This is the power step of the previous circuit. Output transistors must be mounted on good heat sinks. The circuit is from documentation from the 60s.
This circuit is from Radio Electronics from February 1987. The frequency is given by the crystal that...
In this circuit, a light-sensitive SCR or Light Activated SCR determines the operation of an...
This 3-transistor circuit was found in a Mullard manual from 1960. The transistors are germanium of the...