Year: 2025

SkyRoof, A New Satellite Tracker For Hams

June 10, 2025 by No comments

Communicating with space-based ham radio satellites might sound like it’s something that takes a lot of money, but in reality it’s one of the more accessible aspects of the hobby. Generally all that’s needed is a five-watt handheld transceiver and a directional antenna. Like most things in the ham radio world, though, it takes a certain amount of skill which can’t be easily purchased. Most hams using satellites like these will rely on some software to help track them, which is where this new program from [Alex Shovkoplyas] comes in.

The open source application is called SkyRoof and provides a number of layers of information about satellites aggregated into a single information feed. A waterfall diagram is central to the display, with not only the satellite communications shown on the plot but information about the satellites themselves. From there the user can choose between a number of other layers of information about the satellites including their current paths, future path prediction, and a few different ways of displaying all of this information. The software also interfaces with radios via CAT control, and can even automatically correct for the Doppler shift that is so often found in satellite radio communications.

For any ham actively engaged in satellite tracking or space-based repeater communications, this tool is certainly worth trying out. Unfortunately, it’s only available for Windows currently. For those not looking to operate under Microsoft’s thumb, projects such as DragonOS do a good job of collecting up the must-have Linux programs for hams and other radio enthusiasts.

Is The Atomic Outboard An Idea Whose Time Has Come?

June 10, 2025 by 7 Comments

Everyone these days wants to talk about Small Modular Reactors (SMRs) when it comes to nuclear power. The industry seems to have pinned its hopes for a ‘nuclear renaissance’ on the exciting new concept. Exciting as it may be, it is not exactly new: small reactors date back to the heyday of the atomic era. There were a few prototypes, and a lot more paper projects that are easy to sneer at today. One in particular caught our eye, in a write-up from Steve Wientz, that is described as an atomic outboard motor.

It started as an outgrowth from General Electric’s 1950s work on airborne nuclear reactors. GE’s proposal just screams “1950s” — a refractory, air-cooled reactor serving as the heat source for a large turboprop engine. Yes, complete with open-loop cooling. Those obviously didn’t fly (pun intended, as always) but to try and recoup some of their investment GE proposed a slew of applications for this small, reactor-driven gas turbine. Rather than continue to push the idea of connecting it to a turboprop and spew potentially-radioactive exhaust directly into the atmosphere, GE proposed podding up the reactor with a closed-cycle gas turbine into one small, hermetically sealed-module. Continue reading “Is The Atomic Outboard An Idea Whose Time Has Come?” →

The Ongoing BcacheFS Filesystem Stability Controversy

June 10, 2025 by 19 Comments

In a saga that brings to mind the hype and incidents with ReiserFS, [SavvyNik] takes us through the latest data corruption bug report and developer updates regarding the BcacheFS filesystem in the Linux kernel. Based on the bcache (block cache) cache mechanism in the Linux kernel, its author [Kent Overstreet] developed it into what is now known as BcacheFS, with it being announced in 2015 and subsequently merged into the Linux kernel (6.7) in early 2024. As a modern copy-on-write (COW) filesystem along the lines of ZFS and btfs, it was supposed to compete directly with these filesystems.

Despite this, it has become clear that BcacheFS is rather unstable, with frequent and extensive patches being submitted to the point where [Linus Torvalds] in August of last year pushed back against it, as well as expressing regret for merging BcacheFS into mainline Linux. As covered in the video, [Kent] has pushed users reporting issues to upgrade to the latest Linux kernel to get critical fixes, which really reinforces the notion that BcacheFS is at best an experimental Alpha-level filesystem implementation and should probably not be used with important data or systems.

Although one can speculate on the reasons for BcacheFS spiraling out of control like this, ultimately if you want a reliable COW filesystem in Linux, you are best off using btrfs or ZFS. Of course, regardless of which filesystem you use, always make multiple backups, test them regularly and stay away from shiny new things on production systems.

Continue reading “The Ongoing BcacheFS Filesystem Stability Controversy” →

Repairing Vintage Sony Luggable Calculators

June 10, 2025 by No comments

You might wonder why you’d repair a calculator when you can pick up a new one for a buck. [Tech Tangents] though has some old Sony calculators that used Nixie tubes, including one from the 1960s. Two of his recent finds of Sony SOBAX calculators need repair, and we think you’ll agree that restoring these historical calculators is well worth the effort. Does your calculator have a carrying handle? We didn’t think so. Check out the video below to see what that looks like.

The devices don’t even use modern ICs. Inside, there are modules of discrete parts encapsulated in epoxy. There isn’t even RAM inside, but there is a delay line memory, although it is marked “unrepairable.”

There is some interesting history about this line of calculators, and the video covers that. Apparently, the whole line of early calculators grew out of an engineer’s personal project to use transistors that were scrapped because they didn’t meet the specifications for whatever application that used them.

The handle isn’t just cosmetic. You could get an external battery pack if you really wanted a very heavy — about 14 pounds (6.3 kilograms) — and large portable calculator. We are sure the $1,000 retail price tag didn’t include a battery.

