We’ve been going on at length in this space about the death spiral that AM radio seems to be in, particularly in the automotive setting. Car makers have begun the process of phasing AM out of their infotainment systems, ostensibly due to its essential incompatibility with the electronics in newer vehicles, especially EVs. That argument always seemed a little specious to us, since the US has an entire bureaucracy dedicated to making sure everyone works and plays well with each other on the electromagnetic spectrum. The effort to drop AM resulted in pushback from US lawmakers, who threatened legislation to ensure every vehicle has the ability to receive AM broadcasts, on the grounds of its utility in a crisis and that we’ve spent billions ensuring that 80% of the population is within range of an AM station.

The pendulum has now swung back, with a group of tech boosters claiming that an AM mandate would be bad, forcing car manufacturers to “scrap advanced safety features” like “advanced driver-assistance systems, autonomous vehicles, and collision avoidance systems that actually reduce car accidents and fatalities.” That last part is a bit of a reach considering recent research (second item) showing the iffy efficacy of some of these safety features, but the really rich part is when the claim that continuing to support the “outdated technology” of AM radio would prevent engineers from developing “future safety innovations.” Veiled threat much? And pretty disrespectful to the engineering field in general, we have to say, given that at its best, engineering is all about working within constrained environments and supporting conflicting goals.

While most of America was celebrating the Independence Day holiday last week with raucous pyrotechnic displays, one town in Washington State was enjoying a spectacle of a different sort: watching a swarm of drones commit mutual suicide. For various reasons, the city of SeaTac decided to eschew the more traditional patriotic display and plunk down $40,000 on a synchronized aerial drone show, which despite the substitution of chest-thumping explosions with the malignant hornets-nest buzz of 200 drones actually looks pretty cool. Right up until 55 of the drones went rogue, that is, and descended toward the watery doom of Angle Lake below. It wasn’t clear at first what was going on; video of the incident shows most of the drones gently settling into the lake, with only one seeming to just crash outright. That pretty much lines up with the official line from Great Lakes Drone, the outfit running the drone show, who blamed “outside interference” for the malfunction. A costly malfunction, by the way; at $2,600 a copy, the 55 drowned drones total nearly $100,000 more than the contracted price for the show. Forty-eight of the lost drones have been recovered, which points to perhaps the one bright spot of the story — the local diving club probably got a lot of bottom time thanks to the recovery effort.

Ten months is a long time in the rapidly changing technology world, but to go from expensive IoT doodad to brick in less than a year has to be some kind of record. And in a strange twist, it’s actually not Google this time, but rather Amazon, who just announced that their Astro for Business robots will cease to function as of September 25. The device, which is basically a mobile Alexa, was initially targeted at consumers who wanted something to roll around inside their homes to collect data for Amazon monitor security and keep an eye on your pets. Last November, Amazon announced an Astro for Business version that did much the same for the small and medium business market. Amazon seems to have made the decision to unfork the market and concentrate on the home version, which seems to make more sense. Business owners will get a refund on their bricked devices and a $300 Amazon credit for their troubles, but there’s no word on what will happen to the devices. Here’s hoping some of them show up in the secondary market; we’d love to see some teardowns.

And finally, if you think there’s nothing interesting about a big steel box, you’re either reading the wrong website or you haven’t seen the latest video by The History Guy on the history of the humble shipping container. We’ve always been a bit of a shipping container freak, and we’ve long known that the whole idea of containerized cargo reaches back to the 1950s or so. That’s where we thought the story started, but boy were we wrong. The real story goes back much further than that, all the way to the “lift vans” of the early 20th century, which were wooden boxes that could be hoisted from a wagon onto a ship and move a lot of items all in one go. We also had no idea where the term “ConEx” came from in reference to shipping containers, but THG took care of that too. Fascinating stuff.

When we first spotted the article about a one-transistor amateur radio transceiver, we were sure it was a misprint. We’ve seen a lot of simple low-power receivers using a single transistor, and a fair number of one-transistor transmitters. But both in one package with only a single active component? Curiosity piqued.

