Hackaday Podcast Episode 248: Cthulhu Clock Radio Transharmonium, Thunderscan, And How To Fill Up In Space

Note: This article is a fully rewritten, SEO-focused editorial synthesis based on real public information from Hackaday’s episode notes and related technical background from NASA/JPL, NASA Science, Emily Francisco’s project documentation, MIT Lemelson, FCC-related radio guidance, and other reputable technical references.

A Wild Tour Through Hardware, Spaceflight, Retro Computing, And Beautifully Questionable Ideas

Some podcast episodes politely stay in one lane. Hackaday Podcast Episode 248 does not. It drives a hand-built Cthulhu clock radio through a museum, swerves into a spark-gap transmitter, parks beside an Apple ImageWriter that somehow became a scanner, then launches the whole thing toward orbital refueling. In other words, it is exactly the sort of gloriously chaotic engineering buffet that makes Hackaday so addictive.

Released in December 2023, the episode brought together Elliot Williams and Dan Maloney for the penultimate Hackaday Podcast of the year. The conversation moved through space news, oddball musical hardware, high-voltage radio experiments, homemade optics, retro computer peripherals, cyanoacrylate chemistry, paper tape readers, suspicious 6502 chips, and the future of “filling up” spacecraft in orbit. That sounds like too much for one episode, but in the Hackaday universe, that is basically a light snack.

The real charm of this episode is not just the topic list. It is the way each story shows a different side of engineering culture: art built from obsolete consumer gear, science experiments built from dangerous-looking benches, old products that solved problems with absurd elegance, and space systems where a label can matter as much as a rocket engine.

The Trans-Harmonium: When Clock Radios Become A Creature From The Audio Deep

The title’s “Cthulhu Clock Radio Transharmonium” refers to one of the episode’s most memorable subjects: Emily Francisco’s Trans-Harmonium, a deconstructed antique piano wired to play a collection of clock radios. Each key corresponds to a radio frequency. Pressing a key does not strike a string; it activates a radio. Suddenly, the “instrument” is not making sound so much as summoning sound from the air.

That is why the project feels wonderfully strange. It is part keyboard, part sculpture, part time capsule, and part haunted appliance aisle. The artist’s documentation describes the Trans-Harmonium as a listening station that uses local radio frequencies to create audible portraits of different cities. C is generally reserved for classical music when possible, while other natural notes are assigned to local stations. Sharps and flats are tuned between stations, gathering static, fragments of speech, overlapping music, and ghostly electromagnetic leftovers.

This is not an instrument you master in the traditional sense. Nobody is shredding a jazz solo on it while the crowd screams for an encore. The point is more conceptual: every performance is local, temporary, and impossible to repeat exactly. The same key pressed in Washington, D.C., Boulder, Philadelphia, or Baltimore may produce an entirely different sonic world. It is a reminder that radio is not just technology. It is atmosphere, geography, culture, weather, and time, all squeezed through a speaker that probably once lived on someone’s nightstand.

Modern Spark Gap Transmitters: Fun, Dangerous, And Probably Not Neighbor-Friendly

The episode also touched on a modern spark-gap transmitter using a rotary gap. Spark-gap radio belongs to the earliest era of wireless communication, when high-voltage sparks generated radio-frequency energy that could be keyed into Morse code. It was dramatic, noisy, and visually satisfying. It was also spectacularly messy from a spectrum perspective.

In the Hackaday-covered project, the builder used modern components such as a signal generator and FET driver, but the basic spirit remained old-school: an ignition coil, tank circuit, and spark gap producing a signal that could be heard in a receiver. Adjusting the spark frequency changed the audible tone, which makes the experiment fascinating as a demonstration of early wireless principles.

However, this is the point where the responsible adult enters the room wearing safety glasses and holding a clipboard. Spark-gap transmitters produce broadband RF emissions that can interfere with other services. That is why modern discussions of spark-gap radio usually come with a large “do not transmit this into an antenna unless you really know the law and the physics” warning. It is educational, historical, and cool in the same way a trebuchet is cool: excellent to study, less excellent when launched across a suburban fence.

Raman Lasers: Shaking Light Until It Changes Its Mind

Another highlight was the homemade Raman laser. Raman scattering is one of those physics concepts that sounds like it escaped from a graduate textbook after drinking espresso. In simple terms, when intense light interacts with certain materials, some of that light can emerge at a different frequency. In a Raman laser, that effect is encouraged, amplified, and organized into coherent laser output.

The project discussed in the episode used a high-power green pump laser and a gain medium such as dimethyl sulfoxide, or DMSO. The build demonstrated that a 532 nm input could produce output around 628 nm, verified with a spectrometer. That is the kind of result that makes optics people grin and everyone else quietly check whether the laser goggles are rated correctly.

