| 摘要 |
PURPOSE:To control a receiving frequency band by applying the electric power source for controlling the lower limited voltage, to the tuner part through a diode. CONSTITUTION:The channel selection part 4 is constituted of a band switching part 41 and a channel switching part 42. The sliding terminal 51 of each variable resistor 5 applies the tuning voltage Vt to the tuner 1 through the channel switch 45. The electric power source 7 for controlling the lower limited voltate applies the prescribed lower limited voltage V 1 to the tuner 1 through the diode 8. Accordingly, the tuning voltage never becomes V 1 or below, and the receiving frequency band is controlled exactly. |