It turns out that [Ciprian Popica (YO6DXE)]’s design is exactly what it says on the label, and it’s pretty cool to boot. The design is an improvement on a one-transistor transceiver called “El Pititico” and is very petite indeed. The BOM has only about fifteen parts including a 2N2222 used as a crystal-controlled oscillator for both the transmitter and the direct-conversion receiver, along with a handful of passives and a coupe of hand-wound toroidal inductors. There’s no on-board audio section, so you’ll have to provide an external amplifier to hear the signals; some might say this is cheating a bit from the “one transistor” thing, but we’ll allow it. Oh, and there’s a catch — you have to learn Morse code, since this is a CW-only transmitter.

As for construction, [Ciprian] provides a nice PCB  layout, but the video below seems to show a more traditional “ugly style” build, which we always appreciate. The board lives in a wooden box small enough to get lost in a pocket. The transceiver draws about 1.5 mA while receiving and puts out a fairly powerful 500 mW signal, which is fairly high in the QRP world. [Ciprian] reports having milked a full watt out of it with some modifications, but that kind of pushes the transistor into Magic Smoke territory. The signal is a bit chirpy, too, but not too bad.

We love minimalist builds like these; they always have us sizing up our junk bin and wishing we were better stocked on crystals and toroids. It might be good to actually buckle down and learn Morse too.

It’s said that “Golf is a good walk spoiled,” so is attaching an amateur radio to a bike a formula for spoiling a nice ride?

Not according to [Wesley Pidhaychuk (VA5MUD)], a Canadian ham who tricked out his bike with a transceiver and all the accessories needed to work the HF bands while peddling along. The radio is a Yaesu FT-891, a workhorse mobile rig covering everything from the 160-meter band to 6 meters. [Wes] used some specialized brackets to mount the radio’s remote control head to the handlebars, along with an iPad for logging and a phone holder for streaming. The radio plus a LiFePO₄ battery live in a bag on the parcel rack in back. The antenna is a Ham Stick mounted to a mirror bracket attached to the parcel rack; we’d have thought the relatively small bike frame would make a poor counterpoise for the antenna, but it seems to work fine — well enough for [Wes] to work some pretty long contacts while pedaling around Saskatoon, including hams in California and Iowa.

The prize contact, though, was with [WA7FLY], another mobile operator whose ride is even more unique: a 737 flying over Yuma, Arizona. We always knew commercial jets have HF rigs, but it never occurred to us that a pilot who’s also a ham might while away the autopilot hours working the bands from 30,000 feet. It makes sense, though; after all, if truckers do it, why not pilots?

Begun, the Spectrum Wars have. First, it was AM radio getting the shaft (last item) and being yanked out of cars for the supposed impossibility of peaceful coexistence with rolling broadband EMI generators EVs. That battle has gone back and forth for the last year or two here in the US, with lawmakers even getting involved at one point (first item) by threatening legislation to make terrestrial AM radio available in every car sold. We’re honestly not sure where it stands now in the US, but now the Swiss seem to be entering the fray a little up the dial by turning off all their analog FM broadcasts at the end of the year. This doesn’t seem to be related to interference — after all, no static at all — but more from the standpoint of reclaiming spectrum that’s no longer turning a profit. There are apparently very few analog FM receivers in use in Switzerland anymore, with everyone having switched to DAB+ or streaming to get their music fix, and keeping FM transmitters on the air isn’t cheap, so the numbers are just stacked against the analog stations. It’s hard to say if this is a portent of things to come in other parts of the world, but it certainly doesn’t bode well for the overall health of terrestrial broadcasting. “First they came for AM radio, and I did nothing because I’m not old enough to listen to AM radio. But then they came for analog FM radio, and when I lost my album-oriented classic rock station, I realized that I’m actually old enough for AM.”

Have you or a loved one been injured by falling space debris? You may be entitled to significant compensation. Call 1-800-SPACEJUNK for a free consultation with one of our attorney specialists. OK, maybe it hasn’t gotten to that point yet, but when SpaceX has set up a space debris hotline, you know the lawsuits are just around the corner. The move seems to be related to a piece of junk that fell on a campground in North Carolina earlier in the year which was identified as a section of a SpaceX Dragon that had brought astronauts to the ISS. The rather furry-looking piece of debris has apparently remained on the campground and is even being used to attract business, which seems a far better outcome than the Florida family whose roof caught a chunk of an ISS battery pack. No word on what happens if you call the SpaceX hotline to report something, but if black-suited goons don’t rush to the scene in a Cybertruck, we’ll be disappointed.

