| 摘要 |
PURPOSE:To prevent malfunctions dependent upon time delay of the output of a narrow-band filter, by detecting the subcarrier of a sub-signal and by giving a time constant to the output and by applying it to a switching circuit. CONSTITUTION:In the double broadcast receiving state, the subsignal carrier of 2fH generated at output terminal 19 of band-pass filter 6 for subsignal is amplified and detected by squelch signal generating circuit 17, and a squelch signal where fall of the detection output is rapid and rise is slow is output from output terminal 20. Then, since deciding circuit 12 inhibits switching for a decision level or less, malfunctions can be prevented even if the detection output of reed filters 10 and 11 is delayed. |
