Crystal Radio
'Twas a kit.This crystal radio was the second project I built for my electronics class, freshman year of college. It was a kit from Vectronics and I built it in about 2 hours. As crystal radios do, it receives AM signals, and on campus, I can pick up 2 whole stations!
The clip on the left with the red wire attached is the antenna clip. The clip below that with the black wire is the ground clip. The horribly uncomfortable piezo earphone thing is connected across the two clips opposite them. The diode between the two middle clips is where the circuit gets its name, as when these radios were first developed, a crystal was used there instead.