Bakelite To The Future – A 1950s Bluetooth Headset

A decade ago, [Jouke Waleson] bought a Dutch ‘model 1950’ PTT (The Dutch Postal Service) rotary-dial telephone of presumably 1950s vintage manufactured by a company called Standard Electric, and decided it would be neat to hack it to function as a Bluetooth hands-free device. Looking at the reverse, however, it is stamped “10.65” on the bottom, so maybe it was made as recently as 1965, but whatever, it’s still pretty old-tech now.

A well-specified transformer?

The plan was to utilise ESP32 hardware with the Espressif HFP stack to do all the Bluetooth heavy lifting. [Jouke] did find out the hard way that this is not a commonly-trodden path in hackerland, and working examples and documentation were sparse, but the fine folks from Espressif were on hand via GitHub to give him the help he needed. After ripping into the unit, it was surprisingly stuffed inside there. Obviously, all the switching, even the indication, was purely electromechanical, which should be no surprise. [Jouke] identified all the necessary major components, adding wires and interfacing components as required, but was a bit stumped at the function of one funky-looking component that we reckon must be a multi-tap audio transformer, oddly finished in baby pink! After renovating some interesting cross-shaped mechanical indicators and wiring up some driving transistors, it was time to get on to the audio interface. Continue reading “Bakelite To The Future – A 1950s Bluetooth Headset”

Small Volumetric Lamp Spins At 6000 RPM

Volumetric displays are simply cool. Throw some LEDs together, take advantage of persistence of vision, and you’ve really got something. [Nick Electronics] shows us how its done with his neat little volumetric lamp build.

The concept is simple. [Nick] built a little device to spin a little rectangular array of LEDs. A small motor in the base provides the requisite rotational motion at a speed of roughly 6000 rpm. To get power to the LEDs while they’re spinning, the build relies on wire coils for power transmission, instead of the more traditional technique of using slip rings.

The build doesn’t do anything particularly fancy—it just turns on the whole LED array and spins it. That’s why it’s a lamp, rather than any sort of special volumetric display. Still, the visual effect is nice. We’ve seen some other highly capable volumetric displays before, though. Video after the break.
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3D Printing With A Hot Glue Gun

Face it, we’ve all at some time or other looked at our hot glue guns, and thought “I wonder if I could use that for 3D printing!”. [Proper Printing] didn’t just think it, he’s made a working hot glue 3D printer. As you’d expect, it’s the extruder which forms the hack here.

A Dremel hot glue gun supplies the hot end, whose mains heater cartridge is replaced with a low voltage one with he help of a piece of brass tube. He already has his own design for an extruder for larger diameters, so he mates this with the hot end. Finally the nozzle is tapped with a thread to fit an airbrush nozzle for printing, and he’s ready tp print. With a much lower temperature and an unheated bed it extrudes, but it takes multiple attempts and several redesigns of the mechanical parts of the extruder before he finally ended up with the plastic shell of the glue gun as part of the assembly.

The last touch is a glue stick magazine that drops new sticks into a funnel on top of the extruder, and it’s printing a Benchy. At this point you might be asking why go to all this effort, but when you consider that there are other interesting materials which are only available in stick form it’s clear that this goes beyond the glue. If you’re up for more hot glue gun oddities meanwhile, in the past we’ve shown you the opposite process to this one.

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Supercon 2024 Flower SAO Badge Redrawing In KiCad

Out of curiosity, I redrew the Supercon Vectorscope badge schematics in KiCad last year. As you might suspect, going from PCB to schematic is opposite to the normal design flow of KiCad and most other PCB design tools. As a result, the schematics and PCB of the Vectorscope project were not really linked. I decided to try it again this year, but with the added goal of making a complete KiCad project. As usual, [Voja] provided a well drawn schematic diagram in PDF and CorelDRAW formats, and a PCB design using Altium’s Circuit Maker format (CSPcbDoc file). And for reference, this year I’m using KiCad v8 versus v7 last year.

