| 摘要 |
PURPOSE:To eliminate a difference in sensitivity between both UHF and VHF reception times by controlling a television receiver with an up-converter to make the UHF-reception gain of an intermediate-frequency amplifier different from the VHF- reception gain. CONSTITUTION:An operating voltage is supplied from terminal 31 to UHF tuner 10 and intermediate-frequency circuit 15, to up-converter 20 via VHF-side contact V of switch circuit 32, and to switching circuit 2 via VHF-side contact V and UHF-side contact (u) of switch circuit 32, thereby switching circuit 2. A voltage obtained at VHF-side contact (v) of circuit 32 is partially supplied to intermediate- frequency circuit 15 to decrease the gain of circuit 15 by a fixed value. Consequently, the sensitivity of UHF reception can be made equal to that of VHF reception. |
