DIY Ribbon Element Upgrades A Studio Microphone

For those with some experience with pro audio, the term “ribbon microphone” tends to conjure up an image of one of those big, chunky mics from the Golden Age of radio, the kind adorned with the station’s callsign and crooned into by the latest heartthrob dreamboat singer. This DIY ribbon mic is none of those things, but it’s still really cool.

Of course the ribbon mic isn’t always huge, and the technology behind it is far from obsolete. [Frank Olsen]’s ribbon mic starts out with gutting a run-of-the-mill studio mic of its element, leaving only the body and connector behind. The element that he constructs, mostly from small scraps of aluminum and blocks of acrylic, looks very much like the ribbon element in commercial mics: a pair of magnets with a thin, corrugated strip of foil suspended between them. The foil was corrugated by passing it through a jig that [Frank] built, which is a neat tool, but he says that a paper crimper used for crafting would work too. There’s some pretty fussy work behind the cartridge build, but everything went together and fit nicely in the old mic body. The video below was narrated using the mic, so we know it works.

Fun fact: the ribbon microphone was invented by Walter Schottky. That Walter Schottky. Need more on how these mics work? Our colleague [Al Williams] has you covered with this article on the basics.

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Dynamic bicycle headlight uses the open road as a display

This thing is so cool it almost looks fake. But [Matt Richardson] isn’t a hoaxster. He actually built what might be called a heads-down display for your bicycle. He refers to it as a headlight because it borrows a similar function. It mounts on the handlebars and shoots light off the front of the bike. But it’s more than just a battery and a bulb, this uses a pico-projector to give that light some meaning. In the video after the break he shows it off on the streets of NYC.

So far he’s only displaying information that has to do with the speed of travel, but the proof is there just waiting for a brilliant new use. Feeding the projector is a Raspberry Pi board. For this prototype [Matt] mounted it, along with the portable cellphone charger which plays the role of the power source, on a hunk of hardboard strapped inside the bike frame.

If you’re thinking of doing this one yourself beware of the BOM price tag. That projector he’s using runs upwards of $400. We wonder if you could hack together a rudimentary replacement with an old cellphone screen and this diy film projector?

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Surviving a hacker conference

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With another hacker conference looming in front of us, it’s time to start thinking about hardware security. Hacker conventions have the most hostile network you’ll ever encounter. [Security4all] points out that 25C3 already has an extensive page on securing your hardware. It starts from the ground up with physical security, BIOS passwords, and locking down bootloaders. There’s a section on securing your actual OS and session. Finally, they cover network usage. It mentions using SSH for dynamic forwarding, which we feel is a skill everyone should have. We’ve used it not just for security, but for bypassing brainless bandwidth restrictions too. There’s also the more trick transparent version. Every piece of data you bring with you, you risk losing, so they actually recommend just wiping your iPhone and other devices before attending. It’s important to remember that it’s not just your own data at risk, but everyone/thing you communicate with as well.