| 摘要 |
PURPOSE:To simplify the constitution of a reception detecting means, by counting the broadcast frequency to obtain reception detected outputs and the number of tuning frequencies adjacent thereto, and performing channel selection based on this count value. CONSTITUTION:The channel number C to be received from the memory is read out to control a phase locked loop 16 and the reception state of corresponding tuning frequency is made. Next, the channel number C is increased one by one until the reception detected output is obtained from envelope detection circuits 18, 19. When the reception-detected output is obtained, the number of tuning frequencies in which the reception-detected outputs before and after the said output are obtained, is counted, and the tuning frequency is swept backward based on the count value to be returned to the broadcasting frequency. |