If you’ve been around Hackaday for a while, the name Anool Mahidharia will probably be familiar to you. Aside from writing over 300 articles for us, Anool has been a driving force behind The Maker’s Asylum hackspace in Mumbai, where among a ton of other achievements he managed to spearhead the development of an affordable open-source oxygen concentrator during the darkest days of the Covid-19 pandemic. All that was side action on his main gig running test and measurement company Lumetronics. Anool has decided to shut the business down and sell off all the contents of the shop, which contains some really cool machines and equipment. If you’re handy to Mumbai you’ll definitely want to check this out. Anool, we’re not sure what the future holds for you, and we certainly hope you’re not hanging things up for good, but if you are, “So long, and thanks for all the hacks.”

The entire point of a submarine is to be invisible, to dip beneath the waves and imitate a patch of perfectly normal seawater as convincingly as possible. So we mere mortals have very few opportunities to see submarines at all, let alone see one maneuver. But if you’re anywhere near the Heidelberg area, you just might get a chance to see U17, a Type 206 diesel-electric sub that served in the Bundesmarine until 2010, as it’s being moved to its new home at the Technik Museen Sinsheim. A lot of the journey is on barges along the Rhine and Neckar rivers, at least until it arrives in Haßmersheim, whereupon the 90-meter boat will take to the road in a circuitous route to its new home. Can’t get to Germany to watch it in person? No worries — there’s a live stream for that.

Speaking of old tube-shaped objects, we know that compressed gas cylinders are built to last, but one was recently found that’s been in continuous service for over a century. Gas cylinders are subject to periodic inspection, for obvious reasons, and get a date stamped into their neck once they pass. The stalwart cylinder, currently holding carbon dioxide gas, has date stamps going back to 1921, and may even have older stamps lying beneath labels with fancy new-fangled 2D barcodes. Quite a contrast to a date stamped into the steel with a hammer and die, and it only emphasizes how old this thing is and how much of our technological history it has witnessed — so far.

And finally, if you think your job sucks, you’re probably right. But even so, it’s not worth ending it all, as a “civil service robot” apparently did by casting itself down a stairwell. The bot, apparently despondent thanks to a zero-wage, dead-end job that entailed shuffling documents around a municipal office in Gumi, South Korea, was seen rolling about in circles on a landing before taking the fatal plunge, which witnesses seemed to think was deliberate. The robot’s remains were collected and a post-mortem examination is being conducted to see what went wrong. The suicidal robot, built by California start-up Bear Robotics, which disappointingly does not appear to build robotic bears, seemed to have been the only one of its peers with the ability to call elevators and move between floors of its own volition. So maybe it wasn’t so much a suicide but a case of workplace jealousy and murder most foul.

When you buy a cheap ham radio handy-talkie, you usually get a little “rubber ducky” antenna with it. You can also buy many replacement ones that are at least longer. But how good are they? [Learnelectronics] wanted to know, too, so he broke out his NanoVNA and found out that they were all bad, although some were worse than others. You can see the results in the — sometimes fuzzy — video below.

Of course, bad is in the eye of the beholder and you probably suspected that most of them weren’t super great, but they do seem especially bad. So much so, that, at first, he suspected he was doing something wrong. The SWR was high all across the bands the antennas targeted.

It won’t come as a surprise to find that making an antenna work at 2 meters and 70 centimeters probably isn’t that easy. In addition, it is hard to imagine the little stubby antenna the size of your thumb could work well no matter what. Still, you’d think at least the longer antennas would be a little better.

Hams have had SWR meters for years, of course. But it sure is handy to be able to connect an antenna and see its performance over a wide band of frequencies. Some of the antennas weren’t bad on the UHF band. That makes sense because the antenna is physically larger but at VHF the size didn’t seem a big difference.

