TechyMagThings

If you are an American of a certain age, you know the Soviet Union launched the first satellite, Sputnik, beating the United States to orbit. You might even remember ham radio operators tuning into the satellites beeping. But you probably haven’t heard much about the team that built the vehicle, the problems they had, or the clever design choices they made. [Hoog] has a video that details the birth of Sputnik. You can see the video below.

The original plan was to launch a massive space lab, but it proved too ambitious. Keep in mind that in the late 1950s, you didn’t have tiny computers, high-density power sources, or advanced materials, and no one really knew what to expect in the Earth orbit environment. Even the viability of radio from the ground to orbit wasn’t a given. But Sputnik’s 1-watt transmitter did the job.

The event was part of the International Geophysical Year, but despite the agreement of international cooperation, the backdrop of the Cold War made politicians in the United States incite fear among Americans that the “Reds” were able to fly something over the United States both undetected and unopposed. Secretly, the US was pleased, as it wanted to fly spy satellites over the USSR, and this paved the way, since it could hardly complain if the US did the same thing the Soviets had already done.

The whole thing started the space race, which eventually led to the moon landings. It seems impossible that Sputnik was only 69 years ago. That means 70 years ago, there were no manmade satellites orbiting the Earth.

Watching the video, we’d hoped for more details about the internals but there just wasn’t time. However, we’ve covered that before (the main link is dead, but the detail links are still very interesting). The IGY was, for the most part, a great international cooperation, although few of its accomplishments are as memorable as Sputnik.

When it comes to robots, few are as iconic as Robby. [Ogrinz Labs] has wanted to build one and even examined a real one up for auction to get high-res photos of it. He also combined his designs with some other open-source designs, and it looks good. He’s released his design as a Creative Commons-licensed set of STL files that you, in theory, could print. There are more details and instructions in the video below.

If you are looking for something quick to print for the weekend, this isn’t it. As you might expect, this is a lot to print. The creator admits, too, that it isn’t totally accurate. It has bigger feet, for example, so his feet can fit inside. There are a few other modifications made for different reasons, but only a hard-core Robby enthusiast would notice any of them.

In theory, you can wear the robot as a costume, but at the current height, it doesn’t look like that will work for the creator. Also, the joints that would make things rotate are still forward work, but he’s promised to provide updates.

Robby started out on Forbidden Planet and went on to appear in many other movies and TV shows. Much of the original body was vacuum-formed plastic (an early form of ABS known as Royalite).

Thanks to modern slicers, you can easily print the parts on your printer for later assembly, and the video shows you how. You can select what connectors are used, and while we like the dovetail mode for most of what we do, Robby’s clean surfaces need dowel connectors. We would be really excited to see someone take these files and make a working robot based on the design.

We’ve been watching this project for a while. If you are sorry you missed the auction of the original, you aren’t alone. But we couldn’t have afforded the $5,375,000 price tag anyway.

For those of us old enough to remember the harrowing days of the early 2020s, alongside another major kerfuffle there was a complete breakdown in global supply chains that led to the 2020-2023 global chip shortage. Unsurprisingly, this pushed many hardware manufacturers into less orthodox approaches, massive BOM changes, and hurried redesigns. One of the results of this era found its way into the hands of the bloke over at the [Playduino] YouTube channel, who was mystified to find two bodge wires in his fancy Saleae logic analyzer.

The reason for popping open the LA was crosstalk between two channels, which was bad enough that it made the unit quite unusable for the intended task. After seeing the cut traces and bodge wires he initially assumed that since he bought it used that the previous owner had modified it, but said person denied having opened it since purchasing it from an official retailer.

This was when he emailed Saleae support to see whether they knew anything. Initially they denied knowing anything about such a modification, but then the CTO emailed back with a long and very detailed confession. As explained in the video, during the aforementioned chip crisis Saleae was forced to rapidly redesign their LAs to use whatever FPGAs and other parts they could still get their hands on.

An initial prototype unit passed their internal tests, so they had a first batch manufactured using PCBs from a different supplier. Despite sending the same Gerber files, the resulting PCBs had ground fill issues that necessitated the observed rework, but due to insufficient testing for crosstalk a total of 406 units made it into the wild.

Sadly he had to return the defective unit for a replacement, making it somewhat hard to let go of such a piece of history. That said, if you want to know whether you’re also one of the lucky remaining 405 LA owners, the CTO provided the affected serial number range: 00200026245 to 00200026675 are affected.

After recently reviewing a Wattcycle LFP battery sent over by the manufacturer, [Will Prowse] was made aware of some disturbing changes to the internals of batteries received by regular customers. Rather than the nice protected cables, thick solid metal busbars, braided wire and excellent build quality, the units that a regular customer – got as well as the one that [Will] bought off Amazon – all feature something more akin to what you’d find in a budget LFP battery, including a wide variety of LFP cells.

With these LFP batteries generally coming in fully opaque plastic cases, it’s really hard to tell what the internals look like without either going medieval on them or using less intrusive methods such as an X-ray machine. In this case less capable braided cables were replaced with regular cables that in a test showed a much higher voltage drop compared to the braided type.

Along with all the other changes between these batteries, this makes it impossible to rely on any reviews as a customer. [Will] notes that Wattcycle isn’t alone in doing this, and makes the case for more transparent cases for LFP batteries. After all, if you can see at a glance through the transparent case what the cables and wiring looks like, what BMS is installed and even what any LEDs on said BMS PCB are doing.

