100 ft. vga image redish

[parapa05]

At our church we had this setting:
HP multimedia computer with RCA out ( video card) so I had cable running from the comp. to the splitter to 3 monitors, image was good but not very clear we thought to update computers.

Last week we order 100ft VGA cable ( 2 more cables 1-50ft and 1-25fh):
Amazon.com: RiteAV - SVGA Monitor Cable - 100... a splitter:
Amazon.com: Cables To Go 29550 UXGA Monitor...
Problem is that the 100ft cable when connected to the projector it comes out redish/purple kind of colour and the image is not very clear , the RCA seems better.

the cable runs through the attic and cannot understand what the reason for the results any ideas please help?

Before cable went up the attic we tried it and not problem it was clear.


Thank you

[ruikuanli]

Does your splitter has a signal booster feature? it seems the cause of the inclear images is because of signal drop from your computer going to the monitors.

[parapa05]

it seems based on Amazon's that it is just a splitter

[parapa05]

The new computer we have has HDMI out also, would it be better than vga for that distance 100ft? OR would you say with the vga we have instead of 100 get two 50 and connect to amplifier?

[Brad Weber]

First, try connecting the cable going to the projector direct to the computer output and see how that looks. Also check all the connections, maybe even jiggle them a bit to see if anything changes.

Next, look at the cable run in the attic. Does the cable run over lights or parallel to power runs? Does it run near or on any other equipment? Also make sure the attic space is not used as a return air plenum as I don't believe that cable is plenum rated.

You might want to make sure that the resolution and scan rate you have set for the computer is supported by the projector, the projector manual will usually list the supported resolutions and scan rates. This wouldn't usually cause the color aberration noted but is a good thing to eliminate as a possibility.

Also related to resolution and bandwidth, it is odd that the cable is marketed specifically as a "SVGA" cable rather than the often more generically applied "VGA" label. SVGA generally referred to 800x600 resolution graphics and the original version to 16 color graphics, although I think 256 colors was also considered as SVGA. Pure assumption but that may indicate that the cable uses smaller conductors or similar that would relate to greater losses for higher bandwidth signals. It's probably a good guess that you are running a higher resolution and number of colors than that, which the cable may not really be intended to support.


HDMI would actually be a poor choice for a 100' run as it is intended to run short distances, generally 30' or less. You would probably have to use an expensive cable, use HDMI-to-UTP/CAT converters, add one or more repeaters inline in the run or similar

[VoltNHalf]

The other thing that strikes me is the color seems to be missing one element (thus the reddish/purplish color). I had this happen once on a projector after a lighting strike - it fried one of the VGA color leads inside the projector. It's possible there may be a broken wire or damaged pin somewhere in your setup. Wouldn't be the first time that's happened during a cable install.

[parapa05]

Brad Weber "First, try connecting the cable going to the projector direct to the computer output and see how that looks. Also check all the connections, maybe even jiggle them a bit to see if anything changes."
- Before I went up in the attic, I tried it and it did work not problem.
Brad Weber "Next, look at the cable run in the attic. Does the cable run over lights or parallel to power runs? Does it run near or on any other equipment? Also make sure the attic space is not used as a return air plenum as I don't believe that cable is plenum rated."
- I do believe that must be the problem, in this case what type of cable would you suggest?

[Tekguy]

Your problem may be a degraded signal try a splitter amplifier such as http://www.monoprice.com/products/pr...t=1#largeimage

[Brad Weber]

Originally Posted by parapa05

Brad Weber "Next, look at the cable run in the attic. Does the cable run over lights or parallel to power runs? Does it run near or on any other equipment? Also make sure the attic space is not used as a return air plenum as I don't believe that cable is plenum rated."
- I do believe that must be the problem, in this case what type of cable would you suggest?

The first step would probably be to try to physically separate the cabling, getting the cable to be a few feet rather than a few inches from a parallel power run, lighting ballast, etc. can make a significant difference. So can crossing power lines perpendicular to them rather than running parallel.

VoltNHalf also brought up a good point, it is all too easy for cables to be damaged during installation without realizing it, in this case perhaps incurring some damage to the green conductor and maybe even one of the sync conductors.

If you can't move or adjust the existing cable to get an acceptable result or the cable needs to be replaced then you might want to look at a VGA over CAT solution, there are many of them out there and the twisted pair construction of the CAT/UTP cable combined with the differential input for the twisted pairs should make them much more resistant to any interference.

If you are using the splitter/Distribution Amplifier you initially noted than while the gain is not identified the statement in the product literature that "It boosts your high resolution video signal up to 210 ft." suggests their is some gain applied in that device and that a 100' run should be well within the claimed capabilities for signals up to 2046x1536 at 50Hz, 60Hz or 75Hz refresh rates and up to 1920x1440 at 80Hz refresh.

[parapa05]

I just want to thank all for reading this posting, the issue has been resolved!!!!!! not sure what the problem was, I think I may still get an amplifier ot something to give a bit of a bust to the signal ( like the one mentioned in on e of the replies).
I think the issue was on the projector's settings.