Pre-digital video or TV screen 'noise' due to no/poor signal?
Noise (video) Noise (video) Noise, in analog video and television, is a random dot pixel pattern of static displayed when no transmission signal is obtained by the antenna receiver of television sets and other display devices. The random pattern superimposed on the picture, visible as a random flicker of "dots" or "snow", is the result of electronic noise and radiated electromagnetic noise accidentally picked up by the antenna. This effect is most commonly seen with analog TV sets or blank VHS tapes. There are many sources of electromagnetic noise which cause the characteristic display patterns of static. Atmospheric sources of noise are
Digital signal advantages of digital signals for communications are often considered to be the noise immunity to noise capability, and the ability, in many cases such as with audio and video data, to use data compression to greatly decrease the bandwidth that is required on the communication media. A waveform that switches representing the two states of a Boolean value (0 and 1, or low and high, or false and true) is referred to as a "digital signal" or "logic signal" or "binary signal" when it is interpreted in terms of only two possible digits. The two states are usually represented by