| 摘要 |
PURPOSE:To make invariably excellent reception possible by selecting an excellent broadcast wave by evaluating broadcast waves in terms of both signal levels and noise levels. CONSTITUTION:The output of noise level detecting circuit 9 is compared to a reference level by comparing circuit 16. When a noise level is high, timer 21 is put into operation to decide the noise level again a certain time later and when it is high again, tuning circuit 10 receives the next broadcast. The output of signal level detecting circuit 8, on the other hand, is inputted to comparing circuits 17 and 18. Comparing circuit 17 decides whether a sufficiently large signal level arrives by making a comparison to a setpoint. Comparing circuit 18 makes a comparison with a setpoint low enough for difficult listening. Then, a broadcast which has the highest signal level or whose signal level and noise level are not too low is selected. Under inferior reception conditions, muting operation is done. |
