Found in a 1964 Electronic Design, this circuit shows how to modulate a signal with a dynamic low impedance microphone. The circuit operates in the FM range (88 to 108 MHz).
This configuration similar to many of this site was found in 1965 General Electric documentation. Modern...
This circuit is from an American manual from 1974. It uses a diac (Q1) and the SCR can be the...
This circuit works both as a grid-dip (transistorized) and as an oscillator. The circuit is from a...