 white Video range 1,0 V Setup Reference Blanking black range Maximum sync Figure 16.3 Breakdown in time of a scan line. 4 Flyback is defined by the IEEE (Ref. 1) as "the rapid return of a beam in a cathode-ray tube in the direction opposite to that of scanning." Flyback is shown in Figure 16.1 where the beam moves left returning to the left side of the screen. TELEVISION TRANSMISSION black region. Beyond this region in amplitude is the blacker than black region, which is allocated to the synchronizing pulses. The blanking level (pulse) is shown in Figure 16.3. The maximum signal excursion of a composite video signal is 1.0 V. This 1.0 V is a video/TV reference and is always taken as a peak-to-peak measurement. The 1.0 V may be reached at maximum synchronizing voltage and is measured between synchro- nizing "tips." Of the 1.0-V peak, 0.25 V is allotted for the synchronizing pulses and 0.05 V for the setup, leaving 0.7 V to transmit video information. Therefore the video signal varies from 0.7 V for the white-through-gray tonal region to 0 V for black. The best way to describe the actual video portion of a composite signal is to call it a succession of rapid nonrepeated transients. The synchronizing portion of a composite signal is exact and well defined. A TV/video receiver has two separate scanning generators to control the position of the reproducing spot. These generators are called the horizontal and vertical scanning generators. The horizontal one moves the spot in the X or horizontal direction, and the vertical in the Y direction. Both generators control the position of the spot on the receiver and must, in turn, be controlled from the camera (transmitter) synchronizing generator to keep the receiver in step (synchronization). The horizontal scanning generator in the video receiver is synchronized with the cam- era synchronizing generator at the end of each scanning line by means of horizontal synchronizing pulses. These are the synchronizing pulses shown in Figure 16.3, and they have the same polarity as t