He even showed up a little real-world testing and, as you might predict, the test results did not lie. However, only the smallest antenna was totally unable to hit the local repeater.

Of course, you can always make your own antenna. It doesn’t have to take much.

[ZXGuesser] has pulled off a true feat of Meccano engineering: building a Meccano Hellschreiber machine. The design is a close replica of the original Siemens Feld-Hell machine as documented here. What is Hellschreiber, you might ask? It’s a very neat method of sending written messages over the air by synchronizing a printing wheel on the receiving end with pulses generated on the transmitter. By quickly moving the print wheel up and down, arbitrary figures can be printed out. If you want to learn more about Hellschreiber, check out this excellent Hackaday post from almost a decade ago!

The Mastodon thread linked above goes into more detail about the difficulty in building this behemoth — and the slight regret of sticking with the authentic QWERTZ keyboard layout! In order to use the Hellschreiber mode, you have to keep up a steady rhythm of typing at about 2.5 characters per second, otherwise, the receiving end will see randomly spaced gaps between each letter. So while having to type at a steady speed [ZXGuesser] also had to work with a slightly different keyboard layout. Despite this difficulty, some very good quality output was generated!

Incredibly, the output looks just like the output from the original, century-old design. We think this is an absolutely incredible accomplishment, and we hope [ZXGuesser] doesn’t follow through on disassembling this amazing replica — or if they do, we hope it’s documented well enough for others to try their hand at it!

Thanks [BB] for the tip!

In the days before integrated circuits became ubiquitous, providing advanced functionality in a single package, designers became adept at extracting the maximum use from discrete components. They’d use clever circuits in which a transistor or other active part would fulfill multiple roles at once, and often such circuits would need more than a little know-how to get working. It’s not often in 2024 that we encounter this style of circuit, but here’s [Maurycy] with a cheap microwave radar module doing just that.

On the board is an RF portion with a single transistor, some striplines, and an SOIC chip. Oddly this last part turns out to be an infra-red proximity sensor chip, so what’s going on? Careful analysis of the RF circuit reveals something clever. As expected, it’s a 3.18 GHz oscillator, but how is it functioning as both transmitter and receiver? The answer comes in the form of a resistor and capacitor in the emitter circuit, which causes the transistor to also oscillate at about 20 kHz. The result is that at different times in the 20 kHz period, the transistor is either off, fully oscillating at 3.18GHz and transmitting, or briefly in the not-quite-oscillating state between the two during which it functions as a super-regenerative receiver. This is enough for one device to effectively transmit and receive at the same time with the minimum of parts, there’s no need for a mixer diode as you might expect if it were it a direct conversion receiver. Perhaps in RF terms, it’s not particularly pretty, but we have to admit to being impressed by its simplicity. He goes on to perform a few experiments with the board as a transmitter or as a more conventional radar.

This isn’t the first such radar module we’ve looked at, here’s one designed from scratch. And we love regens, since they are so simple to build.

Meshtastic is a way to build mesh networks using LoRa that is independent of cell towers, hot spots or traditional repeaters. It stands to reason that with an SDR and GNU Radio, you could send and receive Meshtastic messages. That’s exactly what [Josh Conway] built, and you can see a video about the project, Meshtastic_SDR, below. The video is from [cemaxecuter], who puts the library through its paces.

For hardware, the video uses a Canary I as well as the WarDragon software-defined radio kit which is an Airspy R2 and a mini PC running Dragon OS — a Linux distribution aimed at SDR work —  in a rugged case. GNU Radio, of course, uses flows which are really just Python modules strung together with a GUI.

The GNU blocks send and receive data via TCP port, so using the radio as a data connection is simple enough. The flow graph itself for the receiver looks daunting, but we have a feeling you won’t change the default very much.

If you’ve wanted to dip your toe into Meshtastic or you want a meaty example of using GNU Radio, this would be a fun project to duplicate and extend. While Meshtastic is generally a mesh protocol, you can set up a node to act as a repeater. You never know when decentralized communications might save the day.

