A call for participation in GRCon24, this year’s GNU Radio Conference, has opened – ahead of the event itself taking place this September – and interested parties have until the 17th of June to get their abstracts in.

“Packed with valuable content, the GRCon technical program is one of the best in the industry,” the event’s organisers boast. “With a great balance of cutting-edge research, new technology demonstrations, and shared insights from academia, industry, government, and the hobbyist community, GRCon is one of the best venues to learn and stay informed about the field of software radio. The GRCon program is recognized for its focus on practical design and implementation, and its content reflects the concept of ‘theory put into practice.'”

It’s with this in mind that the call for participation has gone out, looking for those interested in giving a 15 or 30 minute talk, 1-4 hour workshops, poster sessions, or breakout sessions. For those who want something a little snappier, lighting talks will also be available – though these, the event’s organisers explain, must be submitted in-person during the event itself.

For all other presentation or workshop types, and for those looking to submit a paper with or without a talk, the call for participation is open until the 17th of June 2024. “We invite developers and users from across the GNU Radio Community to present your projects, presentations, papers, posters, and problems at GNU Radio Conference 2024,” the organisers say.

More information on the event is available on the GNU Radio website, along with a link to submit an abstract for review.

A pair of researchers from Antalya Bilim University have penned a paper on delivering “wireless open source supremacy” with Osmocom-based indoor and outdoor networks for Internet of Things (IoT) workloads.

“In this work we focus on the use of the second generation of wireless technology (2G) for IoT applications, with more emphasis on the role of open source based architectures that can entirely shift the paradigm of connectivity,” Sadiq Iqbal and Jehad M. Hamamreh, of Antalya Bilim University’s WISLAB in the department of electrical and computer engineering. “More specifically, we explore the 2G-based open-source software called Osmocom and its potential to build IoT systems and applications.”

Describing Osmocom as having a “crucial role” in “enabling the transformation and convergence” of open-source telecommunications technologies, Iqbal and Hamamreh’s paper opens with a look at the history of cellular telecommunications and a primer on open source and the Internet of Things. The pair then look at Osmocom itself, including a look at building practical 2G cellular networks using the Osmocom software stack and a suitable software-defined radio.

“As we journey forward into this promising future, where open source, 2G technology, IoT, and Osmocom converge, a world of boundless opportunities unfolds,” the pair conclude. “It is a realm where connectivity knows no boundaries, and innovation thrives. This paper stands as a clarion call to all stakeholders in the telecommunications landscape to explore this uncharted territory. Together, we venture into a landscape of transformation, where Osmocom and open source are the keys to unlocking a world of possibilities.”

The full paper is available under open-access terms on ResearchGate.

Finnley Dolfin has bridged the old and the new with a project to link the Mastodon ActivityPub-based social network with classic POCSAG pager devices – delivering updates over the airwaves in textual snippet form.

“Driven by a mix of curiosity and nostalgia, I set out to link my pager – a relic from another era – with Mastodon, a modern node in the sprawling fediverse,” Finnley says of the project. “The goal? To pull down Mastodon notifications straight to my pager, blending the old-school reliability of pagers with the vibrant exchange of today’s social media.”

The pager in question is based on the Post Office Code Standardisation Advisory Group (POCSAG) standard, receiving 2FSK signals and decoding them to short text-only messages on dedicated devices designed to be clipped to the belt.

“This project isn’t just a technical marvel; it’s a homage to the enduring pager, proving that even in our smartphone-saturated world, there’s still room for the classics,” Finnley writes. “It underscores the potential of marrying legacy tech with digital platforms, creating a unique cross-time dialogue. At the heart of this project is the clever use of APIs from hampager.de and Mastodon, alongside SQLite3 for managing data and regular expressions to tidy up messages.”

The full project write-up is available on Finnley’s website, including the Python source code.

Ashish Derhgawen, meanwhile, is reaching even further back in radio’s history with a project to build a working radio transmitter from zinc oxide and “cat’s whiskers,” as brought to our attention by Hackaday.

“This has to be one of the most bizarre projects I have worked on. It is a transmitter that works without any transistors or tubes,” Ashish explains. “It utilizes a strange phenomenon known as quantum tunnelling. Quantum tunnelling is a phenomenon wherein a particle can disappear from one side of a barrier and reappear on the other side even if it doesn’t have sufficient energy to surmount the barrier. It seems as if the particle ‘tunnels through’ the barrier, hence the name. Quantum tunnelling is a consequence of the wave nature of matter. It is nothing less than magic.”

This “quantum tunnelling” transmitter is built from very simple materials: a zinc metal plate heated with a torch to create oxidised areas of negative resistance and a length of 30 AWG copper wire as the “cat’s whisker” connecting it to the rest of the circuit. “I’ve used a 4MHz crystal to set the frequency of the oscillator. The 10K pot is used to adjust the biasing,” Ashish adds. “The resistor and electrolytic capacitor on the keying circuit serve an important purpose. They smooth out the keying.”

While admitting that finding the sweet contact spot for the whisker is “a time-consuming task,” Ashish found the transmitter itself fully functional – until it was disturbed, moving the whisker off-position.

The full project write-up is available on Ashish’s website, with a supporting video on YouTube.

The Atlantic’s April 2024 issue includes a piece on the “radio squirrels,” a group of radio enthusiasts from California who are keeping the tradition of maritime Morse code alive – in stations which shut down in 1997.

