This two-tube circuit, one being a double, was found in Radio Electronics magazine from July 1958. The distance to the microphone depends on noise and losses. The cable must be shielded.
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...