| 摘要 |
PURPOSE:To decrease the number of component parts, by using an inverter circuit that improves the disturbing characteristics to the ferroelectric field cross modulation in common to the FET for both the UHF and VHF. CONSTITUTION:The power supply voltage is applied to the drain 2a of the FET21 via the power supply terminal 14a when receiving the VHF, and thus a high frequency amplifying circuit of the VHF tuner works. In this instant, the AGC voltage is applied to the base of the transistor 15 to flow the collector current. Then the voltage obtained by subtracting the voltage drop component caused by the resistance 35 from the voltage applied to the power supply voltage terminal 40 is produced at the collector of the transistor 15. And the voltage obtained by giving a voltage division to the voltage produced at the collector of the transistor 15 by the resistances 27 and 28 is applied to the 1st gate 4a of the FET21. When receiving the UHF, the power supply voltage is supplied to the drain 2b of the FET22 via the power supply voltage terminal 14b. In this case, the voltage for reception of UHF is applied to the emitter of the transistor 15 from the terminal 14b and via the resistance 38 and the diode 39. |
