Thread: VGA over CAT5e
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Tomi Holger Engdahl Tomi Holger Engdahl is offline
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First recorded activity by BoatBanter: Oct 2008
Posts: 3
Default VGA over CAT5e

"philo" writes:

wrote in message
...
Hi Guys,

I need to get a VGA signal from the Nav Station in my boat to the
monitor in the bridge. I could just run a VGA cable (about 4m worth)
but I need to pass the cable through some small holes for the looming
(sp?) and the DB15 connectors wont fit unless I make the hole bigger.

I am thinking about running the VGA singal over CAT5e, which a Google
search seems to suggest is possible. I was wondering if anyone had any
better ideas, keeping costs fairly low.

Has anyone here had any success cutting the end off a VGA cable and
wiring on a new DB15 for example?

Thanks in advance,

-Al



VGA cable is shielded
and CAT5 is not, so you would get some horrible ghosting.


Thethe wrong cable impedance and lack of shileding between
RGB signals will not cause ghosting. Most ghosting will
be caused by the impedance mismatches.

The lack of shield in cable will cause that that cable
will pick up more easily external interference
and will radiate out more RF interference and properly
shielded VGA cable.


BTW, there may still be some ghosting even with VGA cable


True. The VGA cables vary in quality. The good ones are good
but there are also bad ones. One thing to keep in mind
in VGA connections is that it is a good idea to keep the
number of VGA connectors along the link minimum (ideally
only at source and destination), because the VGA connector
impedance is not exactly 75 ohms as the system is designed
for, and having many such wrong impedance connectors on
the way will cause impedanc mismatches that cause
reflections. For VGA cables is best to use a correct
length cable in the beginning, and avoid using
orignal cable + extension cable combinations.


--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/