to the AGC,” Chris explains. “Typically, an average magnitude of a block of data is used to perform a smoothing action to the input provided to the AGC.
“My motivation for creating an AGC was to give people the ability to run SDR software on radios which contain A/D converters that produce eight-bit output samples. With a 48dB (theoretically, ignoring implementation loss), you don’t have much to work with in a radio environment with radically different signal strengths. With an amplifier, whose output drives an A/D converter, on the RTL-SDR, when I listened to aircraft frequencies, I would hear strong tones when a strong signal would be received. The solution was to reduce the LNA and mixer gains.
“I asked myself, why would I want to reduce front-end sensitivity when signal overload was not occurring at the variable gain amplifier input? It was A/D converter overload! With an AGC, the user can establish a safe operating point that allows enough headroom to avoid overload when a strong signal arrives. When the signal goes away, the gain is increased so that you can hear weak signals. I have worked so long with radios, that I have become biased towards radios having an AGC. You get lots of bang for the buck. It is my hope that some people, at the very least, look at my code. They might actually find it to be useful.”
The AGC itself is based on a 2000 paper by Fred Harris and Gregory Smith, On The Design, Implementation, and Performance of a Microprocessor Controlled AGC System for a Digital Receiver; full source code is available, along with a copy of the paper, on GitHub under the reciprocal GNU General Public Licence 3.
The UK government has opened a second consultation for changes to registration requirements for Personal Locator Beacon (PLB) devices, which it hopes will make it easier for HM Coastguard and other emergency services to respond to alerts.
“A package of updates has been drafted by the Maritime and Coastguard Agency (MCA) which includes bringing PLBs under regulations that already apply to Emergency Position Indicating Radio Beacons (EPIRBs),” an MCA spokesperson explains of the proposals. “The changes require people to register current and new PLBs with the MCA – online and free of charge – if they are carried on a UK flagged vessel, hovercraft or mechanically propelled watercraft, such as jet skis, wherever they may be.
“The proposals do not apply to PLBs on unpowered craft such as paddleboards, kayaks and canoes. However, the MCA encourages the registration of PLBs used in these instances. Registration means that when a PLB is activated, HM Coastguard can use the details supplied, such as emergency contacts, to gain crucial information to support rescue efforts and send the best resources to help. When PLBs and EPIRBs are registered, false alarms can be traced more efficiently, helping to avoid rescue teams being sent unnecessarily into potentially dangerous conditions.”
“Just 15 minutes spent registering a PLB online could make all the difference to being found and recovered safely from a life-threatening situation,” says Linda Goulding, UK Distress and Security Beacon Registry Manager, in support of the effort. “These proposals would require action by anyone using a current or new PLB on an applicable vessel, so we are consulting again for four weeks to make sure everyone gets a chance to have their say.”
Interested parties have until the 7th of November 2025 to respond to the consultation, with more information available on GOV.UK.
Finally, radio ham Ron Fitch has penned a letter in strong support of software-defined radio technologies – disagreeing with a claim by fellow ham Ira Wilner that SDRs have “ruined” the hobby.
“Ira Wilner completely misses the point,” Ron writes in his letter to Radio World. “Software Defined Radios haven’t necessarily ruined DX’ing, although they have certainly changed it in some circumstances.
“But let’s rewind 65 years ago – proponents of the AM method decried the use of single-sideband modulation as being the end of amateur radio. Not only has amateur radio survived, it has become more effective as a result, thanks in part to SSB. Wilner calls us lazy for not wanting to travel vast distances to operate a radio. I run radios remotely in Anza, Calif., (WA6TQT) and Ramona, Calif., (KN6NBT), saving me a 1,000-mile round-trip drive or Amtrak ride each weekend that I want to participate in radiosport contests using antenna farms I can only dream of in the San Francisco Bay area.
“As an avid pirate radio listener, the K3FEF WebSDR enables me to hear those stations – mostly low power on the east coast – that are not accessible on the left coast because we are still in daylight when many of those stations are operating. In California, we have been encountering a number of non-amateur beacons invading the 80/40 meter bands lately. SDRs like KFS and UTAH enable us to triangulate the directions these beacons are coming from. At 3327.4 kHz, just below CHU on 3330 kHz, there is a ‘DW’ beacon that has been running for years. Only using the KFS SDR am I able to even hear it; other stations around California and SDR radios are unable to hear it.
“In summary,: Fitch concludes, “DX’ing is about listening to stations distant from me, regardless of what kind of receiving apparatus is actually used to accomplish that goal. The fascination of DX’ing is here to stay, no matter how we go about it.”
The full letter is available on the Radio World website.