PAL

PAL (Phase Alternating Line) is the predominant analog color broadcast standard in Europe, South Asia, Australia, Southern and Eastern Africa, and Eastern South America.

In the 1950s, when western European countries were planning to establish color TV, they were faced with a problem using the existing American 60Hz NTSC color standard: it would not fit the 50Hz AC frequency of European power grids. France's SECAM standard was one early solution. The PAL standard, unveiled in 1963, became the standard for the rest of Europe. The first PAL broadcasts took place in the U.K. and Germany in 1967.

PAL utilizes 625 lines per frame (576 visible lines – the rest being used for other information such as sync data and captioning) and a refresh rate of 50 interlaced fields per second (25 full frames per second). The audio speed for the PAL standard is also 25 frames per second, which is slightly faster than NTSC.

Phase Alternating Line describes how the phase of part of the color information on the video signal is reversed with each line; this automatically corrects phase errors in the transmission of the signal by canceling them out.

This article is licensed under the GNU Free Documentation License found at http://www.gnu.org/copyleft/fdl.html. It uses material from the Wikipedia article at http://en.wikipedia.org/wiki/PAL.

A map of standards in the 20th century. 21st century standards are changing to adopt digital broadcasts.