magnetic shielding

On 30 Jan 2004 11:51:18 -0800, balaji@cheerful.com (Balaji) Gave us:

I hope it would be fine to ask this question here. Seeing you people
discuss this topic so furiously..., I remembered that my monitor shows
some sort of color fadings or such things when it faces East. In all
other directions, I have checked this myself. This is an LG
Studioworks 15" color monitor purchased in Feb 2002.
That is the magnetic field of the earth interplaying with your
aperture grill, offsetting the color, and convergences.
 
On Sat, 31 Jan 2004 02:59:01 GMT, "Sir Charles W. Shults III"
<nowayjose@planetpluto.com> Gave us:

"Balaji" <balaji@cheerful.com> wrote in message
news:aa481090.0401301151.2d135d93@posting.google.com...
I hope it would be fine to ask this question here. Seeing you people
discuss this topic so furiously..., I remembered that my monitor shows
some sort of color fadings or such things when it faces East. In all
other directions, I have checked this myself. This is an LG
Studioworks 15" color monitor purchased in Feb 2002.

The colors fade towards green but only on the top right corner of the
screen. I have observed that this effect disappears even for about
15-20 degrees change in orientation towards the North, but requires
much more change of orientation towards the South (45-50 degrees
perhaps) I used to wonder what causes all of this, but now from your
discussion, it appears to be because of the earth's magnetic field. Am
I correct?

Oh! and well, nothing significantly apparent happenned when I used the
degauss and change of refresh rates etc. that my monitor supports. In
fact I don't want to change the refresh rates at all since then Linux
causes some sort of a funny trouble then. Please do inform me.

Any object that can retain a magnetic field (such as ferrous metals or
the shadow mask of a CRT) can become slowly magnetized by the Earth's field.
When a television or video monitor is left in one position for an extended
period of time (from months to years), it becomes magnetized in a manner
that is parallel to the natural field lines passing through or around it.
When you rotate or move the monitor, now its field and the Earth's field
are no longer aligned and the colors will shift. Degaussing the monitor
usually cures the problem. If not, get a larger degaussing coil and do it
manually.
There are certain directional orientations in some regions of the
world that never allow a "cure".
 
In article <401ab04d$1@usenet01.boi.hp.com>, Bob Myers <nospamplease@add
ressinvalid.com> writes
"DarkMatter" <DarkMatter@thebarattheendoftheuniverse.org> wrote in
message
news:a3lj105thdodrseqnjn2oe83rm5i3718hq@4ax.com...
On Thu, 29 Jan 2004 10:55:42 -0700, "Bob Myers"
nospamplease@addressinvalid.com> Gave us:

Correct. Now, please leave responding to that question to
those who actually have experience and knowledge in this
area.

At the risk of interrupting the pleasant flow of conversation ;
The cause of wavy lines is the scan coil magnetic fields from one
monitor reaching another monitor . A magnetic screen is required that
has a high permitivitty to magnetic fields. (beware saturation if too
close)
I imagine highest quality monitors have such a screen built in.
Mine does not .
Most do not.
The cheapest solution would be to rotate the monitors for minimum fields
in the relevant direction.
Alternatively buy TFT monitors.
 

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