Burst phase is the first ten
cycles of
colorburst
Colorburst is an analog video, composite video signal generated by a video-signal generator used to keep the chrominance subcarrier synchronized in a color television signal. By synchronizing an oscillator with the colorburst at the back porc ...
in the "porch" of the synchronising
pulse
In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the nec ...
in the
PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
(Phase Alternation Line)
broadcast television systems
Broadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals.
Analog television systems were standardized by ...
format. The frequency of this burst is 4.43361875 MHz; it is precise to .5 Hz, and is used as the reference frequency to synchronise the
local oscillator
In electronics, a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. This frequency conversion process, also called heterodyning, produces the sum and difference frequencies from the frequenc ...
s of the colour decoder in a PAL
television set
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
.
This colorburst is sometimes called a "swinging burst", since it swings plus or minus 45 degrees line by line (hence the expression "phase alternating line"). This swing is used to set the centre frequency of the colour reference oscillator in the decoder. The swing of the burst phase distinguishes PAL from non-PAL lines, and produces the IDENT signal.
Television technology
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