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).
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...
The purpose of this circuit is to improve a trigger circuit using a zener diode. The circuit was...
This interesting circuit of the American publication Electronics Handbook Volume XIII 1993 shows a...