Q. Show television waveform?
The television waveform representing one scan is illustrated in Figure. A blanking pulse with a duration of 0.18 of the horizontal - sweep period Th is added to the visual voltage generated by the camera. While the blanking pulse turns off the electron beam in the receiver's picture tube during the horizontal retrace time, an added sync (synchronization) pulse helps the receiver to synchronize its horizontal scanning rate with that of the transmitter. Also, a burst of at least 8 cycles of 3.579545 MHz, called the color burst, is added to the "back porch" of the blanking pulse for synchronizing the receiver's color circuits. The visual information fluctuates according to the image between the "black level" and the "white level" set at 70.3% and 12.5%, respectively, of the peak amplitude. An array of various sync pulses are added on top for both horizontal and vertical synchronization purposes.