| 摘要 |
PURPOSE:To accurately tune with a receiving broadcasting station at the time of automatically feeding steps by interlocking with a step frequency switching switch connected to the control terminal of a PLL controller and providing a switch for switching the pulse width of the meter output of an IF amplifier. CONSTITUTION:When the step frequency is small, the step frequency selecting terminals(e) and (f) of the PLL controller 14 are connected through the contacts (h) and (i) of step switching switch 16 and when the step frequency is large, the step frequency selecting terminals (e) and (g) of the PLL controller 14 are connected through the contacts (h) and (j) of the step switching switch 16 so as to output a stop signal in a wide pulse width. Thus, the pulse width of the stop signal is made narrow when the step frequency is small and the pulse width of the stop signal is made wide when the step frequency is large, so that the received frequency can be accurately stopped at the time of automatically feeding steps.
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