The integrated circuit used in this configuration for noise reduction on FM radios is not common today. The circuit is from 80s documentation and the reduction rate obtained is in the 10dB order.
This circuit with the 741 operational amplifier was found in the March 1995 issue of Electronics Now...
This circuit was found in a General Electric documentation from 1966. It uses discrete components...
We found this circuit in a French technical documentation from 1982. The circuit can be...