Importing into KiCad

This went smoothly. KiCad imports Altium files, as I discovered last year. Converting the graphic lines to traces was easier than before, since the graphical lines are deleted in the conversion process. There was a file organizational quirk, however. I made a new, empty project and imported the Circuit Maker PCB file. It wasn’t obvious at first, but the importing action didn’t make use the new project I had just made. Instead, it created a completely new project in the directory holding the imported Circuit Maker file. This caused a lot of head scratching when I was editing the symbol and footprint library table files, and couldn’t figure out why my edits weren’t being seen by KiCad.  I’m not sure what the logic of this is, was an easy fix once you know what’s going on. I simply copied everything from the imported project and pasted it in my new, empty project. Continue reading “Supercon 2024 Flower SAO Badge Redrawing In KiCad”

A Look Inside A Canadian Satellite TV Facility

If you’ve ever wondered what goes on in the ground facilities of a satellite TV operation, you could go banging on the doors or your local station. You’d probably get thrown out in short order. Alternatively, you could watch this neat little tour from [saveitforparts].

The tour takes us through a ground facility operated by the Canadian Broadcasting Corporation and Radio Canada in Montreal. The facility in question largely handles CBC’s French language content for the Canadian audience. We’re treated to a look at the big satellite dishes on the roof, as well as the command center inside. Wall to wall screens and control panels are the order of the day, managing uplinks and downlinks and ensuring content gets where it needs to go. Particularly interesting is the look at the hardcore hardware for full-strength transmission to satellites. The video also includes some neat trivia, like how CBC was the first broadcaster to offer direct satellite TV to customers in 1978.

We’ve seen [saveitforparts] tackle some interesting satellite hardware teardowns before, too.

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Voyager 1 Fault Forces Switch To S-Band

We hate to admit it, but whenever we see an article about either Voyager spacecraft, our thoughts immediately turn to worst-case scenarios. One of these days, we’ll be forced to write obituaries for the plucky interstellar travelers, but today is not that day, even with news of yet another issue aboard Voyager 1 that threatens its ability to communicate with Earth.

According to NASA, the current problem began on October 16 when controllers sent a command to turn on one of the spacecraft’s heaters. Voyager 1, nearly a light-day distant from Earth, failed to respond as expected 46 hours later. After some searching, controllers picked up the spacecraft’s X-band downlink signal but at a much lower power than expected. This indicated that the spacecraft had gone into fault protection mode, likely in response to the command to turn on the heater. A day later, Voyager 1 stopped communicating altogether, suggesting that further fault protection trips disabled the powerful X-band transmitter and switched to the lower-powered S-band downlink.

This was potentially mission-ending; the S-band downlink had last been used in 1981 when the probe was still well within the confines of the solar system, and the fear was that the Deep Space Network would not be able to find the weak signal. But find it they did, and on October 22 they sent a command to confirm S-band communications. At this point, controllers can still receive engineering data and command the craft, but it remains to be seen what can be done to restore full communications. They haven’t tried to turn the X-band transmitter back on yet, wisely preferring to further evaluate what caused the fault protection error that kicked this whole thing off before committing to a step like that.

Following Voyager news these days feels a little morbid, like a death watch on an aging celebrity. Here’s hoping that this story turns out to have a happy ending and that we can push the inevitable off for another few years. While we wait, if you want to know a little more about the Voyager comms system, we’ve got a deep dive that should get you going.

Thanks to [Mark Stevens] for the tip.

Bogey Six O’clock!: The AN/APS-13 Tail Warning Radar

Although we think of air-to-air radar as a relatively modern invention, it first made its appearance in WWII. Some late war fighters featured the AN/APS-13 Tail Warning Radar to alert the pilot when an enemy fighter was on his tail. In [WWII US Bombers]’ fascinating video we get a deep dive into this fascinating piece of tech that likely saved many allied pilots’ lives.

Fitted to aircraft like the P-51 Mustang and P-47 Thunderbolt, the AN/APS-13 warns the pilot with a light or bell if the aircraft comes within 800 yards from his rear. The system consisted of a 3-element Yagi antenna on the vertical stabilizer, a 410 Mhz transceiver in the fuselage, and a simple control panel with a warning light and bell in the cockpit.

In a dogfight, this allows the pilot to focus on what’s in front of him, as well as helping him determine if he has gotten rid of a pursuer. Since it could not identify the source of the reflection, it would also trigger on friendly aircraft, jettisoned wing tanks, passing flak, and the ground. This last part ended up being useful for safely descending through low-altitude clouds.

This little side effect turned out to have very significant consequences. The nuclear bombs used on Hiroshima and Nagasaki each carried four radar altimeters derived from the AN/APS-13 system.

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