Could Reticulum Power A Post-Internet Network?

July 20, 2026 by Tyler August 29 Comments

These days, it is easy to think you always have access to the Internet. But some wonder if — in spite of its ARPANET, nuclear-war-planning heritage — you can actually count on it to be there when things go pear-shaped. [The Tech Prepper], as you might imagine, is quite concerned with that last question, and is flogging Reticulum over high-frequency radio as a post-internet network in a video embedded below.

Reticulum is a cryptographic network stack, fully decentralized and amazing from a cyberpunk/hacker/survivalist perspective. Unfortunately for [The Tech Prepper], until the you-know-what hits the ventilation unit and the FCC and its counterparts in other countries are too busy to be concerned with such trifles, encrypted signals are banned on ham radio bands just about everywhere. That’s why his demo is using a dummy load on the Mercury HF modem instead of an antenna: the feds don’t care if the signal doesn’t leave the building. The video shows how to replicate the setup using his EmComm Tools suite on Ubuntu.

Perhaps more interesting is his vision of a Post-Internet network, be it in a disaster scenario, as he envisions, or simply because we get sick of what the internet has become. The idea of easily hooking an open-source radio modem to a PC running modem73, open-source SDR software, has a certain appeal. Reticulum isn’t your only option there: modem73 will let you run a BBS in the clear — that is, unencrypted and legal to transmit — and let’s face it, wasn’t life online more fun in BBS days?

This isn’t the first time we’ve seen the Reticulum network stack, but last time it was operating at considerably shorter ranges over LoRA.

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Your AI Ham Radio Buddy

July 18, 2026 by Al Williams 12 Comments

AI chatbots are everywhere these days, and they seem to “know” about everything. But while that is a strength, it can sometimes be a weakness because it isn’t laser-focused on one topic. Not so with this Ham-radio-centric chatbot called HamGPT. The service is clearly built on another GPT engine but understands how to retrieve data from common ham radio sources, such as the FCC database, propagation reports, and the like. It didn’t, however, seem to have access to ham radio-related books, magazine articles, or other “static” data that we could tell.

You do have to sign up for an account, which includes providing your callsign and location. There is a free tier that allows a limited number of queries per day, so you can try it to see if it is useful for you without subscribing.

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Transponder Mania

July 16, 2026 by Fenix Guthrie 28 Comments

In order to not hit something, you generally need to know where that thing is. On land, the meager human eyesight tends to be sufficient. On the water, however, the prospects are more dangerous and complicated. So, technology is required to ensure safe ocean voyages in the form of the AIS transponder system. The off the shelf solutions tend to work quite well, but [peterantypas] was displeased with the commercial offerings, and built what appears to be the first open source AIS transponder called MAIANA.

Automatic Identification System (AIS) is a GPS tracking system designed for maritime applications. Broadly speaking, it broadcasts GPS and other data at intervals over VHF radio. AIS is what allows the precise tracking of vessels by authorities, and online hobbyists. AIS is also often received by other vessels to augment radar improving boat to boat collision safety.

Most commercial AIS transponders used by sailors are rather bulky, expensive, come with a large power budget. The MAIANA project avoids these pitfalls by being entirely self-contained. The RF portion is largely made up of a STM32L4 micro controller, a SI Labs Si4460 ISM RF chip, and a Quectel L76L-M33 with a Johansson ceramic chip antenna for GPS. With such simple hardware, the PCB is easily small enough to fit inside the antenna assembly.

This design eliminates the need for long runs of multiple shielded RF cables to a bulky transponder unit inside. Instead, a simple Ethernet cable is used to transfer data to and from the mast. Inside the boat, a USB decoder is used to pass the AIS data on to a PC. This whole setup is remarkably simple and reliable, with hundreds of units having been produced since the project’s start.

While this is the first full blown AIS transponder we have covered, we have seen other projects utilizing the protocol. We have also seen quite a number of projects with the aircraft equivalent, ADS-B.

Thanks [Bernerd] for the tip!

DIY SI5351 Radio Tunes In SW, MW, And More

July 2, 2026 by Zoe Skyforest 12 Comments

There are plenty of radios you can buy that pick up MW and SW bands if that’s what you’re into. Or, you can follow [mircemk]’s example, and whip one up yourself instead.

The build employs an ESP32 as the brains of the operation. It’s hooked up to a rotary encoder and a small colour TFT screen, which displays an old-school style tuning dial for choosing the desired frequency. This setup is paired with an Si5351—a capable clock generator chip that can deliver just about any frequency from <8KHz up to 150+ MHz on command. There’s naturally a bunch of supporting analog hardware for the radio end of things, plus a NE612 mixer IC and a PAM8403 class D audio amplifier board, hooked up to a small 0.25W speaker for audio output. [mircemk] has set up the rig to act as a simple radio set, or, with the flick of a switch, it can be configured for SDR use with an attached computer.

It’s a handsome build, and one that likely proves a pleasant way to browse the MW and SW bands on a rainy afternoon. We’ve looked at other hardware in this category before, too. Video after the break.

