| 摘要 |
PURPOSE:To allow a listener to always listen to pleasant reproducing sound by comparing output levels of a narrow band filter and a broad band filter and adjusting the level ratio of signals from the narrow band filter and broad band filter in response to an output signal of a comparison means transmitting a level signal according to the difference of the output level. CONSTITUTION:When an interference disturbance takes place or a level of a reception signal is weak, an output level of a broad band filter 15 is larger than an output level of the narrow band filter 16. Thus, a signal of a level in response to the difference of the output levels of the broad band filter 15 and the narrow band filter 16 is outputted from a differential amplifier circuit 27, a level adjusting means 21 applies a detection signal to an output terminal 24 while the detected output signal from the detection circuit 20, that is, the level ratio of the output signal from the narrow band filter 16 is increased in response to the level of the output signal of the differential amplifier circuit 27. Thus, a reproducing sound with a high SN ratio is outputted from a speaker connected to an output terminal 24. |
