On Feb 8, 4:16*pm, "William Sommerwerck"
wrote:
No offense, but why should a degausser work, when a bulk tape eraser
with the power to handle metal-particle tape doesn't? You have to stand
about 8' from the set before the bulk eraser's effect is no longer
visible.
The inductive kick when the eraser was shut off is quite large.
If you bring the bulk eraser to the same location as before, can you
see any effect on the picture? If you can, try turning it on and move
it slowly away to several feet before shutting off.

Are you kidding? grin The bulk eraser has a huge effect.

My approach has been to follow the standard procedure -- bring the
demagnetizer near the set, then slowly back away to let the flux gradually
decline, until there is no visible effect on the image. This does _not_
remove the splotch.

I would take a very strong magnet, such as from an old magnetron,
bring it near to the TV, in the same place as the eraser was when you
shut it off, and then rotate the magnet rapidly while slowly moving it
away from the TV. It effectively reverses the magnetism back and
forth while slowly reducing the strength. That will clear many problems
in my experience. I have a dozen old magnets from scrapped uwave
ovens, they are about the strongest I can find except for magnets
from very large loudspeakers and are so strong you don't want
your finger between two of them.

How is this approach different from slowly moving a degaussing away from the
CRT? Is the magnetron magnet significantly stronger than a degaussing coil?
(The implication of what you wrote is that it is.)

Zenith used to make a bar magnet on the end of stick. You started the magnet
spinning (by hand), then pulled it away from the CRT. The idea was to clear
small splotches of magnetism.

Somebody suggested that I had damaged the aperture grille. Is this possible?
Does anyone know?

Back in 2006, a friend helped me disassemble one of my Apogee speakers
(which has lots of magnets). The speaker came rather close to the set, and
for a few minutes the splotch was gone. (And, no, the speaker is not the
cause of the splotch.)

OK - what I would try next is turning the bulk eraser on and off in
the same position that it was when you caused the problem, to see what
happens. If it was the bulk eraser that casued the problem, something
should change. If nothing changes, then maybe there is something else
magnetized somewhere else in the set. Is it possible something got
magnetized and then moved so that it is no longer affected by the bulk
eraser? Have you pulled the back to see if anything seems out of
place?

Bob Hofmann