Broadcast television systemsBroadcast 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 the International Telecommunication Union (ITU) in 1961, with each system designated by a letter (A-N) in combination with the color standard used (NTSC, PAL or SECAM) - for example PAL-B, NTSC-M, etc.). These analog systems for TV broadcasting dominated until the 2010s.
405-line television systemThe 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. The number of television lines influences the , or quality of the picture. It was introduced with the BBC Television Service in 1936, suspended for the duration of World War II, and remained in operation in the UK until 1985. It was also used between 1961 and 1982 in Ireland, as well as from 1957 to 1973 for the Rediffusion Television cable service in Hong Kong.
NTSCThe first American standard for analog television broadcast was developed by the National Television System Committee (NTSC) in 1941. In 1961, it was assigned the designation System M. In 1953, a second NTSC standard was adopted, which allowed for color television broadcast compatible with the existing stock of black-and-white receivers. It is one of three major color formats for analog television, the others being PAL and SECAM. NTSC color is usually associated with the System M.
Analog televisionAnalog television (analogue television) is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes snowy and subject to interference.
