This is the typical circuit of a local oscillator for a superheterodyne FM receiver. The circuit was found in a 1980s documentation and is typical of early and early receivers.
This two-transistor amplifier can be used as power stage for intercom, experimental receivers,...
This circuit from an old 1978 publication uses germanium transistors but can be implemented with...
This circuit appeared in Radio Elecronics magazine in 1968. The operating circuit is a...