A CIRCUIT FOR MINIMIZING THE EFFECTS OF THE LEVEL OF RECEIVED BROADCAST SIGNALS ON SEPARATION IN A STEREO-PHONIC RECEIVER

摘要

In a receiver for processing of broadcast signals modulated in amplitude by a summation signal of two stereophonic related signals and in angle by a difference signal of said two related signals, apparatus is provided for maintaining the demodulated summation and difference signals in a predetermined relationship. A variable gain amplifier 31 processes the difference signal at 28 under control of the receiver AGC voltage from 29. The output of the variable gain amplifier is supplied to a matrix means 32 for combining with the summation signal from 34 to derive a pair of stereophonic related signals substantially insensitive to the level of broadcast signal being received. Further apparatus 35 is provided for placing the receiver in a monophonic mode of reception when the level of a broadcast signal being received is below a predetermined minimum. IMAGE