| 摘要 |
PURPOSE:To obtain easy-to-see channel selection display while facilitating channel selection, by providing two regulated power sources to a power source part for tuning and by alternating the both according to band change-over operation. CONSTITUTION:Band change-over part 6 is provided with three one-circuit three- contact change-over switches so that they interlock, and a band selected through the switching of change-over switch S1 can be received. Respective change-over contacts of change-over switches S2 are connected to voltage source 7. Voltage source 7 has two high and low constant voltage sources; the high voltage source is connected to UHF and VHF high-band side contacts U and VH of switch S2, and the low voltage source to the VHF low-band side contact. In UHF and VHF high-band reception, a high voltage is applied from voltage source 7 to tuning variable resistor 5 and in VHF low-band reception, a low voltage is applied. For this purpose, the upper limit and lower limit of the tuning voltage are regulated by adjusting semifixed resistors 8, 8a and 8b to expand the tuning range on the channel-selection scale to the circumference of the center part, so that while the tuning operation is facilitated, easy-to-see channel selection display can be obtained. |
