What is Analogue Television?
Analogue is the traditional way of broadcasting TV. Every little bit of information must be transmitted which takes up a massive amount of bandwidth and gives access to only a limited number of channels: BBC One, BBC Two, ITV1, Channel 4 and if available in your area, Channel Five.
Analogue television in detail
Analogue is the transmission of four elements of a television programme: picture, colour, sound and teletext; using different modulation schemes. The picture content is represented by the brightness of a single dot that is tracked across the screen in discrete lines with every point on every line represented by a constantly varying amplitude power level.
Every part of every frame must be transmitted, and whilst the picture quality can be outstanding, the signal takes up a lot of bandwidth. It cannot be compressed down to make room for other services and immediately shows even the slightest interference on the screen.
Analogue sound
The sound for analogue services is transmitted for UK terrestrial services in two ways. Firstly the mono signal is a frequency modulated analogy of the audio at a slightly different frequency to the picture. The stereo sound is transmitted simultaneously at yet another frequency by a digital carrier called NICAM.