🚀 go-pugleaf

On Thu, 11 Sep 1997, Robert Bonomi wrote:
> In article <5v4683$h29@acme.sb.west.net> you write:

> >This doesn't make sense.  The same difference in magnetic field will 
> >result from turning a monitor with the screen facing north to the screen 
> >facing south (or east to west) in the same geographic location.  
> 
> "sensible" to you, or not,  it's _true_.  they're sensitive to the 
> longitude at which they're being used.  differing _vertical_ component
> of the magnetic field.  which, is -not- affected by the direction
> the monitor faces.  

I think you meant latitude.  Longitude would be a minor factor due to the
slight misalignment of the magnetic and rotational poles. Even so, the
vertical component of the earth's field is minor compared to the
horizontal factor except at the poles. 

> pick up your monitor, turn it upside down.  you'll see.

I would attribute any distortion that occurs in this case (nothing visible
with a rather heavy GDM1950 monitor facing south at 34N 120W) more to the
effects of gravity on the deflection components than on the vertical
component of the earth's magnetic field.  Note that I didn't try this with
the monitor turned on and it self-degausses on power-up, so there may have
been some effect that was not visible. 

In any case, it's probable that shipping a large, high-resolution monitor
any distance may require re-convergence regardless of the earth's magnetic
field, due to mechanical factors affecting the deflection components
within the CRT. such as the shadow mask or grid wires, electron gun
support structure, etc.  This is tedious, but easily accomplished with a
bit of patience and a suitable screen image such as a field of "+" marks. 

If the power supply is suitable, he shouldn't be more concerned about
buying a monitor shipped across the equator than one shipped the same
distance elsewhere. 

Now, about that whirlpool when you pull the plug out of the bathtub... :-)

--                   Jay Hennigan     jay@west.net              --  
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