| 摘要 |
A chrominance take-off circuit effecting a transmission zero at a predetermined frequency approximately equal to one-half the chrominance subcarrier frequency. The circuit includes a capacitive branch coupled in series with a parallel RLC branch that is resonant at approximately the subcarrier frequency. At frequencies below the subcarrier frequency the RLC branch is equivalent to a series-connected resistance and inductance. At the predetermined frequency the magnitude of the impedance of the capacitive branch is substantially equal to the magnitude of the impedance of the equivalent inductance, resulting in maximum attenuation of luminance signals at the predetermined frequency.
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