There are some LFP batteries with such a transparent case already, and with some smaller LFP batteries you can even pop the top off without having to resort to very permanent levels of violence, so this is not a problem without solutions. From a consumer perspective it definitely would be nice to see the internals as literal transparency from the manufacturer’s side, as well as an increased ability to monitor the battery for any thermal, leakage or other issues.

In that awkward transition phase between electromechanical accounting systems used in the 1940s and the introduction of fully digital computers we find systems such as the IBM 604 Electronic Calculator, advertised for accounting, calculating and engineering tasks. While not capable of complex instructions, loops and other advanced features, it did use an interesting modular architecture with easily swappable modules containing a vacuum tube and associated components. Recently [Ken Shirriff] took a poke at one of these and even powered it up.

This kind of pluggable system would become a staple of computer systems, as they enabled the use of modules or cards with specific functions that could be swapped and combined at will to increase system flexibility, lower costs and make repairs a snap. For the IBM 604 a total of about 1250 vacuum tubes were used, apparently all of which were found on these pluggable modules.

The module that [Ken] got his hands on has a thyratron tube, which is effectively a high current switch and rectifier. In the short demonstration video you can see it being used to switch a lamp on and off, with further details explained in the article.

Despite being rather limited in its functionality and limited by the punch card input and output speed, the IBM 604 was still a smashing commercial success with over 5600 units produced. A transistorized prototype version with 2200 transistors and 95% less power usage was created in 1954 that formed the basis for the IBM 608, the world’s first commercial all-transistorized calculator.

The 608 didn’t last too long, however, as at that point the breakneck pace of semiconductor technology meant that any newly released product was already obsolete by the time it hit the market. Despite this, fundamentals like pluggable modules would keep showing up over and over, ranging from the 1950s Bendix G-15 to even modern day systems, including PCs with pluggable RAM and expansion cards as well as mainframes where hot swapping of even entire CPU modules is just another feature.

One of the fun aspects of astrophysics is that much of it involves phenomena which you cannot exactly study from up close, with the supermassive black hole (SMBH) at the center of this galaxy – called Sagittarius A* (Sgr A) – being a great example. Although it’s been predicted since 1971 that black holes like Sgr A radiate energy which then pushes away nearby matter to create something akin to solar wind, this had so far not been proven. Now astronomers have discovered evidence for this emanating from Sgr A*.

Using five years worth of observations made with the Atacama Large Millimeter/Submillimeter Array (ALMA) and correlating it with other observations, a Southern Lobe of movement was identified, along with evidence for a Northern Lobe. Unlike a star where you are dealing with relatively massive quantities of matter being hurled into space, in the case of a very quiet SMBH like Sqr A* you are talking about occasional small wisps of gas of which a fraction gets turned into the radiation that then exerts pressure on the remaining gas.

It is speculated to be exactly this quiescent nature of Sgr A* that makes it so difficult to find evidence of SMBH wind, though one could also argue that having a well-fed SMBH whose event horizon rapidly expands would be fascinating from an astrophysics perspective, but less exciting for any nearby inhabited planets.

There are plenty of ways to get sound into your house: good old fashioned headphones, the Dolby surround setup we all lusted after back in the day, or the 21st century’s ubiquitous soundbar, with its ‘spatial audio’ magic. Which will work in your space? If you were an audio engineer, you’d set up listening area and use a microphone to map the space– but that would be thousands of points and sounds like tedium. [PlasmatronX] had a better idea: use Schlieren imaging to see the sound waves as the travel through the space. Schlieren imaging has trouble with audio frequencies, though, and imaging the entire living room was going to be difficult. So he scaled it all down– including the sound waves, by shifting to ultrasonic frequencies.

He’s using the usual mirror-and-razor Schlieren setup with an 8″ telescope mirror– and if you don’t know what that is, we did a deep dive on this kind of optical flow visualizer a while back. Inside the circular imaging area where that lets him see density changes, he’s set up what he calls a CAT– Computer Acoustic Tomography– array. It’s a rig on a turntable he can set up ultrasonic transducers on, to match the various speaker setups he wants to test, and turn so he can see from all angles what the scaled-down waves are doing. To capture those waves, which aren’t going to be standing still, he adds a stroboscope. All the ultrasound signals are being generated by a Pi Pico, and are scaled 4:1 in the frequency domain– that is, a high 10kHz whine becomes inaudible 40kHz. Those signals are fed through a DIY 8-channel amp into both ultrasonic transducers and larger ‘cat-repellent speakers’ from AliExpress.

The microcontroller is actually a Pico 2W, which is using its “W” to communicate via Bluetooth with a Pi 4. That SBC is running the camera, the stepper for the turntable, and image processing, along with the timing for the audio signals. After that it’s a matter of setting up a scaled down 7.1 surround setup and itty-bity soundbar, and test it on a (stuffed) guinea pig. Obviously you can see a big difference between the steered beams from the tiny soundbar and the true surround, but how that translates to listening pleasure will be at least somewhat subjective.

What’s less subjective is the obvious effect soft furnishings add to the simulation. Now he doesn’t take the time to find a material that will scale the frequency response of a set of curtains, but we’re not sure how much that matters. At 5kHz or 20kHz, they’re going to deaden sound, and you can see that here, and you can see it’s a much bigger deal for the shaped beams of the soundbar than it is for surround sound. In the end, [PlasmatronX] decides to stick to headphones, but the whole video is very much worth watching, so we’ve embeddded it below. If you want to try it yourself he’s put his code on GitHub.

Thanks to [PlasmatronX] for the tip!