ELECTRONIC TUNING RADIO RECEIVER

摘要

PURPOSE:To attain an automatic switch between AM and FM bands by providing channel selection switches for AM and FM station independently of each other. CONSTITUTION:Either one of switches AM1-AM5 and FM1-FM5 is turned on for channel selection. Then the prescribed numerical value is read out of a memory 5 and applied to a PLL2. In this case, a flip-flop 4 is set to designate a band with the rise of the output of an OR gate G1 or G2. Then a turner 1 is ready for reception of AM or FM. A sweep is carried out when the frequency of a station is not clear. In such a case, a switch AMSCAN or FMSCAN is operated. Thus a frequency sweep is automatically carried out at the AM or FM band.