I’m preparing to run some video/computer cables from my entertainment center to a ceiling mounted projector. I plan to have composite video, S-video, component video and S-VGA connectors for the projector.
While looking at the local Home Depot, I was checking out the modular wall plates with plug-in connectors for audio/video/computer applications. They have modules for RCA and S-Video connections which are designed to be used with Cat5e cable. The RCA connectors can be wired with either 1 pair or 2 pair for increased signal quality, according to the product description.
I’m not too worried about the composite video and S-video, but I’m concerned whether this type of interface would maintain the quality for the component video signal. BTW, the distance would be less than 25 feet.
Has anyone had experience with this kind of application, or know enough about the specs to tell me if I would be OK using these?
Why would you want to do this?
Cat5e cable and RG2 Coax cable cost pretty the same price in bulk (10-15¢/foot). And coax cable will work better for video signal. Plus having different cable types makes it easier to keep wires straight when installing them.
I suppose that last item could explain this.
You might want to do this because you want to have only 1 type of cable to work with. Then you only need one set of tools for working with that cable, and only have to learn one way of making connections. And you might save a bit of money, since you could buy only a large spool of cat5e cable instead of smaller spools of cat5e and coax cable.
But the last time I looked, pretty much everyone agreed that coax cable provided the best signal for video. So you might save a bit of money, but at the cost of a poorer quality signal.
There are devices known as baluns that will take video from a normal coax and send it along Cat5e or Cat6, then reverse at the other end to put the video back onto coax. For relatively short distances, they do a fine job at it, and won’t degrade the image to much worse than RF (eg: transmitting the video on Channel 3)
I would not try such a stunt with component video as the bandwith is higher, (a lot higher, if you’re doing hi-definition) and timing of the three signals arriving at the same time is important.
One advantage to using baluns and CAT5 rather than regular old coax is that the CAT5 has extra conductors in it so you can do multiple feeds on a single cable, and some baluns even provide an easy way to use the extra conductors to provide low voltage DC via the cable as well, so you don’t have to have a power outlet and transformer near your video source (e.g. for security cameras).
Baluns as a general concept don’t necessarily lead to an inferior signal. The term “balun” comes from the practice in professional audio of using such devices to convert to/from a “balanced audio” signal ( “balun” : balance/unbalance :: “modem” : modulate/demodulate ) when you want to run audio a long distance without degrading the signal or introducing noise. However, that’s audio. I don’t think there’s any such thing as “balanced video”, so your signal is probably not really protected in any special way. How it does over unshielded twisted pair relative to coax is anyone’s guess. The baluns still could conceivably do tricks like amplifying/attenuating the signal to resist noise in transit, but that seems fairly unlikely for consumer-level stuff, especially since it would mean the baluns themselves would need to be powered.
Thanks for the input. I think I’ll stick to regular coax cables with the standard RCA connectors. The reason this seemed attractive was that I could get by with pulling fewer and thinner cables thru the walls, but I don’t think it’s worth the benefit if the HD signal will degrade.
Here is a professional product designed to do the same job. There will be some circuitry in those things designed to maintain the proper impedence and such, which doesn’t look to be the case just glancing at what you linked to. Our supplier tells us these work really well, but we tried VGA/Cat5 baluns from the same company and the projector at the other end of the 200+ foot run couldn’t quite find sync. We ended up getting a 250’ vga cable for that job. If it’s at all possible, I’d use coax for the job. RG-59 is pretty easy to pull and should be plenty adequate for a short run like that.