Restoring The Soul Of A 1940s Radio

Although we do often see projects that take antiques and replace some or all of their components with modern equipment, we can also sympathize with the view that (when possible and practical) certain antique electronics should be restored rather than gutted. [David] has this inclination for his 1948 GE radio, but there are a few issues with it that prevented a complete, period-correct restoration.

The main (pun intended) issue at the start of this project was safety. The original radio had a chassis that was just as likely as not to become energized, with the only protection being the plastic housing. [David] set up an isolation transformer with a modern polarized power cable to help solve this issue, and then got to work replacing ancient capacitors. With a few other minor issues squared away this is all it took to get the radio working to receive AM radio, and he also was able to make a small modification to allow the radio to accept audio via a 3.5mm jack as well.

However, [David] also has the view that a period-correct AM transmission should accompany this radio as well and set about with the second bit of this project. It’s an adaptation of a project called FieldStation42 originally meant to replicate the experience of cable TV, but [Shane], the project’s creator, helped [David] get it set up for audio as well. A notable feature of this system is that when the user tunes away from one station, it isn’t simply paused, but instead allowed to continue playing as if real time is passing in the simulated radio world.

Although there are a few modern conveniences here for safety and for period-correct immersion, we think this project really hits the nail on the head for preserving everything possible while not rolling the dice with 40s-era safety standards. There’s also a GitHub page with some more info that [David] hopes to add to in the near future. This restoration of a radio only one year newer has a similar feel, and there are also guides for a more broad category of radio restorations as well.

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Detecting Helium Leaks With Sound In A Physics-Based Sensor

Helium is inert, which makes it useful in a lot of different industries. But helium’s colorless and odorless non-reactivity also means traditional gas sensing methods don’t work. Specialized detectors exist, but are expensive and fussy. Thankfully, researcher [Li Fan] and colleagues found a physics-based method of detecting helium that seems as elegant as it is simple.

The new sensor relies on a topological kagome structure, and doesn’t depend on any chemical reaction or process whatsoever. The cylinders in the structure are interconnected; air can flow in and speakers at the three corners inject sound.

Sound waves propagate through the air within the structure at a fixed rate, and as helium enters the sensor it changes how fast the sound waves travel. This measurable shift in vibration frequency indicates the concentration of helium. It’s stable, calibration-free, doesn’t care much about temperature, and resets quickly. Even better, the three corners act as separate sensors, making it directional. It’s even quite rugged. Just as a basket weaved in a kagome pattern is stable and resistant to damage or imperfections in the individual strips that make up the pattern, so too is this sensor only marginally affected by physical defects.

The sensor design has been tested and shown to work with helium, but could possibly be applied to other gases. More detail is available at ResearchGate, with some information about the math behind it all in a supplemental paper.

5K IMac Turned Into 5K Display

While Apple weren’t the first to invent high-DPI displays or to put them into consumer electronics, they did popularize them fairly effectively with the Retina displays in the early 2010s and made a huge number of them in the following years. The computers they’re attached to are getting up there in age, though, and although these displays are still functional it isn’t quite as straightforward to use them outside of their Apple-approved use. [David] demonstrates one way of getting this done by turning a 5k iMac into an external monitor.

The first attempt at getting a usable monitor from the old iMac was something called a Luna Display, but this didn’t have a satisfying latency. Instead, [David] turned to replacing the LCD driver board with a model called the R1811. This one had a number of problems including uneven backlighting, so he tried a second, less expensive board called the T18. This one only has 8-bit color instead of the 10-bit supported by the R1811 but [David] couldn’t personally tell the difference, and since it solved the other issues with the R1811 he went with this one. After mounting the new driver board and routing all of the wires, he also replaced the webcam with an external Logitech model and upgraded the speakers as well.

Even when counting the costs for both driver boards, the bill for this conversion comes in well under the cost of a new monitor of comparable quality from Apple, a company less concerned about innovation these days than overcharging their (admittedly willing) customers. For just a bit of effort, though, these older iMacs and other similar Apple machines with 5k displays can be repurposed to something relatively modern and still usable. Others have done similar projects and funded the upgrades by selling off the old parts.

