Lv 4
John asked in Consumer ElectronicsTVs · 4 months ago

Why is digital "static" different from analog static?

If an analog TV channel isn't picking up a signal it displays a snowy, noisy picture. A digital channel with no signal will just go blank. What causes this difference?

3 Answers

  • 4 months ago

    It isn't a matter of "static".    


    All digital TVs, and many analog ones, 

    are Programmed to display a blank raster instead of one that consists of noise.   

    Older analog TVs had no built-in video generator from which to obtain a blank raster, 

    which is why they display only noise.    

    By the way, approximately one percent of the noise you see when that happens 

    is "cosmic background radiation".   If you don't know what that is, look it up. 

  • khalil
    Lv 7
    4 months ago

    for an analog signal there is no threshold level but for a digital one there is so the level less than the threshold cannot be useful

  • Anonymous
    4 months ago

    Digital broadcasts are just a stream of digital information: a load of ones and zeros. 

    If that stream of information isn’t good enough then the digital receiver simply has nothing to translate into sound and pictures.

    But analogue broadcasts just display whatever they get. And if the only thing they get is the Cosmic Microwave Background radiation then you get static. The CMBR is an exceptionally weak signal and gets totally swamped by any normal analogue broadcasts.

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