| 摘要 |
PURPOSE:To reduce crosstalk by controlling the amount of load of an inductive load and a capacitive load connected to a load circuit of a modulation circuit applying orthogonal biphase modulation to the 1st and 2nd color difference signals so as to attain the balance adjustment of upper and lower side bands. CONSTITUTION:A signal B-Y being the 1st color difference signal and a carrier signal C are inputted to a modulator 11 and a signal R-Y being the 2nd color difference signal and a signal C' being the phase deviation of the carrier C by 90 deg. are inputted to a modulator 12. A load circuit 10 comprising a capacitor 20, a coil 21 and a variable resistor 22 is connected to the modulators 11, 12, outputs are combined and the result is sent to a CCU 2 from a terminal 23. The quantity of the inductive and capacitive load of the load circuit 10 is controlled by adjusting a slider of the variable resistor 22 to attain the adjustment so that the upper/lower side bands are balanced. Thus, the occurrence of the crosstalk is reduced.
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