This 300 Hz to 3.4 kHz filter was found in the May 1989 Radio Electronics magazine. The circuit requires a symmetrical power supply.
Found in the March 1992 Radio Electronics magazine, this circuit has two supply voltages. The...
This transmitter, indicated for espionage applications, is permanently powered by the power grid....
This oscillator or clock generator generates rectangular signals and frequencies up to 100 kHz....