A small white work truck sitting on a faded road with trees in the background. In its bed is what looks like an enormous drill battery in an upside down position. The "battery" is black with red and yellow stripes. It has the words "125V, 500 Ah, 52 kWh" and "Mr. G's Workshop" emblazoned on the side.

Kei Truck Looks Like A Giant Power Tool

Kei trucks are very versatile vehicles, but their stock powerplant can leave a bit to be desired. If you need more power, why not try an electric conversion?

[Ron “Mr. G” Grosinger] is a high school auto shop and welding teacher who worked with his students to replace the 40 hp gas motor in this Daihatsu Hijet with the 127 hp of a Hyper 9 electric motor. The motor sits in the original engine bay under the cab and is mated to the stock transmission with a custom adapter plate made from plate steel for less than $150. We really appreciate how they left all the electronics exposed to see what makes the conversion tick.

The faux battery was made by a foam sculptor friend out of urethane foam shaped with a carving knife and then painted. It slides on a set of unistrut trolleys and reveals the 5 salvaged Tesla battery modules that power the vehicle. The fold down sides of the truck bed allow easy access to anything not already exposed if any tweaking is necessary.

We’ve seen a kei truck become a camper as well or an ebike powered with actual power tool batteries. If you’re thinking of your own electric conversion, which battery is best?

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FLOSS Weekly Episode 863: Opencast: That Code Is There For A Reason

This week Jonathan chats with Olaf Andreas Schulte and Lars Kiesow about Opencast, the video management system for education. What does Opencast let a school or university accomplish, how has that changed over the last decade, and what exciting new things are coming? Watch to find out!

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The RollerMouse Keyboard

I just love it when y’all send in your projects, so thanks, [Kai]! But were do I even begin with this one? Okay, so, first of all, you need to know that [Kai Ruhl] built an amazing split keyboard with plenty of keys for even someone like me. Be sure to check it out, because the build log is great reading.

A lovely split keyboard on a pair of rails that doubles as a mouse.
Image by [Kai Ruhl] via Land of Kain
But that wasn’t enough — a mousing solution was in order that didn’t require taking [Kai]’s hands off of the keyboard. And so, over the course of several months, the RollerMouse Keyboard came into being. That’s the creation you see here.

Essentially, this is an ortholinear split with a built-in roller bar mouse, which basically acts like a cylindrical trackball. There’s an outer pipe that slides left/right and rolls up and down, and this sits on a stationary inner rod. The actual mouse bit is from a Logitech M-BJ69 optical number.

[Kai] found it unpleasant to work the roller bar using thumbs, so mousing is done via the palm rests. You may find it somewhat unpolished with all that exposed wiring in the middle. But I don’t. I just worry about dust is all. And like, wires getting ripped out accidentally.

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A Keyboard For Anything, Without A Keyboard

There are many solutions for remote control keyboards, be they Bluetooth, infrared, or whatever else. Often they leave much to be desired, and come with distinctly underwhelming physical buttons. [konkop] has a solution to these woes we’ve not seen before, turning an ESP32-S3 into a USB HID keyboard with a web interface for typing and some physical keyboard macro buttons. Instead of typing on the thing, you connect to it via WiFi using your phone, tablet, or computer, and type into a web browser. Your typing is then relayed to the USB HID interface.

The full hardware and software for the design is in the GitHub repository. The macro buttons use Cherry MX keys, and are mapped by default to the common control sequences that most of us would find useful. The software uses Visual Studio Code, and PlatformIO.

We like this project, because it solves something we’ve all encountered at one time or another, and it does so in a novel way. Yes, typing on a smartphone screen can be just as annoying as doing so with a fiddly rubber keyboard, but at least many of us already have our smartphones to hand. Previous plug-in keyboard dongles haven’t reached this ease of use.