| 摘要 |
PURPOSE:To use a device as an interference signal eliminating receiver and an AM stereo receiver, by providing upper and lower interference signal eliminating switching terminal and an AM stereo switching terminal in a matrix circuit. CONSTITUTION:Carrier signal components obtained by an amplitude limiter 3 are not only applied to a synchronizing detector 1 but also supplied to a phase comparator 4 of a PLL circuit. Consequently, the synchronizing signal supplied from the PLL circuit to asynchronizing detector 2 is different from said carrier signal components in phase by 90 deg.. A demodulation signal obtained from synchronizing circuit 1 and 2 and the PLL circuit is supplied to a matric circuit 8. The circuit 8 is provided with 180 deg. phase shifters 9 and 11, and the interference signal of a lower side-band monaural is eliminated by switching an interlocking switch SW to the L side, and the interference signal of an upper side-band monaural is eliminated by switching it to the U side, and a stereo signal is obtained from terminals R and L by switching it to the ST side. |