These machines are beautiful, and it is fun to see the construction of these old devices. You might think our favorite calculator is based on Star Trek. As much as we do like that, we still think the HP-41C might be the best calculator ever made, even in emulation.

Continue reading “Repairing Vintage Sony Luggable Calculators” →

Origami assembly line.

Building An Assembly Line For Origami Pigeons

June 9, 2025 by 6 Comments

When it comes to hacks, the best ones go to extremes. Either beautiful in their simplicity, or magnificent in their excess. And, well, today’s hack is the latter: excessive. [HTX Studio] built an assembly line for origami pigeons!

One can imagine the planning process went something like this:

  1. Make origami pigeon assembly line
  2. ?
  3. Profit

But whatever the motivation, this is an impressive and obviously very well engineered machine. Even the lighting is well considered. It’s almost as if it were made for show…

Now, any self-respecting nerd should know the difference between throughput and latency. From what we could glean from the video, the latency through this assembly line is in the order of 50 seconds. Conservatively it could probably have say 5 birds in progress at a time. So let’s say every 10 seconds we have one origami pigeon off the assembly line. This is a machine and not a person so it can operate twenty four hours a day, save downtime for repairs and maintenance, call it 20 hours per day. We could probably expect more than 7,000 paper pigeons out of this machine every day. Let’s hope they’ve got a buyer lined up for all these birds.

If you’re interested in assembly lines maybe we could interest you in a 6DOF robotic arm, or if the origami is what caught your eye, check out the illuminating, tubular, or self-folding kind!

Continue reading “Building An Assembly Line For Origami Pigeons” →

Saving Green Books From Poison Paranoia

June 9, 2025 by 17 Comments

You probably do not need us to tell you that Arsenic is not healthy stuff. This wasn’t always such common knowledge, as for a time in the 19th century a chemical variously known as Paris or Emerald Green, but known to chemists as copper(II) acetoarsenite was a very popular green pigment. While this pigment is obviously not deadly on-contact, given that it’s taken 200 years to raise the alarm about these books (and it used to be used in candy (!)), arsenic is really not something you want in your system. Libraries around the world have been quarantining vintage green books ̶f̶o̶r̶ ̶f̶e̶a̶r̶ ̶b̶i̶b̶l̶i̶o̶p̶h̶i̶l̶i̶es ̶m̶i̶g̶h̶t̶ ̶b̶e̶ ̶t̶e̶m̶p̶t̶e̶d̶ ̶t̶o̶ ̶l̶i̶c̶k̶ ̶t̶h̶e̶m̶  out of an abundance of caution, but researchers at The University of St. Andrews have found a cheaper method to detect the poison pigment than XRF or Raman Spectroscopy previously employed.

The hack is simple, and in retrospect, rather obvious: using a a hand-held vis-IR spectrometer normally used by geologists for mineral ID, they analyzed the spectrum of the compound on book covers. (As an aside, Emerald Green is similar in both arsenic content and color to the mineral conichalcite, which you also should not lick.)  The striking green colour obviously has a strong response in the green range of the spectrum, but other green pigments can as well. A second band in the near-infrared clinches the identification.

A custom solution was then developed, which sadly does not seem to have been documented as of yet. From the press release it sounds like they are using LEDs and photodetectors for color detection in the green and IR at least, but there might be more to it, like a hacked version of common colour sensors that put filters on the photodetectors.

While toxic books will still remain under lock and key, the hope is that with quick and easy identification tens of thousands of currently-quarantined texts that use safer green pigments can be returned to circulation.

Tip of the hat to [Jamie] for the tip off, via the BBC.

Two white, cylindrical speakers are shown. The sides and most of the tops of the speakers are covered in holes, and at the center of the top of each, there is a circular LCD display. The top of the speaker is marked “Braun.”

A Modern Take On Iconic Industrial Design

June 9, 2025 by 12 Comments

The Functionalist design philosophy that Dieter Rams brought to Braun from the 50s to the 90s still inspires the look of a few devices, including Apple’s iPod, Teenage Engineer’s synthesizers and recorders – and [2dom]’s IR7 streaming radio.

The streaming radio was inspired by Braun’s portable radios, particularly the SK2, TP1, and the T3 pocket radio. [2dom] started with the T3’s circular pattern of holes and experimented with several variations, finally settling on a cylindrical shape with a central display; a prototype with a low-power monochrome rectangular display was eventually rejected in favor of a circular LCD. The housing consists of four 3D-printed components: an upper and lower shell, a resonator for the speaker, and a knob for a rotary encoder.

Electronics-wise, an ESP32 handles the computing requirements, while the LCD and rotary encoder provide a user interface. For audio, it uses a VS1053 MP3 decoder, PAM8403 amplifier, and a wideband speaker, with an audio isolation transformer to clean up the audio. To reduce power consumption, a MOSFET cuts power to the peripheral components whenever the device is in sleep mode. The full design is available on GitHub.

The end result of this effort is a quite authentic-looking 21st-century adaptation of Rams’s original designs. If you’re interested in more Braun designs, check out this replica of one of their desk fans. We’ve also seen a restoration of one of Braun’s larger radios, the TS2.