Editing Colorburst (section)

== Explanation ==

In [[NTSC]], its frequency is exactly 315/88&nbsp;= 3.579{{Overline|54}}{{Efn|name=repeating decimal|[[Repeating decimal#Notation|Repeating decimal notation]]}}&nbsp;[[MHz]] with a phase of 180°. [[PAL]] uses a frequency of exactly 4.43361875&nbsp;MHz, with its phase alternating between 135° and 225° from line to line. Since the colorburst signal has a known amplitude, it is sometimes used as a reference level when compensating for amplitude variations in the overall signal.

[[SECAM]] is unique in not having a colorburst signal, since the chrominance signals are encoded using [[Frequency modulation|FM]] rather than [[QAM]], thus the signal phase is immaterial and no reference point is needed.