Dual 50' VGA cables from G5

May 31, 2006 at 2:34am

Dual 50' VGA cables from G5

I have two computers, a G4 dual 1.25 and a G5 dual 2Ghz. I have 50′ VGA cables from both video outputs on each Mac going to 4 video projectors. I’m only able to have one video signal going out from each Mac. When I go to the displays preferences and click on “detect displays”, the second projector goes yellowish for a couple of seconds and then goes away. With the G5, the other projector is fine when I do this. With the G4, both projectors disappear.

Could it be possible that there’s not enough power to drive both VGA with 50′ cables with a single video card? And if yes, are you aware of a VGA booster or do I have to put another video card to make it work? Note that I already have an AlchemyTV inside each computer for live video feed.

#26223
May 31, 2006 at 2:56am

if the quality cable is poor, you may very well need a VGA
distribution amplifier for a run that long. I dont know the VGA spec
off hand, but shoddy cables dont run well, and VGA is analog, so
longer distances mean poorer signal quality. Id test with shorter
cables before ruling anything out though.

v a d e //

http://www.vade.info
abstrakt.vade.info

#78000
May 31, 2006 at 4:10am

I use Extron VTT-001 converters (from VGA-ethernet cable for long
runs) Cheaper and better in the long run.

http://www.extron.com/product/product.asp?id=vtt001

#78001
May 31, 2006 at 4:24am

no pun intended ;)

v a d e //

http://www.vade.info
abstrakt.vade.info

#78002
May 31, 2006 at 12:44pm

Ha! I just can’t help it.

#78003
Jun 1, 2006 at 1:42am

Thanks guys, I finally managed to get things working. I bought a DVI to composite adaptor and replace one of the VGA cables with a coaxial cable. The more I think about it, the more I think the problem was elsewhere than the cables’ length.

#78004
Jun 1, 2006 at 1:53am

> Thanks guys, I finally managed to get things working. I bought a DVI to composite adaptor and replace one of the VGA cables with a coaxial cable.

Ouch! That’s really going to cost you in terms of quality.

wes

#78005
Jun 1, 2006 at 11:58am

Yes, I know but the opening is tonight and I don’t have time to mess around more. I planned 5 days for the installation and the guy at this gallery in Toronto rented the space to a condos promoter for a dumb promo (buy a loft, we’ll give you a painting!) after we had an agreement…So we had limited access to the space and I have to do with that!

#78006
Jun 1, 2006 at 12:56pm

I don’t think the quality loss has to be an issue if you use proper BNC cables. In all major productions where video has to be sent to large projectors or led-screens, the video crew asks us for composite.

Now that you are talking about digital to analog video conversion: does anyone have a good advise for zooming in on a videocard output other than using an (expensive and still crappy) scan converter? Did any of you try the Trust Televiewer 1610 RC? I guess I am looking for something like that but with (much) higher quality.

Thanks,
Mattijs

#78007

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