“Nestled within the Point Reyes National Seashore, north of San Francisco, KPH Maritime Radio is the last operational Morse-code radio station in North America,” writes Saahil Desai for the publication. “The station – which consists of two buildings some 25 miles apart – once watched over the waters of the Pacific and Indian Oceans. Both KPH sites shut down in 1997, but a few years later, a couple of radio enthusiasts brought them back to life.

“The crew has gotten slightly larger over the years. Its members call themselves the ‘radio squirrels.’ Every Saturday, they beep out maritime news and weather reports, and receive any stray messages. Much of their communication is with the SS Jeremiah O’Brien, a World War II-era ship permanently parked at a San Francisco pier.”

The full article is available on The Atlantic’s website.

Pseudonymous electronics and communications engineer “IndiaRocketGirl” has published a video showing how it’s possible to receive weather satellite imagery using a homebrew Yagi antenna made from scrap measuring tape and plastic pipe.

“I’ve made two antennas,” IndiaRocketGirl explains, “one is four element and another is a three element Yagi antenna. I made [the four element Yagi] using metal measuring tape. The supporting structures for holding the tape were 3D-printed at my home. I have [also] made a support structure to hold the antenna – this makes handling the antenna easier.

“What are the things required? One, a metal measuring tape. Two, pliers for cutting the metal tape. Three, PVC pipes. Four, supporting structures to hold the measuring tape and the PVC pipe. Five, coaxial cable. Six, M4 screws and nuts.

“This four-element Yagi antenna is very directional,” IndiaRocketGirl notes, “and to receive signals from satellites you have to point the antenna towards the satellite and track it. The antenna is linearly polarised, so it can receive horizontally polarised or vertically polarised signals [depending on orientation]. The antenna performance [in testing] was excellent.”

IndiaRocketGirl has published a video showing how the antenna was designed and constructed on her YouTube channel, with a second video demonstrating its use to receive NOAA-19 weather satellite imagery.

YouTuber Gabe Emerson, meanwhile, is also building antennas out of scrap materials – in this case turning an old umbrella and an emergency foil blanket into a satellite dish.

“In a previous video I showed how you could make a working satellite dish from an umbrella covered in tin foil tape,” Gabe says by way of introduction to the video. “Now, I had a bunch of comments suggesting other ways I could do this, and improvements I could [make] or alternate ways to make a homemade satellite dish.”

This time around, while Gabe retains the umbrellas as the usefully dish-shaped base of the project, the foil tape is swapped out for a cheap emergency foil blanket. “I was surprised to find that the thermal blanket glued to an umbrella actually does work! I built this quickly and not very carefully,” Gabe adds, “so it could definitely be done a little better.

“The obvious drawback,” Gabe concludes, “is even the slightest gust of wind causes us to wiggle out of line and you’ve lost your signal – and in slightly stronger wind this [antenna] is in the next county.”

The full video is available on Gabe’s YouTube channel, saveitforparts.

Great Scott Gadgets has issued another progress report on the Universal Radio Test Instrument (URTI) project, which has now reached the stage of having physical board prototypes produced.

“We aim to develop an open-source SDR platform with an unparalleled set of radio investigation and experimentation functions in one versatile device,” Great Scott Gadgets’ Elizabeth Hendrex wrote of the project when it was announced last year. “URTI will offer radio amateurs, researchers, educators, and professionals an affordable, compact RF test tool that could be used in place of multiple expensive pieces of traditional radio test equipment.”

Since the project’s public inception, Great Scott Gadgets has been keeping up with its promise to issue frequent progress reports – the most recent of which completes phase two of the eight-phase plan, with the initial board design completed and produced in hardware for testing.

“During the hardware bring-up process we verified all power supplies, power switches, and clock signals,” Great Scott Gadgets’ Michael Ossmann writes in the latest status report. “We ported, installed, and tested the Saturn-V bootloader and Apollo debugger firmware. Additionally we developed gateware for the FPGA based on LUNA which allowed us to communicate with the FPGA over USB.

“Much of phase four, mainboard firmware and gateware development, was completed before and during mainboard hardware bring-up. Additional work will be required on gateware for the FPGA, especially DSP functions, control of the radio section, and applications. Some progress was made on phases three and five.”

The full status report is available on the URTI GitHub repository; initial prototypes are now being distributed to developers, the company has confirmed.

Finally, Hackaday has brought to our attention a project to automatically report its user’s location in less-populated areas – through the Automatic Packet Reporting System (APRS) on a High-Frequency (HF) band.

“For some time I’ve been intrigued with APRS over HF,” mononymous radio ham “Lonney” writes of the project. “While the VHF APRS system is very good, and easy to use with modern rigs like my Kenwood TH-D72A, you’re limited to being in range of an iGate or digipeater – normally not a problem in most populated places, and even many sparsely populated places [but] when I drove from Fairbanks Alaska to Seattle in May 2014, I ran VHF APRS with a 50W rig and decent antenna on the car, with a couple of exceptions (Tok AK and Whitehorse YT) once I was out of range of the digipeater in Fairbanks the coverage was non-existent until I was half way through British Columbia.”

Lonney’s solution: reporting location using APRS on HF, rather than VHF, bands. Using the JS8Call software running on a Raspberry Pi – later swapped out for a Dell Latitude laptop with car charger – Lonney found it working on the 80, 40, 30, and 20m bands. “40m seems to be the magic band for JS8Call,” Lonney suggests.

“The combination of enough stations running JS8Call at any given time, longer range NVIS during the daytime and the band opening up at night results in pretty much all position reports making it. And that’s only sending them once every 3 hours. In a mobile with a lower gain antenna, a bit more TX power and sending a position report every 10 minutes should result in a fairly good success rate?”

The full project write-up is available on Lonney’s website.