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Positioning Without Satellites Or Base Stations

July 1, 2026 by Jenny List 37 Comments

We’re all used to satellite navigation systems such as GPS or GLONASS, sheer magic in which the combination of a set of reference transmitters and super-accurate timing information can be used to calculate a position to an astounding precision. They had land based predecessors such as LORAN and Decca Navigator which worked in a similar fashion but with fixed land-based reference transmitters. Terra is an attempt to do the same thing without a network of dedicated transmitters, instead using FM broadcast transmitters as its fixed points.

This might seem like an impossible task without access to the transmitters, but they have a workaround using the Internet as a backhaul. Instead of transmitting their timing information like the systems mentioned above, they rely on a set of reference receivers sharing it online to the client’s receiver software. So far they have a demo running in Denver.

The interesting thing about this system is that it’s open-source, and requires only a relatively inexpensive software defined radio receiver and a computer to operate. Now anyone with a group of internet-connected friends to set up reference receivers can have their own positioning system, it’s no longer the exclusive preserve of governments. We like this idea, and we look forward to seeing it being tested more widely.

If you’d like to know where we’ve come from, we’ve taken a look at LORAN before.

RF Hacking A Ceiling Fan Via The Remote

June 28, 2026 by Zoe Skyforest 16 Comments

[Sam Wilkinson] recently installed a Dreo CLF513S ceiling fan in his place — it’s cheap, well-sized, and blows air around as you’d expect it to. The only problem is that it only works with an ugly cloud-only smart home setup out of the box. Never mind, though, because [Sam] figured out how to hack up a custom solution.

Hacking efforts began with the included remote control. [Sam] identified that the remote had to be RF, since it didn’t need line of sight to work properly. The FCC ID on the back of the device further indicated this was the case. Armed with that knowledge, it was simply a case of figuring out the commands sent by the remote, building something to replay them, and then hooking that into [Sam]’s existing Home Assistant setup.

The remote ran on 433.92 MHz, a not-uncommon bit of spectrum for these sort of appliances. An RTL-SDR was thusly enlisted to capture the output, with a spectrogram indicating the remote used simple on-off keying to send commands. Once commands were captured, [Sam] grabbed an ESP32-C6 microcontroller, hooked it up to a RFM69HCW radio transceiver, and programmed it to replay the fan on/off command. From there, a little dabbling with MQTT got the ESP32 controlling the fan as desired from within the Home Assistant ecosystem.

Sometimes, it’s hard to find smart home gear that actually suits your tastes and budgets. Often, a bit of tinkering can shape existing appliances to bend to your will instead. If you’re tweaking your own gear to better fit your smart home, don’t hesitate to notify the tipsline.

Requiem For Long Wave, As The BBC Goes Silent

June 27, 2026 by Jenny List 61 Comments

Something happened this morning which will have been unnoticed by many, but which for a certain breed of radio enthusiast marks the end of an era. The BBC stopped broadcasting Radio 4 on their 198 kHz Long Wave frequency, ending over a century of transmission in the band. For now the transmitter carries a recorded message telling listeners that the service has ended, but it’s expected that this will soon be turned off.

A pair of very large transmitting masts against a cloudy grey sky. — The main 198kHz BBC transmitter, at Droitwich. Bob Nienhuis, Public domain.

American readers may be unfamiliar with Long Wave as it’s a band not allocated in their region. Covering 153 to 279 kHz, it’s a relic from the earliest days of high-power broadcasting in the 1920s, used because of the enormous distances that could be covered with its lower frequencies. The main long wave transmitter for the BBC is at Droitwich, and its demise comes because there are no more spares for its high-power transmitter tubes. It joins many Medium Wave, or AM, as it is commonly known, stations in leaving the airwaves, as increased interference from switch mode electronics and the availability of higher quality alternatives took away their listeners. It’s fair to say that there will be few whose lives are inconvenienced by the switch-off in 2026, but it’s worth taking a moment to remember.

The first BBC Long Wave transmissions in the mid-1920s were on a 1600 metre wavelength, or 187.5 kHz. A series of international agreements saw them move to 193 kHz, and then 200 KHz or 1500 metres in 1934. They stayed on that frequency until another shift down 2 KHz to 198 kHz in 1988. They were atomic-controlled, and thus usable as a frequency standard. The programming started with station names redolent of their era, first the BBC National Service, then the Light Programme you’ll see on the dial in the header image, and finally the more modern-sounding Radio 4. A famous BBC programme tied to Long Wave is the Shipping Forecast, a weather bulletin for deep-sea fishermen which became cult listening on land and now features on FM and digital services too, and there’s even a probably-apocryphal tale that British nuclear submarine captains would once use its presence or absence to judge whether nuclear war had occurred.

In an Oxfordshire farmhouse not far short of fifty years ago, a young child who would later become a Hackaday writer heard a radio show like nothing before, which made an impression that continues to this day. The show was one of the earliest airings of the original Hitchhikers Guide To The Galaxy radio series, through a 1970s ITT radio tuned to BBC Radio 4 on (then) 200 kHz Long Wave. So long, Droitwich, and thanks for all the fish.