CAR RADIO RECEIVER WITH AM BROADCAST AUTOMATIC CHANNEL SELECTION SENSITIVITY SETTING FUNCTION

摘要

PROBLEM TO BE SOLVED: To provide a car radio receiver with an AM broadcast automatic channel selection sensitivity setting function for automatically switching channel selection sensitivity in accordance with a state of a radio wave. SOLUTION: The radio receiver is provided with: a signal strength judgment means for judging the signal strength of an AM broadcast station on the basis of an output control voltage V of an RF AGC 3; a low sensitivity seek mode setting means for automatically setting a low sensitivity seek mode LO to the receiver when the output control voltage V exceeds a prescribed reference value V1 in the case of seeking; an ordinary sensitivity seek setting means for automatically setting an ordinary sensitivity seek mode DX to the receiver when the output control voltage V is the prescribed reference value V1 or below in the case of seeking; a high sensitivity seek mode setting means for automatically setting a high sensitivity seek mode SDX to the receiver when the number of broadcast stations N selected by one cyclic seek within reception bands is a prescribed number of stations N1 or below; and a channel selection quality hold means for carrying out seeking so as not to stop the channel selection in the case of seeking when a noise level included in an output sound signal S extracted by a filter 5 exceeds a prescribed level. COPYRIGHT: (C)2006,JPO&NCIPI