This traditional signal injector configuration was obtained in a 1977 amateur radio manual. The frequency is given by the capacitors and the supply can be made with 1.5 or 3 V.
Found in a 1964 Electronic Design, this circuit for 300 mA loads uses components from that period. It...
This circuit was originally suggested in a 1968 publication to generate a white mark (frame) on a...
Found on Popular Electronics this circuit has variations found throughout this site and section....