The EM signal

The black and white video signal is basically as shown in the figure. It represents the brightness along each horizontal line, from white to black, with a small jump beyond black indicating a jump to the next line. The beginning of a new picture, that is the movement of the beam back to the top left hand corner, is indicated by a bigger jump beyond black. That is, the video signal is amplitude modulated but because of the need to represent more information every second, video signals require much more bandwidth than radio signals. For example the NTSC standard has 6MHz of bandwidth. What about the sound part of the television signal ? For analog TV this part of the signal is frequency modulated.