Using a 709 integrated circuit this circuit was found in the June 1972 issue of Radio Electronics magazine. More modern operational equivalents can be used. The power supply is symmetrical.
This small blocking oscillator for approximately 1000 Hz was found in an American documentation from the...
An audio signal is applied to the input of this circuit. Depending on the position of the selector...
Using only one LM107 operational amplifier, National Semiconductor suggests the circuit in the...