Author: Al Williams

4427 Articles

Heathkit Tuner Saved From Junk Pile

April 4, 2026 by No comments

We miss the old Heathkit. You could build equipment that rivaled or even surpassed commercial devices. The cost was usually reasonable and, even if you could get by with less, the satisfaction of using gear you built yourself was worth a lot. Not to mention the knowledge you’d gain and your confidence in troubleshooting should the need arise. So we were jealous of [RCD66] when he found a Heathkit AJ-43C stereo tuner in the recycle bin.

As you can see in the video below, it needed a lot of love to get back to its former self. The device dates from around 1965, when the kit cost $130. In 1965, that was a lot of money. Back then, that would have bought you about four ounces of gold and would have been a great down payment on a $1,500 VW bug.

Things were a bit of a mess, so he removed all the parts and replaced most of them. Unsurprisingly, the electrolytic capacitors all tested bad. The transistors were all germanium, but if they tested good, his plan was to reuse them. There were several PCBs inside, and he made some changes, such as replacing the zener diode power supply with something more modern.

How did it sound? Watch the video and see for yourself. We usually like troubleshooting specific problems on gear like this, but in this case, it was probably smart to just do a total rework.

Heathkit had quite an origin story. This isn’t the first time we’ve seen someone strip and rebuild a Heathkit.

Continue reading “Heathkit Tuner Saved From Junk Pile” →

Ask Hackaday: Using CoPilot? Are You Entertained?

April 1, 2026 by 51 Comments

There’s a great debate these days about what the current crop of AI chatbots should and shouldn’t do for you. We aren’t wise enough to know the answer, but we were interested in hearing what is, apparently, Microsoft’s take on it. Looking at their terms of service for Copilot, we read in the original bold:

Copilot is for entertainment purposes only. It can make mistakes, and it may not work as intended. Don’t rely on Copilot for important advice. Use Copilot at your own risk.

While that’s good advice, we are pretty sure we’ve seen people use LLMs, including Copilot, for decidedly non-entertaining tasks. But, at least for now, if you are using Copilot for non-entertainment purposes, you are violating the terms of service.

Continue reading “Ask Hackaday: Using CoPilot? Are You Entertained?” →

Spy Tech: Conflicts Bring A New Number Station

March 30, 2026 by 21 Comments

If you know much about radios and espionage, you’ve probably encountered number stations. These are mysterious stations that read out groups of numbers or otherwise encoded messages to… well… someone. Most of the time, we don’t know who is receiving the messages. You’d be excused for thinking that this is an old technology. After all, satellite phones, the Internet, and a plethora of options now exist to allow the home base to send spies secret instructions. However, the current-day global conflict has seen at least one new number station appear, apparently associated with the United States and, presumably, targeting some recipients in Iran, according to priyom.org.

As you might expect, these stations don’t identify themselves, but the Enigma Control List names this one as V32. It broadcasts two two-hour blocks a day at 0200 UTC and a repeat at 1800 UTC. Each message starts with the Farsi word for “attention” followed by what is assumed to be some header information as two 5-digit groups. Then there is a set of 181 five-digit groups. Each message is padded out to take 20 minutes, and there are six messages in each transmission.

Continue reading “Spy Tech: Conflicts Bring A New Number Station” →

Hackaday Podcast Episode 363: The History Of PLA, Laser DIY PCBs, And Corporate Craziness

March 27, 2026 by 9 Comments

What did Elliot Williams and Al Williams read on Hackaday last week? Tune in and find out. After a bit of news, [Vik Oliver] chimes in with some deep PLA knowledge. Then the topic changed to pressure advance measurements, SDRs, making super-resolution PCBs with a fiber laser, and more.

Want to 3D print wire strippers? A robot arm? Or just make your own Z-80? Those hacks are in there, too.

For the long articles, we talked about old tech, including the :CueCat and the Iomega Zip Drive. Let us know if you had either one in the comments.

What do you think? Leave us a comment or record something and send it to our mailbag.

Download a copy of the podcast with no corporate trackers in the clean MP3.

Where to Follow Hackaday Podcast

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Retail Fail: The :CueCat Disaster

March 25, 2026 by 71 Comments

Digital Convergence Corporation is hardly a household name, and there’s a good reason for that. However, it raised about $185 million in investments around the year 2000 from companies such as Coca-Cola, Radio Shack, GE, E. W. Scripps, and the media giant Belo Corporation. So what did all these companies want, and why didn’t it catch on? If you are old enough, you might remember the :CueCat, but you probably thought it was Radio Shack’s disaster. They were simply investors.

The Big Idea

The :CueCat was a barcode scanner that, usually, plugged into a PC’s keyboard port (in those days, that was normally a PS/2 port). A special cable, often called a wedge, was like a Y-cable, allowing you to use your keyboard and the scanner on the same port. The scanner looked like a cat, of course.

However, the :CueCat was not just a generic barcode scanner. It was made to only scan “cues” which were to appear in catalogs, newspapers, and other publications. The idea was that you’d see something in an ad or a catalog, rush to your computer to scan the barcode, and be transported to the retailer’s website to learn more and complete the purchase.

The software could also listen using your sound card for special audio codes that would play on radio or TV commercials and then automatically pop up the associated webpage. So, a piece of software that was reading your keyboard, listening to your room audio at all times, and could inject keystrokes into your computer. What could go wrong?

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Linux Fu: UPNP A Port Mapping Odyssey

March 23, 2026 by 6 Comments

If you’ve ever run a game server or used BitTorrent, you probably know that life is easier if your router supports UPnP (Universal Plug and Play). This is a fairly old tech — created by a standards group in 1999 — that allows a program to open an incoming port into your home network. Of course, most routers let you do this manually, but outside of the Hackaday universe, most people don’t know how to log into their routers, much less how to configure an open UDP port.

I recently found myself using a temporary setup where I could not access the router directly, but I needed some open ports. That got me thinking: if a program can open a port using UPnP, why can’t I? Turns out, of course, you can. Maybe.

Caveats

The first thing, of course, is that you need your firewall open, but that’s true no matter how you open up the router. If the firewall is in the router, then you are at the mercy of the router firmware to realize that if UPnP opens something up, it needs to open the firewall, too.

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The Zero-Power Flight Computer

March 23, 2026 by 27 Comments

In the early days of aviation, pilots or their navigators used a plethora of tools to solve common navigation and piloting problems. There was definitely a need for some kind of computing aid that could replace slide rules, tables, and tedious dead-reckoning computations. This would become even more important during World War II, when there was a massive push to quickly train young men to be pilots.

The same, but different. A Pickett slide rule (top) and an E6B slide rule (bottom). (Own Work).

Today, we’d whip up some sort of computer device, but in the 1930s, computers weren’t anything you’d cram on a plane, even if they’d had any. For example, the Mark 1 Fire Control Computer during WW2 was 3,000 pounds of gears and motors.

The computer is made to answer flight questions like “how many pounds of fuel do I need for another hour of flying time?” or “How do I adjust my course if I have a particular crosswind?”

History

There were a rash of flight computers starting in the 1920s that were essentially specialized slide rules. The most popular one appeared in the late 1930s. Philip Dalton’s circular slide rule was cheap to produce and easy to use. As you’ll see, it is more than just an ordinary slide rule. Keep in mind, these were not computers in the sense we think of today. They were simple slide rules that easily did specialized math useful to pilots.

Dalton actually developed a number of computers. The popular Model B appeared in 1933, and there were refinements leading to additional models. The Mark VII was very popular. Even Fred Noonan, Amelia Earhart’s navigator, used a Mark VII. Continue reading “The Zero-Power Flight Computer” →