Found in a 90s 303 Circuits, this circuit triggers a load from a 50 mV audio signal. When the signal ceases, the charge remains active for 2 seconds.
This is the traditional unijunction transistor relaxation oscillator circuit for the audio band. The...
This is half of a 4-channel amplifier from a system published in the October 1971 issue of Radio...
This circuit works both as a grid-dip (transistorized) and as an oscillator. The circuit is from a...