| 摘要 |
PURPOSE:To eliminate noise and to attain reproduction with high fidelity by applying a signal where the phase and output of a discriminating signal are adjusted to a main signal outputted from a BPF or an L+R signal. CONSTITUTION:The discriminating signal in 922.5Hz at the duplex sound braod- cast and in 982.5Hz at stereo broadcast is applied from an AM detector 15 to a phase and output control circuit 18 connected to the AM detector 15, the phase and output level are adjusted and a prescribed signal is formed. The signal is applied to the main signal and the L+R signal and inputted to an emplifier 3. Thus, the discriminating signal mixed at the main signal is cancelled with a signal formed at the circuit 18. Thus, the discriminating signal is prevented from being mixed to the main signal and the stereo L and R signal of the duplex sound signal being an output of low frequency amplifiers 7 and 13. |
