FM stereophonic signal demodulator - has frequency discriminator for FM stereo modulated carrier

摘要

The stereo signal consists of a main channel signal, of a 19 KHz pilot signal and of an auxiliary channel signal, a.m. on the pilot signal second harmonic in order to obtain two stereo signals with different polarities at the frequency discriminator outputs. It comprises a first and a second stereophonic demodulator to which one and the other of the stereo signals are applied. Each of them generates two channel output signals, with a cross talk component. An attenuator for one of the stereo signals, whose attenuation corresponds to the crosstalk component magnitude, and a device for the two demodulator output signals combination, deliver two output signals with suppressed cross talk components. Each frequency discriminator has a ratio detector.