This dual-tuned 60 Hz oscillator was found in the Radio Experimenter Special projects of 1993. The circuit has the timing ranges given by C1 which can be changed.
This circuit is from an American publication of the 80's. It makes use of components of the time....
The integrated circuit used in this Electronics Now amplifier is not very common today. However,...
This PA or Public Address amplifier with a few watts of power was found in the March 1986 Radio...