[ale] Problem with monitor cord extension

[James P. Kinney III]

$40 for a 25' vga cable puts it in the low end category. If the monitor
frequency is low enough, it won't show the wavy line and jiggly stuff of
noise in the cable.  What the high end cables do is bundle the internal
wires like a bunch of tiny coax cables for the RGB lines. This is
similar to the Sun and SGI monitor cables, but without the mini RCA jack
connectors. 

Interference can come from a UPS as it has a large transformer that make
a big magnetic field at 60Hz. Also, high frequencies tend to "leak"
(they're not bounded by the wire, they have frequency/space domains that
are larger than the physical copper which is why they are often run in
coax).  You might be able to clean up the signal by repositioning the
cable. A poor mans coax can be made by wrapping the entire length of
cable with extra-heavy duty foil and tightly sealing the long seam down
the length of the cable and grounding the foil covering to the PC
chassis. It won't stop magnetic interference, but it will stop electric
field cross-talk for nearby wires.

On Thu, 2003-02-27 at 09:21, John Wells wrote:
> Interesting...exact one I have (except mine's the 6 footer).  It is
> running near a few other computers and a UPS...perhaps they're causing
> interference...
> 
> Thanks!
> 
> John
> 
> Geoffrey said:
> > John Wells wrote:
> >> Geoffrey,
> >>
> >> I'll do that.  Can I ask where you purchased the monitor cable?  Does
> >> it tell supported resolutions/frequencies? (mine doesn't).
> >
> > I've already trashed the packaging, so I can't check it out and don't
> > recall any specifics.  I did get it at Micro-center, I misquoted the
> > price earlier though, just found the reciept, it was $24.95.  It's a QVS
> >  VGA Monitor Extension cable, item #286112.  That's not really in the
> > cost range noted by others, since it's a 25' cable.  I've got it running
> >  in a horse shoe shape around my desk and it's running right with tons
> > of  other cables, so I would expect it must be a pretty decent cable.
> >
> >
> > --
> > Until later: Geoffrey		esoteric at 3times25.net
> >
> > The latest, most widespread virus?  Microsoft end user agreement.
> > Think about it...
> 
> 
> 
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> http://www.ale.org/mailman/listinfo/ale
-- 
James P. Kinney III          \Changing the mobile computing world/
CEO & Director of Engineering \          one Linux user         /
Local Net Solutions,LLC        \           at a time.          /
770-493-8244                    \.___________________________./
http://www.localnetsolutions.com

GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics) <jkinney at localnetsolutions.com>
Fingerprint = 3C9E 6366 54FC A3FE BA4D 0659 6190 ADC3 829C 6CA7 

 This is a digitally signed message part