Hang your heads in shame, my friends. This dude is getting ready to homebrew his own transistors. None of that store-bought stuff for him. He is a few steps away from breaking free of the GLOBAL TRANSISTOR CARTEL that has been abusing us so-called "homebrewers" for so many years. This guy really puts the home in homebrew.
Plus he has a seriously cool shop enabling him to do some excellent metal and chemical work.
Thanks to Hackaday for alerting us to this.
The best I've done is make my own diode for a crystal radio. Years ago I had a friend ask me if I'd ever heard of using a razor blade in a crystal radio. He remembered hearing something about it from his grandfather. I said I hadn't. Some time later when I had read about foxhole radio's, and I brought it up to him, he now knew about it too.
ReplyDeleteI've not read too much about it. But I'm sure I've seen the phrase "Blue blades" used in relation to what sort of blade was used. More recently I read you can heat the blade up to tarnish it. This is from Wikipedia "One common type was made from an oxidized razor blade (rusty or flamed)".
I used to work in the meat industry, and the skinning knifes we used were made of a steel that would rust. 'Dexter Russell' an American made knife was very popular. They were easy to sharpen on the stone, and kept a good edge just using a sharpening steel. It was common practice to rub a bit of fat on the knife at the end of shift to limit rusting. The blade would always look tarnished. These knifes would eventually be not allowed, and stainless steel knifes had to be used. The same went for wooden handled knifes. They had to be plastic, as this was more hygienic.
I'm wondering if these early razor blades were made of a similar steel, that would rust. That would oxidise. Anyway I once put together a very quick crystal radio. Coil on a ferrite rod. Big metal variable capacitor. Germanium diode. Now this wasn't a true crystal radio because I used an amplifier to the speaker. I wanted to experiment with my own foxhole type diode. So with a local AM station coming in loud and clear I removed the germanium diode. I used one of my oxidised skinning knifes in place of the razor blade. This went to one connection and a safety pin to the other. It didn't take too long of moving the pin around on the blade of the knife and I had audio. I had to find one of the sweet spots. Some places I'd hear nothing. I'd move it to a tarnished oxidised looking spot on the blade and boom. I had my crude version of a foxhole radio.
Oh man Trevor, that's great. Take a look at this site. Scroll down to the "razor blade detector kit." http://www.xtalman.com/detectors.html
ReplyDeleteI have made crystal radios with chunks of galena and a phosphor bronze cats whisker. Also with Fools Gold from Juneau, Alaska. Great fun. 73 Bill
Sam Zeloof has some YouTube videos in a similar vein.
ReplyDeletehttp://sam.zeloof.xyz/
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