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Going Whole-Hog on a First Satellite Ground Station

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When most radio enthusiasts start trying to pick up signals from satellites, they might put together a quick-and-dirty Yagi antenna and try to catch a repeater as is passes overhead, or they might grab a small unused dish from a satellite TV service and point it up at a weather satellite by hand to try to decode some of the data coming down. But [Cranktown City] had a different approach. He found an eight-foot dish online and built a massive articulating base station out of it as his first exploration into the world of satellites. The first problem that needs to be solved with a dish of this size is its mounting location. This installation uses a large post and concrete foundation with a custom-fabricated metal base at the bottom. The metal base houses all of the electronics not just for receiving signals from the dish, but also for orienting it properly. That includes a large metal gear driven by a wheelchair motor to control its azimuth and a linear actuator to take care of its ele...
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NASA’s Lunar Grounding Challenge is a Real Buzz

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One could make a joke about how an astronaut walking on the lunar surface is rather akin to a cat walking on the carpet in the living room, but out in space the resulting triboelectric discharge can do a lot more damage than just some stinging fingers and a bemused looking cat. The problem that NASA and other space agencies are dealing with is that the charge that builds up on a lunar-walking astronaut is very hard to equalize with something like a lunar lander. For this reason they have now set up the Lunar Grounding Challenge to consult the public whilst dangling $150,000 of rewards in front of anyone ready to pounce with a good idea. Here on Earth we got many ways in which we can get rid of such an unwanted charge, with dry winter weather demonstrating quite effectively why humidity is a crucial factor here. With no real atmosphere on the Moon, each astronaut thus becomes a walking capacitor, which is worsened when said astronaut ventures outside of the sunlit areas and then ret...
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Making Photovoltaic Solar Cells with a Microwave

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Although solar panels may seem like a kind of magic, they’re really quite simple devices, in their silicon form featuring nothing but the p-type silicon wafer and an n-type layer doped with e.g. phosphorus. Because of this simplicity it’s quite possible to make your own solar cells at home using only a few basic, off-the-shelf ingredients and a kiln, which in this recent video by [Dr. Semiconductor] uses a microwave kiln and thus justifies the video’s title. Even the silicon wafer that you start with can be easily purchased online, though you have to be careful that it’s a bare wafer, without existing etchings on it. On this you need to get a phosphorus-rich layer, which is done by creating a delicious mixture of 1 mL of tetraethyl orthosilicate (TEOS), 0.3 mL of 85 wt% phosphoric acid, 5 mL of ethanol and 0.25 mL of distilled water. After low heat boiling this for 30 minutes, it is spincoated onto the cut square of silicon wafer using a spinning platform, like...
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An RV on a Bike

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Bicycles are the ultimate form of transportation freedom. They’re easy to repair, parts are cheap, and they will travel almost anywhere for free, as long as the rider has enough calories. Their only real downside is dealing with car-dependent societies, but once a year there’s a place in the American desert that eschews all of this and [Attoparsec] decided to take this custom cargo bike modified into an RV out to Burning Man , a place and time that would be perfect for a build like this. The build started out as a cargo bike, but not many of them have cargo areas long enough to support a sleeping human. To increase this storage capacity, the bed was extended towards the rear. Without moving the axle further back, though, this created a problem with tail-heaviness so two trailer jacks with wheels were added to the back to keep it from occasionally tipping up too far. The sleeping enclosure was built with rigid foam insulation and taped together, in a modified style common to...
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Meshtastic Sniffer for DragonOS

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Meshtastic has gained a lot of popularity over the last few years thanks to its low barrier of entry. No licenses are needed and the hardware is dirt cheap, at least when compared to a lot of ham radio gear. But while that physical barrier is low, there is a bit of a learning curve. Part of that comes from the fact that there are a lot of channels and modes that people could be communicating on, and unless the user knows that information up front it can be hard to find where the conversations are happening. [cemaxecuter] noticed this problem and built a Meshtastic sniffer into his radio-forward Linux distribution, DragonOS . The sniffing software is built in C and comes as a complete standalone binary and does not rely on GNU Radio. With DragonOS up and running and the software loaded, it can look at the entire bandwidth that Meshtastic operates on and detect any traffic and decode it (as long as the key is known). [cemaxecuter] is using a HackRF as a software-defined radio for this p...
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An Open Micro-Maniplulator Improved

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If you need a micro-manipulator, you probably already have a good idea of what it does. For example, you might be moving a probe over an IC die or wafer. You might be looking at something through a microscope. The key is moving something in very small, precise increments along three axes. An open-source design for a micro-manipulator has seen significant improvements lately. You can see several videos about the device below. The device uses stepper motors, parallel kinematics, and miniature ball joints to achieve precise motion. The recent version 4.0 update fixes a few problems. According to the GitHub page: Self-collision during homing fixed. Connection of the ball joint block with screws only was not well constrained and could be rotated a bit. No reliable way to ensure consistent linkage rod length Unnecessary ball joint friction Accurate ball position heavily dependent on print quality and corner rounding Rubber bands could not be changed or removed once glued in. We...
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Thunderbolt Strikes Windows98

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If there’s one thing everyone hated about Windows 98, was the lack of USB4.0 support. We remember vividly the cries of anguish at the launch party when we found out that 21 years in the future, the operating system wouldn’t support the then-undreamt of speeds of the thunderbolt-based fastest USB protocol. After two decades of living with this crushing disappointment, [Yeo Kheng Meng] has delivered the goods: the most modern of USB interfaces on some very much not modern versions of windows . This builds on [Yeo Kheng Meng]’s work on xHCI drivers for USB2.0 support, which we covered at the time . Like that hack, this one applies to Windows 98 through 7, and has a similar level of LLM-wrangling involved. There are actually a few parts to it– one is a USB3.0 driver, which replaces the old xHCI98 driver and is available on GitHub. On Windows98, USB3.0 speed caps out around 200 MB/s, likely restricted by Windows98’s maximum request limit of 64kB on USB transf...
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