Morse code, often referred to as continuous wave (CW) in radio circles, has been gradually falling out of use for a long time now. At least in the United States, ham radio licensees don’t have to learn it anymore, and the US Coast Guard stopped using it even for emergencies in 1999. It does have few niche use cases, though, as it requires an extremely narrow bandwidth and a low amount of power to get a signal out and a human operator can usually distinguish it even if the signal is very close to the noise floor. So if you want to try and learn it, you might want to try something like this Morse trainer from [mircemk].

While learning CW can be quite tedious, as [mircemk] puts it, it’s actually fairly easy for a computer to understand and translate so not a lot of specialized equipment is needed. This build is based around the Arduino Nano which is more than up for the job. It can accept input from any audio source, allowing it to translate radio transmissions in real time, and can also be connected to a paddle or key to be used as a trainer for learning the code. It’s also able to count the words-per-minute rate of whatever it hears and display it on a small LCD at the front of the unit which also handles displaying the translations of the Morse code.

If you need a trainer that’s more compact for on-the-go CW, though, take a look at this wearable Morse code device based on the M5StickC Plus instead.

OK, it’s official: the Quansheng UV-K5 is the king of hackable ham radios — especially now that a second version of the all-band hardware and firmware mod has been released, not to mention a new version of the radio.

If you need to get up to speed, check out our previous coverage of the all-band hack for the UV-K5, in which [Paul (OM0ET)] installs a tiny PCB to upgrade the radio’s receiver chip to an Si4732. Along with a few jumpers and some component replacements on the main board, these hardware mods made it possible for the transceiver, normally restricted to the VHF and UHF amateur radio bands, to receive everything down to the 20-meter band, in both AM and single-sideband modulations.

The new mod featured in the video below does all that and more, all while making the installation process slightly easier. The new PCB is on a flexible substrate and is considerably slimmer, and also sports an audio amplifier chip, to make up for the low audio output on SSB signals of the first version. Installation, which occupies the first third of the video below, is as simple as removing one SMD chip from the radio’s main board and tacking the PCB down in its footprint, followed by making a couple of connections with very fine enameled wire.

You could load the new firmware and call it a day at that point, but [Paul] decided to take things a step further and install a separate jack for a dedicated HF antenna. This means sacrificing the white LED on the top panel, which isn’t much of a sacrifice for most hams, to make room for the jack. Most of us would put a small SMA jack in, but [Paul] went for a BNC, which required some deft Dremel and knife work to fit in. He also used plain hookup wire to connect the jack, which sounds like a terrible idea; we’d probably use RG-316, but his mod didn’t sound that bad at all.

Keen to know more about the Quansheng UV-K5? Dive into the reverse-engineered schematics.

Thanks to [Sam] for the heads up on this one.

We’ve said it before and we’ll say it again: being able to build your own radios is the best thing about being an amateur radio operator. Especially low-power transmitters; there’s just something about having the know-how to put something on the air that’ll reach across the planet on a power budget measured in milliwatts.

This standalone WSPR beacon is a perfect example. If you haven’t been following along, WSPR stands for “weak-signal propagation reporter,” and it’s a digital mode geared for exploring propagation that uses special DSP algorithms to decode signals that are far, far down into the weeds; signal-to-noise ratios of -28 dBm are possible with WSPR.

Because of the digital nature of WSPR encoding and the low-power nature of the mode, [IgrikXD] chose to build a standalone WSPR beacon around an ATMega328. The indispensable Si5351 programmable clock generator forms the RF oscillator, the output of which is amplified by a single JFET transistor. Because timing is everything in the WSPR protocol, the beacon also sports a GPS receiver, ensuring that signals are sent only and exactly on the even-numbered minutes. This is a nice touch and one that our similar but simpler WSPR beacon lacked.

This beacon had us beat on performance, too. [IgrikXD] managed to hit Texas and Colorado from the edge of the North Sea on several bands, which isn’t too shabby at all with a fraction of a watt.

Thanks to [STR-Alorman] for the tip.

