A Sneak Peek At Anechoic Chamber Testing

[Mathieu Stephan] has something new in the works, and while he isn’t ready to take the wraps off of it yet, he was kind enough to document his experience putting the mysterious new gadget through its paces inside an anechoic chamber. Considering the majority of us will never get inside of one of these rooms, much less have the opportunity to test our own hardware in one, he figured it was the least he could do.

If you’re not familiar with an anechoic chamber, don’t feel bad. It’s not exactly the sort of thing you’ll have at the local makerspace. Put simply it’s a room designed to not only to remove echos on the inside, but also be completely isolated from the outside. But we aren’t just talking about sound deadening, the principle can also be adapted to work for electromagnetic waves. So not only is in the inside of the anechoic chamber audibly silent, it can also be radio silent.

This is important if you want to test the performance of things like antennas, as it allows you to remove outside interference. As [Mathieu] explains, both the receiver and transmitter can be placed in the chamber and connected to a vector network analyzer (VNA). The device is able to quantify how much energy is being transferred between the two devices, but the results will only be accurate if that’s the only thing the VNA sees on its input port.

[Mathieu] can’t reveal images of the hardware or the results of the analysis because that would give too much away at this point, but he does provide the cleverly edited video after the break as well as some generic information on antenna analysis and the type of results one receives from this sort of testing. Our very own [Jenny List] has a bit more information on the subject if you’d like to continue to live vicariously through the accounts of others. For the rest of us, we’ll just have to settle for some chicken wire and a wooden crate.

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Building A Hardware Store Faraday Cage

Most Hackaday readers are no doubt familiar with the Faraday cage, at least in name, and nearly everyone owns one: if you’ve ever stood watching a bag of popcorn slowly revolve inside of a microwave, you’be seen Michael Faraday’s 1836 invention in action. Yet despite being such a well known device, the average hacker still doesn’t have one in their arsenal. But why?

It could be that there’s a certain mystique about Faraday cages, an assumption that their construction requires techniques or materials outside the realm of the home hacker. While it’s true that building a perfect Faraday cage for a given frequency involves math and careful attention to detail, putting together a simple model for general purpose use and experimentation turns out to be quick and easy.

As an exercise in minimalist hacking I recently built a basic Faraday cage out of materials sourced from Home Depot, and thought it would be interesting to not only describe its construction but give some ideas as to how one can put it to practical use in the home lab. While it’s hardly a perfect specimen, it clearly works, and it didn’t take anything that can’t be sourced locally pretty much anywhere in the world.

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Hackaday Links: November 27, 2016

[Prusa]’s business is doing great. This year, he released the Prusa i3 Mk. 2, a four color upgrade to the printer, and sales are through the roof. There’s just one problem: Paypal just locked his funds. Prusa is turning away from Paypal and given Paypal’s history, this will eventually be worked out. Be warned, though: don’t use Paypal for your hardware business. We’ve seen this same story played out too many times before.

Those millennials are always on their phones. How do you get rid of that distraction? Airplane mode? No, that’s stupid. Put those phones in a metal box. It’s the exact same thing as airplane mode – which is free – but this extra special metal box costs $45 and ships in March. Is this metal box different from any other metal box, like a cookie tin, perhaps? Probably not.

Nothing to see here, folks.

The holidays are here, and it’s time for Cards Against Humanity to do something stupid with other people’s money. This year, they’re throwing money into a hole. No, really. People are contributing money to dig a gigantic hole. There’s a livestream of the digging. Five dollars lets the dig continue for another few seconds. Join in on the holiday spirit: throw your money into a hole.

You don’t want to throw your money into a hole? Buy some stuff on Tindie! There’s robots, CNC controllers, servo drivers, MIDI arpeggiators, USB testers, power supplies, blinky glowy things, and retro gaming stuff. Go plug your Raspberry Pi into some of these gizmos.

The Mechaduino is a board that clips onto a ubiquitous NEMA stepper motor to turn it into a servo motor.  It won 5th place in the Hackaday Prize last month, and we can’t wait to see it integrated into a closed-loop 3D printer. [Chris] came up with an Ethernet-enabled servo-stepper conversion, and now it’s a project on Kickstarter. Of course, you can buy a Mechaduino right now, making the future of stepper motor-controlled desktop CNC very interesting.

Individually addressable RGB LEDs exist, and we’re waiting for Clark Griswold to electrify his house in red, green, and blue. Until then, [Michel built a holiday ornament loaded up with 16 WS2812b LEDs. The star features caps and diodes to make everything work as it should and requires only three wires per star.

Hackaday Links: March 22, 2015

[Liam Kennedy] built a wearable space station notifier it’s on Kickstarter, and now the campaign is in its final hours. It’s very cool; doubly so if you don’t have to talk to a crazy lady who doubts the existence of NASA.

[countkillalot] lost a Raspberry Pi. It was in his apartment, and responded to ping, but he couldn’t find it. Turning the Pi into an FM transmitter revealed its location. Relevant bash.org.

If you don’t listen to the Amp Hour podcast, oh man are you in for a treat. This time it’s [Chuck Peddle], father of the 6502, designer of the KIM-1, and someone with at least three hours’ worth of interesting stories.

MakeIt Labs, the Nashua, New Hampshire hackerspace, has done everything right – they have their 501(c)(3), and they’ve been talking to the city about getting a new space. They have the option of moving into a space three times the size as their current one, and it’s cheaper than the current space. They have an indiegogo to raise the renovation funds for the new space. Oh, hackaday.io supports pages for hackerspaces. Just pointing that out.

Speaking of hackerspaces, yours needs this sign.

A 3-DAY DESERT CAMPING AND TECH-FEST WITH BEER. That’s all you need to know about Arduino Day, an event being held next weekend in the Mojave.

Want to hide from the NSA, or whatever governments or corporate interests are listening in on your phone? Stick it in a microwave. [WhiskeyTangoHotel] tested out a Tek RSA306 spectrum analyzer in a microwave, once with the door open, once with the door closed. If you’re exceptionally clever or have access to Wikipedia, you can figure out what frequencies will leak out of a microwave given the size of the holes in the metal mesh.

Here’s a Flintstones toilet paper holder. It would have been a phonograph, but no one could find a cooperative turtle and bird.

It has been brought to our attention that everyone should be aware ucapps.de still exists. If you want something that does everything with MIDI and SID chips, there you go.

High Voltage Cable Inspection

high-voltage-woker

Have you ever wondered how they inspect high voltage cables without taking them out of service? Check out this video which offers a glimpse into the life of a professional high voltage cable inspector. There are parts of the job you’d expect—namely perching on the cable like a bird, trying to not fall off—but the part of the job you wouldn’t expect is the suit. This suit is made of 75% Nomex, to prevent it from catching fire, and 25% stainless steel thread, turning the suit into a wearable Faraday cage. Of course, because he’s got a Faraday cage mere millimeters from his skin, the cable inspector spends his workday surrounded by half a million volts.  To avoid electric shock, he equalizes the voltage potential between himself and the line before touching the cable.

Depending on your specific phobias, this video might make your job seem really dull… or really really safe.

[via Gizmodo]