SECAM
SECAM is an analog colour television system first used in France. SECAM can also be found in parts of Greece, Eastern Europe, Russia, Africa and a few other parts of the world.
SECAM differs from the other colour systems by the way the R-Y and B-Y signals are carried. Firstly, SECAM uses frequency modulation to encode chrominance information on the sub carrier. Second, instead of transmitting the red and blue information together, it only sends one of them at a time, and uses the information about the other colour from the preceding line.
Because SECAM transmits only one colour at a time, it is free of the colour artifacts present in NTSC and PAL resulting from the combined transmission of both signals.
