| 摘要 |
PURPOSE:To simplify the circuit constitution by sweeping the reception band comprising 1st and 2nd bands having respectively a prescribed frequency range so as to revise the frequency division of a frequency divider. CONSTITUTION:In operating an automatic sweep key, whether or not the frequency corresponding to the frequency division ratio set at present in a programmable frequency divider 5 is the frequency of the FM band of the eastern Europe is discriminated. When the frequency is the frequency of the FM band of eastern Europe, the up-sweep mode is attained. On the other hand, when the frequency division ratio N of the programmable frequency divider 5 is coincident with the frequency division ratio N1 before a detection signal So is outputted, the frequency division ratio N2 corresponding to the lower limit frequency of the FM band of western Europe is set to the programmable frequency divider 5 to continue the up-sweep. When the presence of the detection signal So from a signal detection circuit 17 his decided and a detection signal is outputted during the sweeping, the sweeping is stopped.
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