[via r/amateurradio]

We’ve been harping a lot lately about the effort by carmakers to kill off AM radio, ostensibly because making EVs that don’t emit enough electromagnetic interference to swamp broadcast signals is a practical impossibility. In the US, push-back from lawmakers — no doubt spurred by radio industry lobbyists — has put the brakes on the move a bit, on the understandable grounds that an entire emergency communication system largely centered around AM radio has been in place for the last seven decades or so. Not so in Japan, though, as thirteen of the nation’s 47 broadcasters have voluntarily shut down their AM transmitters in what’s billed as an “impact study” by the Ministry of Internal Affairs and Communications. The request for the study actually came from the broadcasters, with one being quoted in a hearing on the matter as “hop[ing] that AM broadcasting will be promptly discontinued.” So the writing is apparently on the wall for AM radio in Japan.

There was another close call this week with our increasingly active sun, which tried but didn’t quite launch a massive stream of plasma out into space. The M-class flare was captured in the act by the Solar Dynamics Observatory, which keeps an eye on what’s going on with our star. The video of the outburst is fascinating; it almost looks like a CGI render, but it’s real imaging and pretty spectacular. The active region on the sun’s surface suddenly belches out a few gigatons of plasma, which quickly get sucked right back down to the surface. You can actually see the material following ethereal lines of magnetic force, and the way it splashes when it hits the surface is just beautiful. Seeing this puts us in the mood for a feature on the SDO and how it gets these fascinating images, so stay tuned for that.

Also in space news, we’re saddened by the sudden loss of yet another of the Apollo astronauts. Bill Anders, lunar module pilot on Apollo 8, died Friday in a small plane crash off San Juan Island in Washington. Anders, 90, was piloting the Beechcraft T-34 Mentor, a single-engine military trainer aircraft from the 1950s. Anders’ only trip in space was Apollo 8, but what a trip it was. Along with Commander Frank Borman and pilot James Lovell, they were the first humans to leave Earth’s gravity well and visit another world, riding the mighty Saturn V rocket all the way to the Moon for a ten-orbit visit that paved the way for the landing on Apollo 11. He is also officially the luckiest photographer in history, having been in just the right place at just the right time to snap the famous “Earthrise” picture that gave us for the first time a Moon’s-eye-view of our fragile little world:

Godspeed, Major General Anders.

In more mundane news, a story from Maryland that should give anyone who depends on tools for a living a moment’s pause. Police cracked a massive tool-theft ring thanks to the actions of a carpenter who, sick of having his tools ripped off repeatedly, stashed a couple of AirTags among his stock in trade. When the inevitable occurred and his tools took a walk yet again, he tracked them to a storage facility and alerted police. They in turn conducted an investigation and got search warrants for twelve locations, where the scale of this criminal enterprise became apparent. Check out the photos in the story; mountains of cordless tools sorted by brand, DeWalt yellow here and Milwaukee red there. There’s a surprising amount of puke-green Ryobi, too; are people really trying to make money with those tools? Between the piles of cordless tools and the rows of air compressors, the total value of the haul is estimated to be from $3 to $5 million. Hats off to the carpenter for running his own mini-sting operation.

And finally, from the Genuinely Interesting Apps files we have ShadeMap, which does exactly what you think it does: plot shade and shadow on a map. It has controls for time and date, and zooms down to a pretty fine level of detail, even for the free version. Shadows from buildings, terrain, and trees are calculated and displayed, making it perfect for surveys of locations for solar power installations. There’s also supposed to be a way to virtually remove shadow-casting features, although we couldn’t find it; perhaps in a paid version? That would be a handy tool indeed to see which trees need to be cut down or which buildings demolished to improve your solar aspect. YMMV on that last one, of course.

Are you tired of the same old music, but can’t afford any new tunes, even if they’re on dead formats? Boy, do we know that feeling. Here’s what you do: build yourself a GlobeTune music player, and you’ll never want for new music again.

The idea is simple, really. Just turn what we assume is a nice, clicky knob, and after a bit of static (which is a great touch!), you get a new, random radio station from somewhere around the globe. [Alexis D.] originally built this as a way to listen to and discover new music while disconnecting from the digital world, and we think it’s a great idea.

