• errer@lemmy.world
    link
    fedilink
    English
    arrow-up
    1
    ·
    edit-2
    10 months ago

    Not sure you follow: even if the primary frequency is out of range, a harmonic (half the frequency, quarter the frequency, etc) can simultaneously exist with the primary.

    • RightHandOfIkaros@lemmy.world
      link
      fedilink
      English
      arrow-up
      0
      arrow-down
      1
      ·
      10 months ago

      I suppose its possible with a low quality CRT that has poor construction, leaving loose parts or thin plastic fins that can vibrate at harmonics of a lower frequency, but high quality CRTs don’t have this issue.

      Extra or louder noise does not occur in normal operation of a correctly functioning flyback transformer circuit. Any frequency or harmonic (vibration) that occurs that is not the specified frequency of operation of the flyback transformer is caused by a problem in the circuit. A brand new CRT with known good parts will not have any kind of extra harmonic.

      I had to replace a flyback transformer because it was too loud, and it was a pretty simple job. Hardest part was finding a new flyback transformer. After replacement, the noise volume was reduced to normal levels.

      • rooroo@feddit.org
        link
        fedilink
        arrow-up
        1
        ·
        2 days ago

        Look, I know what I heard. And that was every old school screen I’ve ever encountered. What I don’t know is harmonic or flyback transformers.

        Maybe maybe it’s a ntsc vs pal thing? I’ll restate, I don’t know anything about the tech but I could tell if a screen was on.

        And before you restate that they were low quality: maybe every screen I’ve ever encountered was shit, yea. But then shit was the default apparently.