We found this circuit in the July 1988 Radio Electronics magazine. The frequencies are given by capacitor C1 and the voltage input is made at pin 1.
This full wave source uses germanium diodes, and its current is a few milliamps. We found it in an...
This circuit is from a 1968 documentation. It makes use of thermistors (NTC) to indicate...
This small transmitter has an RF amplifier stage with coupling made from the central socket of the...