[Alexis D.] has production in mind, so after a Raspberry Pi Zero W prototype, they set about redesigning it around the ESP32. The current status seems to be hardware complete, software forthcoming. [Alexis D.] says that a crowdfunding campaign is in the works, but that the project will be open-sourced once in an acceptable state. So stay tuned!

Speaking of dead-ish formats, here’s an Internet radio in a cassette form factor.

We’ve all been there. You left your Walkman at home and only have your trusty Game Boy. You want to take a break and just listen to some tunes. What to do? [orangeglo] has the answer now with the Orange FM cartridge.

This prototype cart features an onboard antenna or can also use the 3.5 mm headphone/antenna port on the cartridge to boost reception with either a dedicated antenna or a set of headphones. Frequencies supported are 64 – 108 Mhz, and spacing can be set for 100 or 200 kHz to accomodate most FM broadcasts setups around the world.

Older Game Boys can support audio through the device itself, but Advances will need to use the audio port on the cartridge. The Super Game Boy can pipe audio to your TV though, which seems like a delightfully Rube Goldberg-ian way to listen to the radio. Did we mention it also supports RDS, so you’ll know what that catchy tune is? Try that FM Walkman!

Can’t decide between this and your other carts? Try this revolving multi-cart solution. Have a Game Boy that needs some restoration? If it’s due to electrolyte damage, maybe start here?

Stay in the amateur radio hobby long enough and you might end up with quite a collection of antennas. With privileges that almost extend from DC to daylight, one antenna will rarely do everything, and pretty soon your roof starts to get hard to see through the forest of antennas. It may be hell on curb appeal, but what’s a ham to do?

One answer could be making one antenna do the work of two, as [Guido] did with this diplexer for dual APRS setups. Automatic Packet Reporting System is a packet radio system used by hams to transmit telemetry and other low-bandwidth digital data. It’s most closely associated with the 2-meter ham band, but [Guido] has both 2-meter (144.8-MHz) and 70-cm LoRa (433.775-MHz) APRS IGates, or Internet gateway receivers. His goal was to use a single broadband discone antenna for both APRS receivers, and this would require sorting the proper signals from the antenna to the proper receiver with a diplexer.

Note that [Guido] refers to his design as a “duplexer,” which is a device to isolate and protect a receiver from a transmitter when they share the same antenna — very similar to a diplexer but different. His diplexer is basically a pair of filters in parallel — a high-pass filter tuned to just below the 70-cm band, and a low-pass filter tuned just above the top of the 2-m band. The filters were designed using a handy online tool and simulated in LTSpice, and then constructed in classic “ugly” style. The diplexer is all-passive and uses air-core inductors, all hand-wound and tweaked by adjusting the spacing of the turns.

[Guido]’s diplexer performs quite well — only a fraction of a dB of insertion loss, but 45 to 50 dB attenuation of unwanted frequencies — pretty impressive for a box full of caps and coils. We love these quick and dirty tactical builds, and it’s always a treat to see RF wizardry in action.

In the 1960s, if you were a teenager in the United States, a big part of your life was probably music. There was a seemingly endless supply of both radio stations and 45s to keep you entertained. In the UK and other countries, though, the government held a monopoly on broadcasting, and they were not always enthralled with the music kids liked. Where there is demand, there is an opportunity, and several enterprising broadcasters set up radio stations at sea, the so-called pirate radio stations. In 1964, Irish businessman [Ronan O’Rahilly] did just this and founded Radio Caroline. Can you imagine that 60 years later, Radio Caroline is still around?

Not that it has been in operation for 60 years in a row. There were a few years the station’s ship had been impounded by creditors. Then, the ship ran aground on the Goodwin Sands and was damaged. You can see a news short from 1965 in the video below (Radio Caroline shows up at about the 1:50 mark).

True, Radio Caroline isn’t quite the same as it was. They operate mostly from a legal onshore studio now. But one weekend a month, a crew operates from the ship now in British waters.

Back in 1964, you might have had problems picking up Radio Caroline from far away. Now, the pirate station is as close as your web browser. The other big pirate station was RNI, and they are still around, too.

