The color composite video synchronous signal carries the luminance and chrominance information. Besides luminance and chrominance information, sync pulses are also part of the signal. These pulses ensure that specific lines for specific pictures in the TV signal are displayed properly: Horizontal syncs can be thought of as line breaks while vertical syncs indicate the beginning of a TV picture. A line consists of a horizontal sync pulse, indicating the beginning of a line. The color information is modulated onto a color subcarrier. A color burst is transmitted to allow recovery of the color information.
For radio transmission of the television signal, an RF carrier (vision carrier) is amplitude-modulated with the composite video signal. In order to save bandwidth, the lower sideband bandwidth is reduced (vestigial sideband transmission).
In contrast to the other existing analog TV transmission standards, the L standard is positively modulated. In the case of the L’ standard, the spectrum itself is inverted. The L standard was mainly used in France and in some states in Eastern Europe.