What makes this project valuable is not merely that it works. It shows how advanced scientific ideas can be explored outside institutional laboratories by careful, knowledgeable experimenters. Of course, lasers are not toys. High-power optical systems demand real safety practices. But as a learning story, the Raman laser is a beautiful example of theory becoming hardware, then hardware becoming a visible beam on a bench.

ThunderScan: The Scanner That Pretended To Be A Printer Accessory

Then comes ThunderScan, a product from the 1980s that turned an Apple ImageWriter dot-matrix printer into a scanner. If that sounds like making a toaster into a fax machine, you are not far off. The idea was wonderfully practical for its time. Printers were expensive. Scanners were rare. Home computer graphics were limited. So Thunderware built a scanning head that rode on the printer mechanism and used the ImageWriter’s own motion system to scan a page.

The genius was in how the data reached the Macintosh. The scanner used an optical reflective sensor to read the page. Instead of sending image data through normal serial lines, the analog sensor output was converted into a frequency signal that toggled a serial handshake line. The software measured the rate of those toggles to infer light and dark areas. Faster toggling meant darker pixels; slower toggling meant lighter ones.

That is the kind of hack that makes modern engineers both laugh and applaud. It is not elegant in the glossy, product-video sense. It is elegant in the “we found a path through the wall using a spoon and three undocumented assumptions” sense. ThunderScan represents a time when computing accessories often solved problems by bending existing hardware into new shapes.

Voyager 1 And OSIRIS-REx: Space Missions Are Debugging With Terrible Latency

The episode opened with space news, including concern over Voyager 1’s flight data system anomaly. Voyager 1, launched in 1977, had already become one of humanity’s most astonishing machines by the time this episode aired. But in late 2023, the spacecraft began returning unusable data patterns, creating a deep-space troubleshooting problem with an almost comical delay: a command could take about 22.5 hours to reach the spacecraft, and another 22.5 hours for the response to return.

That means debugging Voyager is not like fixing a laptop. It is more like sending a postcard to a 1970s computer in interstellar space and hoping it replies with something other than cosmic gibberish. NASA’s later work showed the issue involved the flight data subsystem memory, and engineers eventually restored usable engineering updates by relocating affected code. It was an extraordinary reminder that software maintenance can become archaeology when the hardware is older than most people on the engineering team.

The episode also discussed the OSIRIS-REx sample return capsule and its drogue parachute issue. The capsule safely delivered asteroid Bennu material to Earth, but the landing sequence did not go perfectly. NASA identified inconsistent wiring label definitions as the likely cause. The word “main” was used in two different ways in different parts of the system, leading to parachute deployment actions happening out of order.

The lesson is brutal and useful: labels matter. In space engineering, a naming mismatch is not a minor paperwork inconvenience. It can change the behavior of a system traveling at terrifying speed through the atmosphere. Luckily, the main parachute handled the capsule’s faster-than-planned descent, and the Bennu sample was recovered safely.

Super Glue, Fake Chips, And The Everyday Weirdness Of Engineering

The “can’t-miss” portion of the episode also included super glue, one of the great accidental inventions. Cyanoacrylates were originally investigated in the 1940s by Harry Coover and colleagues while searching for clear plastics suitable for precision gun sights. The compounds were rejected because they stuck to almost everything. Years later, Coover recognized the same property as the feature, not the bug.

That is a classic invention pattern: the first person sees failure; the second look sees a product. Super glue cures rapidly in the presence of moisture, which explains why it bonds skin so enthusiastically. It is the tiny goblin of the workshop: incredibly useful, always nearby, and absolutely waiting for a chance to attach your fingers to the enclosure you were “just test fitting.”

The episode also nodded toward hardware fakery, including questionable 6502 chips and misleading markings. Counterfeit or relabeled components are a recurring problem in electronics, especially for retrocomputing and repair communities. A part can look right, carry the expected markings, and still behave like a raccoon wearing a lab coat. For makers, the lesson is simple: trust datasheets, test behavior, buy from reliable suppliers when possible, and keep skepticism on the bench next to the multimeter.

How To Fill Up In Space: Orbital Refueling And The Artemis Future

The title’s “How To Fill Up In Space” points to one of the most important engineering problems in modern lunar exploration: orbital refueling. NASA’s Artemis program aims to return astronauts to the Moon and eventually support more sustained lunar activity. But large lunar landers such as SpaceX’s Starship Human Landing System and Blue Origin’s Blue Moon architecture depend heavily on moving propellant in space.

Why? Because rockets are ruled by mass. A lunar lander that can carry crew, cargo, life-support systems, engines, tanks, and return propellant becomes enormous. Launching everything fully fueled from Earth is difficult or impractical. Instead, the idea is to launch the lander, then refill or top it off in orbit using tanker vehicles or propellant storage systems.

