| 摘要 |
Stereo decoder for multiplex signals comprising a demultiplexer for decoding the left-hand and the right-hand sound signal of a stereo multiplex signal, a phase-locked loop which includes a phase-locked oscillator and a multiplicative phase detector, and a pilot elimination circuit, for reducing the pilot signal of a multiplex signal, which is used in two manners, namely, to suppress the pilot signal in the decoded left-hand and right-hand sound signal at the sound output of the demultiplexer, and to suppress disturbances in the frequency control of the phase-locked oscillator caused by sound components of the multiplex signal. To this end the phase detector comprises a differential reference input stage to which on the one hand the complete stereo multiplex signal is applied and on the other hand, in phase (common mode) therewith, the output signal of the pilot elimination circuit, that is to say the stereo multiplex signal with the suppressed pilot signal. |
