Radio receiver with underpass detector

摘要

A radio receiver avoids overshoot or undershoot of its audio output caused by inadequate AGC loop response when driving under an underpass and then back into an unobstructed environment. The AGC loop response time is changed upon detection (35) of the sudden decrease in signal level when entering the underpass. The state of the AGC loop prior to entry into the underpass is stored (36). Upon exiting the underpass, the stored values are restored (39) so that a proper reception level is immediately obtained. <IMAGE>