This circuit was found in documentation for radio amateurs of the 1980s. This is the so-called roger-beep, which is the beep that is transmitted when the talk-listen function is changed.
This circuit was obtained from the March 1994 Electronics Now magazine. The circuit uses a common...
This good gain circuit was found in a Popular Electronics from April 1967. The transistors are...
Found in an Electronic World, this circuit is designed to control solenoids up to 5 A. The circuit...