[Alex R2AUK] has been busy creating version two of a homebrew all-band ham radio transceiver. The unit has a number of features you don’t always see in homebrew radios. It covers the 80, 40, 30, 20, 17, 15, 12, and 10 meter bands. The receiver is a single-IF design with AGC. The transmitter provides up to 10W for CW and 5W for single sideband operations. There’s a built-in keyer, too. A lot of the documentation is in Russian (including the video below, which is part of a playlist). But translation tools are everywhere, so if you don’t speak Russian, you can still probably figure it out.

The VFO for both transmit and receive is an Si5351. The transmit chain is straightforward. The receiver reuses many of the same filters.

Like many projects these days, an attractive 3D-printed case gives the radio a polished look. If you prefer using a straight key to a keyer, the transmitter will use either. The microphone amplifier has built-in compression for good audio levels.

If you don’t want to roll your own, you can get similar ham gear that is ready-built. If you want to go minimal. we’ve seen a less-capable transceiver built with only seven transistors.

A perk of writing for Hackaday comes in the vast breadth of experience represented by our fellow writers. Through our colleague [Voja Antonić] for example we’ve gained an unparalleled insight into the cutting edge of 8-bit computing in 1980s Yugoslavia, of his Galaksija home computer, and of software being broadcast over [Zoran Modli]’s Ventilator 202 radio show.

We’re strongly reminded of this by hearing of the Slovenian Radio Študent broadcasting the classic Slovenian ZX Spectrum text adventure game Kontrabant 2, at the behest of the  Slovenian Computer History Museum. It’s been four decades and a lot of turbulent history, but once again 8-bit code will be heard on FM in Europe.

Some of our younger readers may never have experienced the joy of loading software from cassette, but in those days it represented a slow alternative to the eye-wateringly expensive floppy drives of the day. The software was represented as a serial bitstream translated into tones and recorded on a standard cassette recorder which was standard consumer electronics back then, and when played back through a speaker it was an ear-splitting sound with something in common with that of a modem handshake from a decade or more later. This could easily be transmitted over a radio station, and a few broadcasters tried experimental technology shows doing just that.

We haven’t heard from any listeners who managed to catch the game and run it on their Spectrum, but we hope that Slovenia’s retrocomputing community were out in force even if Audacity and a n emulator replaced the original hardware. Given that more than one hacker camp in our community has sported radio stations whether legal or not, it would be nice to hear the dulcet tones of 8-bit software on the airwaves again.

Meanwhile if cassettes are too cheap for you, feast your eyes on Sir Clive’s budget storage solution.

Thanks [Stephen Walters].

The Altoids tin has long been the enclosure of choice for those seeking to show off their miniaturization chops. This is especially true for amateur radio homebrewers — you really have to know what you’re doing to stuff a complete radio in a tiny tin. But when you can build an entire 80-meter transceiver in a matchbox, that’s a whole other level of DIY prowess.

It’s no surprise that this one comes to us from [Helge Fykse (LA6NCA)], who has used the aforementioned Altoids tin to build an impressive range of “spy radios” in both vacuum tube and solid-state versions. He wisely chose solid-state for the matchbox version of the transceiver, using just three transistors and a dual op-amp in a DIP-8 package. There’s also an RF mixer in an SMD package; [Helge] doesn’t specify the parts, but it looks like it might be from Mini-Circuits. Everything is mounted dead bug style on tiny pieces of copper-clad board that get soldered to a board just the right size to fit in a matchbox.

A 9 volt battery, riding in a separate matchbox, powers the rig. As do the earbud and tiny Morse key. That doesn’t detract from the build at all, and neither does the fact that the half-wave dipole antenna is disguised as a roll of fishing line. [Helge]’s demo of the radio is impressive too. The antenna is set up very low to the ground to take advantage of near vertical incidence skywave (NVIS) propagation, which tends to direct signals straight up into the ionosphere and scatter them almost directly back down. This allows for medium-range contacts like [Helge]’s 239 km contact in the video below.

Banging out Morse with no sidetone was a challenge, but it’s a small price to pay for such a cool build. We’re not sure how much smaller [Helge] can go, but we’re eager to see him try.