Pete Friedrichs, author of the can’t-be-recommended-highly-enough Voice of the Crystal and Instruments of Amplification (which I review in MAKE Volume 21), has posted online his two-part article “Fun With Homebrew Cuprous Oxide Diodes,” which originally appeared in the Xtal Set Society Newsletter. In it, he shows you how to build an old-school Cuprous Oxide-based radio detector (diode) using little more than some metal scraps, misc hardware, and garden shed/kitchen chemicals. The results don’t sound all that compelling, but given the crudity of the components… And the detector stand you build in the process can be used for experiments with other natural semiconducting materials. And Peter always does such a lovely job on these builds. It’s like a piece a tech art, cobbled together from junkbox bits.
From MAKE magazine:
MAKE Volume 21 is the Desktop Manufacturing issue, with how-to articles on making three-dimensional parts using inexpensive computer-controlled manufacturing equipment. Both additive (RepRap, CandyFab) and subtractive (Lumenlab Micro CNC) systems are covered. Also in this issue: instructions for making a cigar box guitar, building your own CNC for under $800, running a mini electric bike with a cordless drill, making a magic photo cube, and tons more. If you’re a subscriber, you may have your issue in hand already, and can access the Digital Edition. Otherwise, you can pick up MAKE 21 in the Maker Shed or look for it on newsstands near you!