Squealing CRTs

From: Iggy Drougge <optimus_at_canit.se>
Date: Thu Oct 4 10:08:11 2001

Tony Duell skrev:

(I'm a bit late in replying since I've been waiting for the terminal to lose
its charge before opening it up)

>> Heller to everyone and Tony. ;-)

>Yet again I'm a nobody. Well, if I'm not in the set of 'everyone' I must
>be, right :-)

It's comme-il-faut on this list by now, what is one to do?

>> What do you do about a squealing CRT? I've got this nice terminal which i=

>I've never heard a CRT squeal. I've heard one hiss, but that was when the
>pinch-off tube got cracked and the vacuum was leaking out. That effect
>only lasts for a few seconds, and then the owner starts squealling as he
>has to look for a replacement CRT.

>The squeal from most monitors/TVs comes from the flyback transformer
>(horizontal output transformer, line output transformer, call it what you
>will). THe core vibrates at the horizontal scan frequency.

Is that the neck at the back of the tube? I see a key-like screw protruding at
a 90? angle from the neck, which seems to be coupled to a metal band wrapped
across the neck.

>The cure is to make sure the core can't vibrate. If there are clamps on
>the core, tighten them (not hard enough to crack the core of course. If
>not, then often a squirt of hot-melt glue around the core and windings
>will silence it, but don't blame me if it ruins the transformer.

There is a big squirt of glue around the mountain of wire (what you call a
coil, I think) where the neck begins.

>> s
>> working, but it emits a high-pitched whine which is not only unpleasant a=
>> nd
>> annoying, but quite scary, too. It feels as thoughit's going to blow in y=
>> our
>> face any minute.

>Don't worry about that. THis effect has not other consequences (other
>than annoying sound)

That's a relief.

En ligne avec Thor 2.6a.
Georgie beundrade stor?gt sin pappa som med v?ldsamma slag gick l?s p? det
stora tr?det. Han badade i svett, och den muskul?sa kroppen bl?nkte i
solskenet. Hon ?lskade honom.
    Lady Georgie, TMS 1983
Received on Thu Oct 04 2001 - 10:08:11 BST

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