LIMITATIONS OF THE NTSC SYSTEM
system is sensitive to transmission path differences which introduce phase
errors that results in colour changes in the picture.
transmitter, phase changes in the chroma signal take place when changeover
between programmes of local and television network systems takes place and when
video tape recorders are switched on.
chroma phase angle is also effected by the level of the signal while passing
through various circuits. In addition crosstalk between demodulator outputs at
the receiver causes colour distortion.
requires the use of an automatic tint control (ATC) circuit with provision of a
manually operated tint control.