This circuit was found in an Electronics Now from the 90's. The integrated regulator circuit and the power transistor must be equipped with heat radiators.
This two-transistor circuit was found in the 1990 special issue of Radio Electronics Experimenter...
This low power TTL circuit (Low Power Schottky) can generate rectangular signals on a 10 MHz...
This non-inverting AC amplifier was found in the February 1990 issue of Radio Electronics...