Just how far can you push a video signal?

[dokeo]

Greetings! I'm working on a video project for my church. They are working on installing two video projectors so that we can see the stained glass (which is currently covered up by the center screen). In working on a holistic solution, the question came up of just how far you can push a video signal.
* SVGA?
* S-Video?
* RCA?
* Cable (F-connector)?

I see that there are amplifiers as a way to accomplish the goal ... what I'm not seeing is what the maximum rates are for the various kinds of transmissions/connectors. This would be critical to know, as I won't need to boost the signal if the distances are less than 150 ft.

Thanks for any help you can provide regarding this issue!

[Jonathan]

SVGA can usually go about 100 feet without a booster.  If you use a balun (an adapter that will run the signal over CAT5e ethernet cable) you can get it up to 500 feet or so.  S-video and RCA are about the same situation.

The standard Coax cable connection can be run about that far also, but you can run into problems if you've split the connection anywhere without an active splitter.

The video baluns work very well for getting the signal far.  Especially because the CAT5e cable is much easier to run than the vga cables or other cables.  You can check out some of the baluns here:

VGA Balun sender with audio
VGA Balun reciever with audio

VGA balun full set for up to 550 feet

S-Video Balun (you would need 2 of this unit)

RCA Balun with audio (you would need 2 of this unit)

[mark]

Since they are all analog signals, there really isn't a definite limit on the cable lengths.  The signal will generally get through, but over a long run it might lose some clarity or appear a little faded or dim.  Most of the time, with projectors or TV's the loss isn't enough to notice on the screen, and unless you compare the same screen side by side with a short run no one will notice.  Especially if you are using simple or large images.

Other factors can also lead to quality loss: poor quality cables, too many connectors or a lot of electrical interference can make a signal terrible quickly.  Here are some pointers

• Avoid using couplers to daisy chain a lot of short cables together.  Usually the wire gauge/constrution on short cables is not meant to support long runs, where a single longer cable will have thicker or shielded wired.
• Simple analog signal splitting (without a booster) effectively cuts your signal in half.  Keep that in mind.   Boosted splitters will often be labled as powered or distribution amplifiers.  A boosted splitter will not usually show any signal loss, and can help keep the singal strong over long runs.  In my opinion they are almost always worth it.
• It's great to look for a good deal on a cable, but if something looks too good to be true, it probably is.  (I have heard of video cables selling for under a dollar on ebay)  There is definitely a mark up for brand names in cabling, so you have do decide if the name is worth the price to you, but at least make sure you are getting your items from a reliable vendor with a return policy etc.
• Electrical interference usually comes from other electrical devices or power lines.  If you are running wires in walls, ceilings or crawl spaces, avoid running closely parallel to power wiring, and watch out for things like data closets, AV racks and microwaves.  They can dump off a lot of interference.
• ALWAYS ALWAYS test your cables before using them in a complicated install.  Even premium cables can show up DOA and you don't want to have something run through walls and ceilings only to find out it needs to be replaced.