This primitive solar radio was found in a Gernsback publication from 1960. The transistor is made of germanium of the time and the earphone is magnetic with high impedance.
This circuit draws one of the three possible guesses of a sports lottery logo: column 1, 2 or the...
This Tesla coil was found in the November 1994 issue of Electronics Now magazine. T1 is a TV...
Hartley oscillator operates in the audio range. Frequency can be adjusted by P1 and also depends...