Video over Cat5 Extenders

[Duo]

Interesting that they say to use STP. VGA uses unbalanced signals and so STP is not really any better than coax. In fact, I'll bet you could get very good quality by using separate runs of 75 ohm TV coax (VGA uses 75 ohm termination) and make sure the connections are solid and shielded.


As far as converting to digital, you'd need a very fast high bandwidth convertion system. The three video lines need to work up into the megahertz.

[Garbz]

Using coax lines begins to add bulk. And I simply cringe at the thought of terminating 5 lines of 75ohm coax to a DB15 plug

[cbm5]

It's simpler and cheaper to just use a VGA cable that already has the separately shielded cables inside. Just searching eBay for "vga cable" brings up a lot of options. Like 50-foot triple shielded VGA extension cables, 2 for $35.

[ringram]

you can use cat-5 cable, but the impeadance mismatch is what is causing the ghosting (signal reflections).

Like it was stated in a previous post, buy the proper cable, ie: one that has coax for each colour. For a long run, it is well worth it if you want to maintain a quality image.

As far as the VGA drivers, for the most part, the amplify the signal to drive the long cable runs. Look up EXTRON, we use these at work for long runs.

[Garbz]

Hmmm i thought all vga cables were the same crap that's in the monitors. I'll look into it.

[gilfo1]

Hey Guys,

I am glad I found this post. I was getting ready to spend money on a cat 5 extender ( and I only need to extend a computer monitor about 30 feet... )

I will probably go the 3 - 75 ohm coax wire route ( plus sync ).

Just wondering how the termination is actually wired...

I assume coming from a newer computer video card, I don't need termination on the source?

But how do I wire the destination? I can find the pinouts online, but is the 75 ohms before I "tap" the signals, or after, and is the resistor between the "hot" and ground?

I just don't get how to wire the terminations...

Thanks for your help guys.

Regards,

Luke

[Bricolo]

400ft is a long distance for a video signal.

Unfortunately I see no cheap solution.
I have some work esperience as an audio-visual technician, and when we had to install video hardware on such distances:

-convert to optical
-convert to ethernet
-use a RGBHV signal on 5 lines, with a heavy cable (sorry I forgot the exact reference) around 4cm in diameter, it's made of 5 VCB75 or VCB100 coax cables.

As Ringram said, Extron is good stuff, Kramer also makes good products.