We found this circuit in an English publication from the 1980s. The circuit uses current components and can be tuned for frequencies between 300 and 1500 Hz.
The configuration presented below was obtained in the Linear Application Handbook of the National...
This circuit was found in December 1983 Radio Electronics magazine. The maximum output current is 1 A...
This untuned circuit uses one of the world's first commercial transistors, the CK722, having been...