| 摘要 |
PURPOSE:To facilitate an assured channel selection by giving a variable division ratio to a frequency divider with higher priority than a preset division ratio during the sweep of frequency and then giving higher priority to the preset division ratio when a channel selection switch is pushed. CONSTITUTION:An analog signal generator 15 is operated 16 to deliver analog signals from a slider 17. These analog signals are supplied with a division ratio N to a main memory 30 and data loading circuits 37-1... after A/D conversion 18 and data conversion 19. The variation of the analog signal is detected 20 and selivered to set FF24-1 and 24-2, and AND circuits 31-35 are turned on by the sweepable signal obtained from a set state of the FF24-1. Then the data on a variable division ratio N obtained from the memory 30 is supplied to a programmable frequency divider 11 and then to an MIX (not shown in the diagram) for sequential channel selections. When a desired channel is received, the movement of the slider 17 is stopped and a preset memory switch 43-1 is set. This ensures an accurate sweep action and also assures the reception of a preset channel. |
