Jason @ Hackszine writes –
If you’ve ever needed to place a VGA monitor further than the standard 6 foot cable allows, you may be familiar with some of these problems:
* VGA cables are expensive
* Several cables chained together affects signal quality
* Running a VGA cable through conduit is pretty difficult
You can avoid a lot of these problems by making a couple VGA to Cat-5 adapters. This will let you run standard, cheap, easy-to-pull ethernet cable between your computer and video display. The twisted pair helps reduce signal loss, though it doesn’t work quite as well as the long-run shielded VGA cables. Unless you need to extend your display to over 50 feet, this might be a much easier and more cost-effective way to do things.
16 thoughts on “VGA over Cat-5 cable”
Ouch; this is a terrible thing to do. The impedance is not correct and the noise you get will be unbearable for anything genuinely useful.
You can get VGA-over-cat5 baluns or even ‘KVM extender’ devices that do this problem justice fairly inexpensively. They generally do two important things to handle this problem more effectively: 1) Match the impedance of VGA to the UTP cable. and 2) Balance the signals to reduce noise.
Used this same diagram months ago to make mine. From computer, there’s a cable about 3′ long. One end is DB15 other is RJ45. There’s an RJ45 jack on the wall. Then a cat 6 run over about 20′ to the projector terminated with a DB15. Works perfectly great.
While it might work in a pinch, this will produce terrible RF interference and wipe out nearby radio and TV reception, not to mention interfering with DSL and probably audio equipment too.
Video cables need to be shielded.
Ebay has 50′ cables for under $20 shipped.
100′ for under $35 from the same seller.
over 100′ should use baluns over cat5.
I used this very diagram to build a 30-foot cable to connect my projector to an HTPC. Although obviously not as sharp as a shielded HDMI cable, it got the job done well enough to watch movies with quality equivalent to an S-Video connection. It also allowed me to play games on the projector screen. It is certainly cheaper than the 30′ VGA cables available from commercial vendors.
Nearby radio and video signals were not polluted. (The radio still worked, WiFi still worked, etc)
There is a slight moire pattern visible in the picture when the displayed image is a solid color. This noise is not visible during video playback.
has anyone tried shielded cat5e?
cause I need to run a projector about 150 to 200′ away.
if not maybe I will be the first..
If I go that route.
I’m rather interested in doing a similar thing with DVI-D signal, troublemaker is the narrow conduct. Anyone ever tried to rip up and successfully splice back a DVI-D cable? Any hints anywhere?
I just replaced a 10m ready-made VGA cable with this self-made cable in our Cologne Hacker Space. The picture is great now!
Before we had nice Web-2.0-shadow-effects which were acceptable for presentations (sorry Bre, that wasn’t an effect in our presentation-software for the Hacker Space Design Patterns), but while watching a movie they were really annoying. Now there is still a very light shadow when black hits grey (but not white) and you don’t see it on the first view.
So, thanks for this nice tutorial! :-)
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