| 摘要 |
PURPOSE:To decrease the time required for tuning by providing a rotary angle detecting means detecting a rotary angle of a tuning shaft and activating a driver forcibly until the rotary angle or the tuning shaft reaches a rotary angle with respect in the vicinity of a prescribed frequency so as to prevent the mis- tuning due to noise or side band or the like. CONSTITUTION:A rotary angle detecting means 12 detects a rotary angle of a tuning shaft indirectly to detect the rotary angle of a motor 8 and consists of a pulse encoder 13 and a counter 14. A control circuit 11 drives a motor forcibly till the rotary angle Q1 or Q2 of the tuning shaft in the vicinity of an object frequency. Since the tuning shaft is driven forcibly without detecting the demodulated output of a radio receiver up to the vicinity of the prescribed frequency, the mis-tuning is prevented and the rotating speed of the tuning shaft is quickened to reduce the time required for tuning.
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