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 amplifier was published in the July 1961 Radio Electronics magazine. It announced the release of...
This circuit was found in a 1967 Electronics World. SCRs are according the controller load,...
This sophisticated circuit using a liquid crystal display was found in Radio Electronics from the...