Measurement of Nonlinear Distortions in Color Television Systems

Charles W. Rhodes

NTSC color television tests for differential phase and gain in transmission facilities have shown the need for better measurement techniques. Two problems to be solved are the need to readjust the hue control between TV channels and distortion related to changes in average picture level. Dynamic gain may occur in the chrominance signal, the whole signal, or in the luminance and sync signals only. Dynamic phase affects the chrominance signal only. Present differential phase measurements are made with subcarrier levels smaller than the burst signal or chrominance signals of saturated parts of the picture. By adding a variable-amplitude subcarrier signal of constant phase to the variable luminance lines, we can probe the entire range of luminance signal values to detect the presence of distortions sensitive to chrominance amplitude.

Print ISSN
Published
1970-01
Content type
Original Research
DOI
10.5594/J16709