That sounds straightforward until you remember that cryogenic propellants are extremely cold, boil-off is a problem, fluids behave strangely in microgravity, docking must be precise, and valves, pumps, seals, insulation, and transfer lines must work perfectly in space. On Earth, filling a vehicle is routine. In orbit, it becomes ballet performed by robots while everyone involved sweats through their polo shirts.

Still, orbital refueling could change spaceflight. If spacecraft can be refueled beyond Earth’s surface, missions no longer have to carry every drop of propellant from launch to destination. That opens the door to heavier payloads, reusable vehicles, lunar logistics chains, Mars mission planning, and infrastructure that looks less like one-off exploration and more like transportation.

Why Episode 248 Works So Well For Makers And Engineers

What ties all these topics together is the Hackaday mindset. The episode is not just a list of “cool stuff.” It is a tour of how people repurpose, misunderstand, repair, overbuild, label, relabel, and reimagine technology. A clock radio becomes a city-sampling instrument. A printer becomes a scanner. A dangerous old radio method becomes a teaching tool. A chemical mistake becomes a household essential. A spacecraft glitch becomes a masterclass in remote debugging.

For readers interested in hardware hacking, retrocomputing, space technology, radio experiments, and DIY science, Hackaday Podcast Episode 248 is especially rich because it connects big systems with small details. The same episode that talks about lunar propellant transfer also cares about serial port handshaking. That contrast is the whole point: engineering is not only about big rockets. It is about connectors, labels, pins, adhesives, tolerances, and the occasional clock radio that looks like it is preparing to summon an elder god.

Experience Section: What This Episode Feels Like From A Maker’s Bench

Listening to an episode like this feels a lot like standing in a crowded workshop where every table has a different obsession. On one bench, someone is carefully restoring a vintage computer. On another, someone is aligning optics and whispering “please don’t blind me” with professional sincerity. Across the room, a radio experimenter is making noises that would worry the FCC, while an artist is turning obsolete consumer electronics into something oddly emotional. It is chaotic, but it is the productive kind of chaos.

The Trans-Harmonium section especially captures what many makers secretly love about old hardware. A clock radio is not glamorous. It is the object you ignore until a hotel alarm goes off at 5:00 a.m. because the previous guest was a monster. Yet in Francisco’s project, those forgettable devices become a living instrument. That shift is powerful. It proves that creative engineering does not always begin with expensive parts. Sometimes it begins with noticing that a boring object still has one strange, useful behavior left inside it.

ThunderScan hits a different nerve. Anyone who has repaired or modified old computer gear knows the joy of discovering a design that should not work but absolutely does. Modern devices often hide their decisions behind sealed cases and firmware updates. Older machines expose their compromises. You can see the path the designer took: the available port, the available sensor, the mechanical motion already provided by the printer, and the software trick that stitched it together. It feels like solving a puzzle alongside someone from 40 years ago.

The space stories add humility. It is easy to joke about wiring labels or delayed telemetry until you realize how unforgiving the environment is. Voyager 1 is so far away that a single troubleshooting cycle takes almost two days. OSIRIS-REx carried asteroid material across space and still had to depend on labels, pyrotechnics, parachutes, and documentation behaving as expected. These stories make ordinary workshop habits feel more important. Label wires clearly. Keep notes. Test assumptions. Future-you may not be debugging from interstellar space, but future-you will still appreciate not having to guess which red wire was “main.”

Orbital refueling, meanwhile, is the episode’s big-picture inspiration. It suggests that the next era of exploration may depend less on one giant heroic launch and more on infrastructure: depots, tankers, transfer systems, repeatable docking, and boring reliability. That is encouraging for makers because infrastructure is where small improvements matter. Better valves, better sensors, better software, better insulation, better proceduresnone of it sounds as cinematic as “Moon landing,” but without it, the cinematic moment never happens.

That is the lasting experience of Episode 248: it makes technology feel wonderfully human. Brilliant, risky, funny, fragile, improvised, and occasionally sticky with super glue.

Conclusion

Hackaday Podcast Episode 248: Cthulhu Clock Radio Transharmonium, Thunderscan, And How To Fill Up In Space is a compact snapshot of why hardware culture remains so entertaining and important. It celebrates projects that are strange enough to be memorable and technical enough to teach something real. From the Trans-Harmonium’s radio-fed art to ThunderScan’s serial-port trickery, from Voyager’s deep-space debugging to the promise of orbital refueling, the episode reminds us that engineering is rarely clean and linear. It is messy, clever, funny, risky, and full of surprises.

The best hacks do more than solve problems. They reveal hidden possibilities in ordinary objects. A clock radio can become an instrument. A printer can become a scanner. A labeling mistake can become a spaceflight lesson. A refueling problem can reshape lunar exploration. That is why this episode still matters: it captures the maker spirit in all its solder-scented glory.