Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Emil Barnabas]

I do a lot of portable A/V projection and use the Gefen ex-tend-it CAT5-1000. It extends VGA up to 330 feet via one CAT5 cable.

http://www.gefen.com/kvm/product.jsp?prod_id=2294

This unit was actually designed to allow you to put your noisy computer in a seperate room from your computer monitor, mouse, and keyboard, but it works great as a way to get VGA to a remote projector.

Gefen makes a lot of products that extend signals a long way.

And as mentioned earlier, use a switcher/scaler to convert your video to VGA and just have one video signal going to your projector.

[Philip Cain]

Buy a shielded VGA cable that is long enough to meet your needs. If the run is 100', go buy a 150' cable. You shouldn't compromise if this is an installed system (which, if you are crawling through attics, it apparently is).

And I wholeheartedly agree with Aaron, don't switch the signal at the projector. Run a single VGA out of a switcher/scaler, and run your various video/computer signals into the switcher/scaler. You'll appreciate the distraction-free switching.

You might want something like this: http://www.ivojo.co.uk/extron-mps-112.htm

[Brad Weber]

There's a reason that major manufacturers don't make 150' VGA cables and using one would be a major compromise.  You can get a 100' VGA cable, but even then I wouldn't be too optimistic about the results.

Look at the chart on Page 2 of the following: http://www.westpenn-wpw.com/pdfs/broadcastvideo.pdf.  Most of the pre-manufactured VGA cables use (5) miniature 26AWG cables.  At a typical XGA resolution that's a recommend run of less than 40'.  These are recommended numbers and are not absolutes, but for 100'+ runs you would really want to use individual RG-59 runs and not a premade VGA cable.  

[Gary D.]

I'm running into the same issue of getting the signal to the projector (in my case it's multiple projectors and LCD monitors).  In the case of using CAT-5 wires with the appropriate adapters, is there any noticable delays with the signal?  We try to broadcast live throughout the church during the service, but have issues with signal quality and delay.  This is because we are currently doing it using a s-video camera output split all different cheezy ways and then using these Leviton S-video to Cat5 adapters (they really aren't adapters, more like a s-video with a punchdown in the back for cat5).

Also, what are your church's wired for? S-Video, RGBHV, component, composite,???  I feel that our projectors and LCD monitors are being under-utilized if they are fed s-video.  We are using MediaShout, DVD's, s-video, and eventually 720i video.

[Emil Barnabas]

I do not see any delay using the Gefen unit I mentioned.

I once ran a composite video signal from a camera at the back of the audience through 100 feet of microphone cable (http://barnabas.com/sound/cables/index.shtml) to a scalar that converted it to VGA. This VGA signal went through about 25 feet of VGA cable to a projector (rear projection). Then the VGA output of that projector went into the Gefen unit to send the video over about 75' of CAT5 cable to the second projector.

Standing in the audience looking at both screens, I could not see any delay in the signal between the two projectors.

[Brad Weber]

Emil Barnabas wrote on Wed, 03 January 2007 21:43

I do not see any delay using the Gefen unit I mentioned. I once ran a composite video signal from a camera at the back of the audience through 100 feet of microphone cable (http://barnabas.com/sound/cables/index.shtml) to a scalar that converted it to VGA. This VGA signal went through about 25 feet of VGA cable to a projector (rear projection). Then the VGA output of that projector went into the Gefen unit to send the video over about 75' of CAT5 cable to the second projector. Standing in the audience looking at both screens, I could not see any delay in the signal between the two projectors.

That's somewhat irrelevant, as the issue would really be any delay between a direct video signal and the first projector in your application.  What you really needed to do was compare an image direct off the camera to what was on the projectors.  Delay is probably not an issue, but image quality probably is.

I have to ask if you simply have some aversion to video cables as it seems like you went through a lot of effort, and likely some noticeable image quality reduction, that could have easily been avoided.  Using a mic cable for video and converting to CAT5 for a 25' run and then again for a 75' run just seems to make little technical or financial sense.

[Ole Anderson]

I am considering a CAT 5 solution to getting signal to 2 projectors, over 100 feet thru exist conduit.  Can someone give a definitive answer regarding signal quality loss?  Will it be noticeable to the average person?  XVGA.  DVD and Easy Worship plus possible Power Point.

[Emil Barnabas]

Brad Weber wrote on Thu, 04 January 2007 15:23

That's somewhat irrelevant, as the issue would really be any delay between a direct video signal and the first projector in your application.  What you really needed to do was compare an image direct off the camera to what was on the projectors.

In my application, how does a delay between the camera and the first projector determine the delay in the CAT5 solution that was between the first projector and the second projector? I saw no delay between the two projectors, which seems to indicate that the image going into the CAT5 solution experienced no delay getting to the second projector.

I did not see any delay between the live person on stage and their image on the screen, which means that my microphone cable solution did not introduce any delay either.

Brad Weber wrote on Thu, 04 January 2007 15:23

I have to ask if you simply have some aversion to video cables as it seems like you went through a lot of effort, and likely some noticeable image quality reduction, that could have easily been avoided.  Using a mic cable for video and converting to CAT5 for a 25' run and then again for a 75' run just seems to make little technical or financial sense.

Have you tried it? I usually get very good quality signal running video through mic cables. I do not do enough video work to justify buying a long coax cable. It makes financial sense to me to use cables I already have rather than to buy an expensive cable I might only use a few times that will not significantly add to the quality of the signal.

[Brad Weber]

Quote:

In my application, how does a delay between the camera and the first projector determine the delay in the CAT5 solution that was between the first projector and the second projector? I saw no delay between the two projectors, which seems to indicate that the image going into the CAT5 solution experienced no delay getting to the second projector.

My mistake, for some reason I took it that you used CAT5 conversion for the other runs, but looking back that seems to be an incorrect understanding.

Quote:

Have you tried it? I usually get very good quality signal running video through mic cables. I do not do enough video work to justify buying a long coax cable. It makes financial sense to me to use cables I already have rather than to buy an expensive cable I might only use a few times that will not significantly add to the quality of the signal.

I can't say that I have tried this, since the different cables are designed to optimize transmission and shielding for the related signals and frequencies, I use microphone cable for microphone signals and video cable for video signals.  You developed a creative solution and should be commended for that, but I would consider it more a temporary solution and not a recommended standard approach.  I believe that using mic cable for a run of that length would affect the image quality unless the signal quality was low to start with.

However, my comment was actually based on several observations.  First, simply using a video cable would seem to be much easier and not that much more expensive than using a microphone cable and all the necessary adapters.  Second, using CAT5 conversion rather than direct cabling to go between two projectors in the same room is unusual unless there is some physical constraint prohibiting standard cabling, which did not seem to be the case.  Finally, in a project incorporating a camera, scaler, two projectors, CAT5 converters and some RGBHV cabling, using mic cable for the camera video seems to be at odds with the rest of the system and having a real video cable for the camera would seem both appropriate and a small expense for this application.  These all seemed to point to an attempt to avoid video cabling, but it may simply be a matter of using what you had on hand rather than investing in what at least seems more appropriate to the application.

[Emil Barnabas]

For a permanent install, I definitely recommend using high quality cables designed for that particular application. For a one-time event, you might be able to get by with a cheap substitute.

Back to the original post, 100 feet of high quality VGA cable should work fine.

[ProSoundWeb Community]