ice fishing tent and antenna in a snowy field

Ice Fishing Tent Makes Winter Ham Radio Comfy

March 12, 2022 by Donald Papp 29 Comments

Cross-pollination between different activities and industries can yield some pretty useful techniques or product combinations, and [Steve] shares some details on using ice fishing gear to make winter ham radio activities more comfortable and portable.

With the help of a folding tent shelter, [Steve] was able to create a minimal and self-contained field station that hosted all his needed equipment, and with the help of a small propane heater, stayed quite comfortable during a 24 hour winter event.

For those interested in the radio end of what [Steve] was doing, he goes into detail about the radio equipment and antenna he used, which itself stows easily into a bag and withstood high winds with success. The goal of the event after all was emergency preparedness, and while radio can operate without a wider infrastructure to support it, antenna design is crucial for best results.

As for keeping the operator safe and sound during all this, it turns out that the problem of a pop-up winter shelter that is both light and compact has already been solved by ice fishers; and while it can be fun to roll one’s own solutions, there’s not always a need to re-invent the wheel.

How To Make Laser-cut Decals On The Cheap

March 12, 2022 by Donald Papp 13 Comments

Want to make a sweet adhesive decal with a complex design and floating elements, but all you have is a laser cutter and some tape? Good news, because that’s all you need with this method of creating adhesive tape decals on a laser cutter demonstrated by the folks at [Lasers Over Los Angeles]. The overall technique is very similar to creating vinyl decals and using tape transfer to apply them, but is geared towards laser cutters and nice, cheap tape.

This method also makes applying to non-flat surfaces a breeze.

The way it works is this: paper-based tape (such as blue painter’s tape) is laid down in strips on the laser cutter’s honeycomb bed, forming a nice big rectangle big enough for the intended design. Then, the laser cutter cuts vector art into the tape, resulting in an adhesive decal ready to be stuck to some other surface. Transferring is done by using good quality clear packing tape to “pick up” the decal, then move it to where it needs to be.

To do this, one lays strips of packing tape onto the top of the design on the laser bed, then lifts the design up and away. Move the design to its destination (the clear packing tape helps in eyeballing the final position), press the decal onto the final surface, and carefully peel away the clear packing tape. This works because the packing tape sticks only weakly to the back of the painter’s tape; it’s a strong enough bond to hold the decal, but weak enough that the decal will stick to a surface even better.

It’s true that painter’s tape isn’t as durable as vinyl and the color selection is a bit limited, but design-wise one can go as big as the laser bed allows, and the price is certainly right. Plus it’s easily cut by even the most anemic of diode lasers.

Speaking of desktop vinyl cutters, they may have small working areas compared to most laser cutters, but they have some fantastic workshop applications. They can even do home PCB fabrication, by way of knocking out three essential pieces: the etching mask, solder mask, and solder stencil.

Vintage Meter Repair? It’s Easier With X-Rays

March 6, 2022 by Donald Papp 18 Comments

Here’s an interesting and detailed teardown and repair of a Keithley 2001 7.5 Digit multimeter that is positively dripping with detail. It’s also not every day that we get to see someone using x-ray imaging to evaluate the extent of PCB damage caused by failed electrolytic capacitors.

Dark area is evidence of damage in the multi-layer PCB.

Sadly, this particular model is especially subject to that exact vintage electronics issue: electrolytic capacitor failure and leakage. These failures can lead to destroyed traces, and this particular unit had a number of them (in addition to a few destroyed diodes, just for good measure.) That’s where the x-ray machine comes in handy, because some of the damage is hidden inside the multi-layer PCBs.

[Shahriar], perhaps best known as [The Signal Path], narrates the entire process of fixing up the high-quality benchtop multimeter in a video, embedded below (or you can skip directly to the x-ray machine being broken out.) [Shahriar] was able to repair the device, thanks in part to it being in relatively good shape, and having the right tools available. Older electronics are not always so cooperative; the older a device is, the more likely one is to run into physical and logical standards that no longer exist.

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How To Solder To Aluminum, Easily

March 6, 2022 by Donald Papp 53 Comments

[Ted Yapo] shared a method of easily and conveniently soldering to aluminum, which depends on a little prep work to end up only slightly more complex than soldering to copper. A typical way to make a reliable electrical connection to aluminum is to use a screw and a wire, but [Ted] shows that it can also be done with the help of an abrasive and mineral oil.

