why do some TVs show static when there’s no signal?



why do some TVs show static when there’s no signal?

In: Technology

These are analog signals coming in over the air or cable. A TV takes a very specific analog signal and converts it into something you see and hear. If there is no specific signal, just background noise, then it will display that background noise, which is the static you see.

TV receivers have to pick out packets of information from a certain level of background noise (constant interference from other technology in the area). To do this, it looks at the difference in amplitude between good signals and bad signals.

When the signal is weak, it is more difficult to distinguish good packets of data from random noise, and so more bits of noise end up slipping into the signal that ends up on your screen. When there is no signal altogether, it simply shows you the ambient noise the receiver is picking up, amplified to a level that your decoder is able to read and display.

They are getting a signal; anything the antenna picks up. When you’re not tuned in to a specific channel that’s designed to display on your TV, it’ll show all the random noise it’s picking up instead.

In fact, it’s estimated about 1% of the static on your analog television is background radiation left over from the Big Bang!