Learning Event 3:
DESCRIBE THE NTSC COLOR TRANSMISSION SYSTEM
1. Compatibility is one of the primary requirements of the color television
system.
Compatibility provides a high definition black and white picture for
present standard black and white receivers without any modifications to the TV
receiver. This means that the following must apply:
a. First, a color telecast must provide a full 6-MHz black and white signal with
the same amplitude modulation, sync, and blanking characteristics as does any
ordinary standard monochrome telecast.
b. Second, the chrominance information, which includes the hue and saturation
variable of color, must be transmitted within the standard 6-MHz television
channel.
c. Third, the transmitted chrominance information must not in any way cause
objectionable interference with the black and white signal (the brightness variable
of color).
d. At first glance it seems to be a difficult task since the 6-MHz channel is
apparently already well filled. However, you will learn that it is not impossible
to transmit the chrominance information along with the monochrome signal within the
standard 6-MHz television channel.
2. As previously stated, color television programs must be transmitted so they can
be faithfully reproduced by black and white receivers.
This feature is known as
compatibility (fig 1-10).
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