Aluminum doesn’t solder well, and that’s because of the oxide layer that rapidly forms on the surface. [Ted]’s solution is to scour the aluminum with some mineral oil. The goal is to scrape away the oxide layer on the aluminum’s surface, while the mineral oil’s coating action prevents a new oxide layer from immediately re-forming.

After this prep, [Ted] uses a hot soldering iron and a blob of solder, heating it until it sticks. A fair bit of heat is usually needed, because aluminum is a great heat conductor and tends to be lot thicker than a typical copper ground plane. But once the aluminum is successfully tinned, just about anything can be soldered to it in a familiar way.

[Ted] does caution that mineral oil can ignite around 260 °C (500 °F), so a plan should be in place when using this method, just in case the small amount of oil catches fire.

This looks like a simple technique worth remembering, and it seems easier than soldering by chemically depositing copper onto aluminum.

Hardware Hacking 101 Needs Matching Toolkit

March 3, 2022 by Donald Papp 21 Comments

One doesn’t always have the luxury of sipping tea comfortably while hacking a piece of hardware at a fully-equipped workbench, where every tool is within reach. To address this, [Zokol] shares an early look at a hardware hacking toolkit-in-progress, whose purpose is to make hacking sessions as productive as possible while keeping size and weight within reasonable limits. There isn’t a part list yet, but there are some good tips on creating your own.

To put together an effective hardware hacking toolkit, one must carefully consider what kinds of tasks need to be performed, and in what order. Once a basic workflow is identified, one can put together a set of complementary hardware tools and resources to meet the expected needs. The goal is to have the tools to go as far as one can in a single session, and identify any specialized equipment that will be needed later. That way, follow-up sessions can be as effective as possible.

Since hardware hacking is all about inspecting (and possibly modifying the behavior of) electronic devices, [Zokol] observes that step one is always to begin with external interfaces. That means common cables and adapters should all be part of a hardware hacking toolkit, otherwise the session might end awfully early. The next step is to open the device, so common tools and ways to deal with things like adhesives are needed. After that, diagnostic tools like multimeters come into play, with tools becoming more specialized as investigation proceeds. It’s a very sensible way to approach the problem of what to bring (and not bring) in a hardware hacking toolkit, and we can’t wait to see what the final version looks like.

Hardware hacking sometimes involves hardware that can’t be opened without damaging it. The Google Stadia controller is one such piece of hardware, and [Zokol] addressed the problem of how to permanently disable the microphone by figuring out exactly where to drill a hole.

Row of white 3D printed shoes in different styles

CAD Up Some Shoes, But Don’t Start From Scratch

March 3, 2022 by Donald Papp 14 Comments

Nothing helps a project get off the ground better than a good set of resources, and that’s what led [DaveMakesStuff] to release his Digital Shoe Design Kit, which is a set of 3D models ready to customize into a basic running shoe.

This is exactly what is needed for people who are interested in designing a custom shoe, but perhaps not interested in modeling every element entirely from scratch. [DaveMakesStuff]’s resources allows one to mix outsoles, midsoles, uppers, and other basic shoe elements into a finished model, ready to be resized or even 3D printed if desired. The files are all in stl format, but resizing stl files is trivial, and more advanced editing is possible with mesh sculpting programs like Blender.

If the gears in your head are starting to turn and you are wondering whether it is feasible to 3D scan your feet for some experiments in DIY custom footwear, take a few minutes and read up on 3D scanning and what to expect from the process to hit the ground running.

Review: DevTerm Linux Handheld Has Retro-Future Vibe

March 2, 2022 by Donald Papp 32 Comments

It’s not every day that an open-source, portable Linux handheld computer gets announced, so I couldn’t resist placing an order for the DevTerm by ClockworkPi back when we first learned about the stylish little terminal, which includes a 1280 x 480 screen (double-wide VGA) and a modular little thermal printer.

Of course, the global semiconductor shortage combined with shipping slowdowns led to delays, but things did ultimately come together for the project. I’ve always been a sucker for small-format machines, especially ones that come as a well-designed kit, and that means I can tell you all about what it was like to put it together and turn it on. There’s a lot to look at, so let’s get started.

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