On Wed, 7 Apr 2010 00:54:07 +0100, "Arfa Daily"
wrote:


"mm" wrote in message
news
Question 1: On a tv screen, what is the opposite of pin-cushioning
called?


In the UK, we always called it "barrel distortion"

And here to it seems. Now I can tell all my friends I have barrel
distortion. They may not care, but I will enjoy saying it. At least
to one or two people.
....
I thought it was dirt on the screen, somehow, but it's inside the
glass. It's visible when a tv show is on, when there is no signal to
the tv, and not visible when the tv is off.

I don't have much expectation of fixing this, but I would like to know
what it is, how it can happen.

What we used to call "striations" maybe ?

Even when there is oonly two vertical lines? Oh, yeah, that's exactly
what you say below.

Caused by velocity modulation of
the scanning beam, and was often due to the damping resistor across the H -
linearity coil either burning out, or running so hot that it crystalised its
solder joints. Without this resistor in place and working, the lin coil
'rings' a couple of times after the 'shock' of flyback,

That sounds right. Ringing, and right after it gets zapped back to
the left side.

This is close that it's probably enough to fix it. And I might be
able to find the H-linearity coil without buying an expensive set of
notes, so maybe if this gets worse, I'll save the tv instead of
throwing it away.

Do you want at the proper value for the damping resistor? If it's
been running hot, I probably can't tell.

and produces a
couple of vertical lines similar to what you describe, in about that sort of
position.

Arfa