
This little o-scope is built entirely using valves (tubes), built by [Ian Wilson] and [Hans Summers]. [Hans]’ site covers everything from monitor gutting to a Z80 viscometer, it’s worth taking some time to poke around. Thanks to [Elliot] for sending in this one on the tips line.
diy444 Articles
DIY Frequency Meter

[Wolf] sent in this site a while back, and I thought that this frequency meter how-to looked pretty useful. It’s based on an Atmel AT89C52 and a gutted multi-meter. The circuit isn’t too bad. (The worst of it has to be all the display lines.) The Atmel grabs the signal to be measured and drives the display, so the parts count is pretty low.
DIY A/V Switch

I knew this was coming out, but [mike] was kind enough to remind me. [Ben Heckendorn]’s latest How-To is up on engadget. He provides a method of building your own A/V switch with as many inputs as you want, cheap. Each input uses a $.50 bus switch – literally, you could build one with 20 inputs if you really wanted to. (add some shielding if you do) If you’ve got too many game consoles, this might be your ticket. You can probably use the same trick to build a component video switch if HD’s your thing.