We found this circuit in the Radio Electronics magazine of December 1972. It generates signals in 6 frequency bands, being indicated for experimental applications with TTL circuits.
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...