We found this circuit in a Hands-On Electronics from the 90s. The circuit must be connected to an external amplifier. Frequency control is capacitive, using an antenna for this purpose
This circuit was obtained in a 90’s Popular Electronics. The frequency depends on C1, a component...
This short-range circuit can act as a wireless microphone. We got the schematic and the printed...
This sophisticated function generator circuit appeared in the September 1972 issue of Radio...