B&K Precision 1249B - Manual - Manual (Page 17)

17
THE NTSC COLOR VIDEO SIGNAL (CONT.)
(saturation) set forth by the NTSC. This is the test signal
used in broadcasting studios and transmitting equipment.
This makes the NTSC Generator a superior instrument
for servicing and adjusting color television receivers and
all types of other video equipment. An NTSC color bars
pattern is specified or recommended for most tests and
adjustments in video cassette recorders.
The precision of the NTSC color bars signal is beyond
comparison with that of a low cost color bar generator. A
color bar generator usually produces all hues at the same
luminance level (or with no luminance component) and
same chroma amplitude, which of course is not equivalent
to the color signals being transmitted by broadcast stations.
Many hues are oversaturated. Also, the chroma phase angle
is normally produced by using a carrier that is offset enough
from 3.58MHz so that 360° phase shift occurs during each
horizontal line. This produces a gated rainbow pattern
rather than specific, phase controlled colors.