[MIKROWAVE1] claims he’s not a radio repair guy, but he agreed to look at a malfunctioning Hallicrafters S-120 shortwave receiver. He lets us watch as he tries to get it in shape in the video below. You’ll see that one of his subscribers had done a great job restoring the radio, but it just didn’t work well.
Everything looked great including the restored parts, so it was a mystery why things wouldn’t work. However, every voltage measured was about 20V too low. Turns out that the series fuse resistor had changed value and was dropping too much voltage.
It is common these days to have a soldering iron where you can set the temperature using some sort of digital control. But how accurate is it? Probably pretty accurate, but [TheHWCave] picked up a vintage instrument on eBay that was made to read soldering iron temperature. You can see the video below, which includes an underwhelming teardown.
The device is a J thermocouple and a decidedly vintage analog meter. What’s inside? Nearly nothing. So why did the meter not read correctly? And where is the cold junction compensation?
While version control used to be reserved for big corporate projects, it is very mainstream these days. You can attribute much of that to Git, the software that has nearly displaced other version control. Git works well, it is versatile, and it scales well. It is easy to use as an individual developer or as part of a worldwide team. But Git is also one of those things that people don’t always study, they just sort of “pick it up” as they go. That motivated [Glasskube] to create “The Guide to Git I Never Had.”
If you are ready to click away because you are not a software person, hang on. Git is actually useful for many different kinds of data, and there are a number of hardware projects that use Git in some form. That’s especially true if the project has some code associated with it, but there are projects that consist of PCBs, reverse engineering documentation, or schematics.
Elliot Williams is back from vacation, and he and Al Williams got together to talk about the best Hackaday posts from the last week. Of course, the Raspberry Pi RP2350 problem generated a bit of discussion.
On a lighter note, they saw laser lawn care, rooting WiFi devices, and some very black material made from wood. Need more current-sinking capability from a 555? They talked about that, too, along with a keyboard you use with your feet.
The guys had a lot to say about Klipper, why you might want to move your 3D printer to it, and the FCC’s stance on ham radio antennas in restricted neighborhoods. Oh, and don’t forget to play “What’s that Sound?”
When you think of Sony, you probably think of a technology company that’s been around forever. However, as [Asianometry] points out, it really formed in the tough years after World War II. The two people behind the company’s formation were an interesting pair. One of them was a visionary engineer and one was a consummate businessman.
While it is hard to imagine today, securing a license to produce transistors was difficult in the early days. What’s worse is, even with the license, it was not feasible to use the crude devices in a radio.
[Peter Demchenko] wanted to use a low power TS555 in an ESR meter design. The problem is, he needed to handle significant current sink requirements for cases where the capacitor under test had a low ESR. The TS555 wasn’t up to the task.
However, [Peter] made an interesting observation. the output pin of the device can sink or source current. However, the discharge pin is exactly the same output but can only sink current.
But what if you tied them together? Using some equalizing resistors, that’s exactly what he did, and this roughly doubles the rated current sink capability. According to [Peter], you do make the circuit more sensitive to power supply variations, but that could be an acceptable trade, depending on your application.
Last time I tried to convince you that, if you haven’t already, you should try running your 3D printer with Klipper. There are several ways to actually make it work.
The first thing you need is something to run the Klipper host. Most people use a Raspberry Pi and if you already have one that runs OctoPrint, for example, you might well use it. Just tuck your SD card away in case you give up and install a fresh Linux system on a new card.
The Creality Sonic Pad has issues, but it does work.
However, a Pi isn’t your only option. You should be able to make it work on nearly anything that runs Linux. We’ve even seen it running on Windows under WSL. If you have an old laptop that can run Linux, that would work, too. We’ve even heard it works on a Chromebook.
The other option is to get a “pad.” Several vendors make touchscreens with some Linux single-board computer bundled together with Klipper preinstalled. For example, there is the Creality Sonic Pad, along with similar devices from other 3D printing companies.
If you decide to go that route, you might want to make sure it is easy to install your own software easily. Some pads, like the Creality unit, are notorious for having so much customization that they don’t lend themselves to upgrades unless they come from the manufacturer. In some cases, you can wipe out the stock firmware and install a normal operating system, but at that point, you could probably just buy a Pi and a touchscreen, right?
