Media alt text:
3D render of old tv set with animated static on its screen, as if tuned to a dead channel.

  • jeffw@lemmy.world
    link
    fedilink
    arrow-up
    39
    arrow-down
    1
    ·
    edit-2
    8 months ago

    Waves are everywhere. The TV picks up whatever waves it can. Some of those waves are signals meant to transmit an image (eg from a broadcast tower), others are just random noise in our environment.

    Not an expert, but that was my understanding

    • ALostInquirer@lemm.eeOP
      link
      fedilink
      arrow-up
      3
      ·
      8 months ago

      It’s been awhile since I’ve messed about with this, so I don’t remember (and you may not either, so this is an open question), but wouldn’t it produce the effect even if disconnected from an antenna?

      If so…Would the same principle be in play of it picking up on general EM waves to cause the effect?

      • lurch (he/him)@sh.itjust.works
        link
        fedilink
        arrow-up
        10
        ·
        8 months ago

        the effect can change slightly if you unplug or touch the antenna or the TVs socket for it, because it may change what contributes to the signal noise and how much. It can for example become brighter and the pitch of the audio noise can change.

      • algorithmae@lemmy.sdf.org
        link
        fedilink
        arrow-up
        8
        ·
        8 months ago

        Yeah, the same way a radio tuned to a station could be static until you plug in an antenna.

        You could also get hums and interference from other sufficiently strong EMF sources, like how AM radios can pick up the sound of transmission lines

        • dohpaz42@lemmy.world
          link
          fedilink
          English
          arrow-up
          8
          ·
          8 months ago

          Your mom (or dad) using an electric knife to cut a turkey on thanksgiving would do the same. It was wild.

        • lemmy689@lemmy.sdf.org
          link
          fedilink
          English
          arrow-up
          4
          ·
          8 months ago

          AM car radio can pick up the waves from your cars electrical alternator as well, which can cause the static to rise and fall in pitch as you speed up and slow down.

      • Kalkaline @leminal.space
        link
        fedilink
        arrow-up
        1
        ·
        8 months ago

        The display on the screen is the strongest signal. Without a strong signal from a TV tower, you just get noise from 60 Hz AC running through the wall, or radio towers, or power lines, or whatever else makes that radio noise.

      • BarqsHasBite@lemmy.ca
        link
        fedilink
        English
        arrow-up
        1
        ·
        8 months ago

        Afaik the antenna is picking up the background waves/radiation and the TV is displaying that background waves/radiation. If you disconnect the antenna, the TV will have no signal to display, it’ll be as blank as it can get.

        • linearchaos@lemmy.world
          link
          fedilink
          English
          arrow-up
          1
          ·
          8 months ago

          Nah, the antenna is tuned to pick up vhf/uhf, but the wire / traces and even the legs of the amplifier are sufficient to pick up cmb