Mériol Lehmann

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.

dual-50-vga-cables-from-g5

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.

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.

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

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


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.

> 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.

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

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!

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.

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.

Dual 50' VGA cables from G5