ABSTRACT
This chapter focuses on National Television System Committee (NTSC). NTSC and most analog TV transmission systems invert the video signal for transmission so that a "negative" of the desired picture is transmitted. The purpose of this inversion is to disguise noise acquired in the transmission path. Television audio is sent on a separate carrier located 5.75 MHz above the lower channel edge, and thus 4.5 MHz above the visual carrier and only 250 kHz below the upper channel edge. For NTSC US channel 3, the audio carrier is located at 65.75 MHz. Color in analog systems is transmitted as differential color information, where the green-minus-luminance (G-Y) and blue-minus-luminance (B-Y) information is transmitted in quadrature on a subcarrier with suppressed carrier at 3.579545 MHz. Analog TV channel's carrier frequencies may be offset slightly from one another to reduce the effects of co-channel interference in fringe reception areas.
