Composite over cat5e

[independentpete]

Could use your guys' advice on a slightly different setup... I'm currently sending video from PC to TV, over about 40 feet of Cat-5e, terminated with Leviton S-Video Quickport Connectors. Quality is OK, but I'm sure can be improved. I'm guessing that these connectors don't do anything to improve quality. Can you guys recommedn some [not-too-expensive] devices for sending S-Video? Assuming baluns... Right? Are some better than others?

P.S. Don't need to send audio, only video. S-Video preferred since that's what the PC is already outputting.

 

[rocco]

You could use four baluns, two at each end. The cost is therefore twice that of composite video. Two separate 75 ohm coax would be the best/cheapest solution.

S-Video is simply composite video with the chroma signal separated out from the luminance signal and carried on a second 75 ohm coax. The intention is to allow the bandwidth on the luminance to exceed the crummy 3.5 MHz ceiling that the chroma signal imposes. So it is just an "enabling" technology. The actual video bandwidth may or may not be better than composite. The luminance (black and white) signal can be improved a lot, but the color bandwidth is still limited.

Component or RGB solves the color bandwidth problem, but needs three 75 ohm coaxes.

 

[independentpete]

Unfortunately, running more coax between these two locations is not really an option. I'm pretty much limited to Cat5. If I have two baluns at each end, what kind of connections do they have? Two composite? How do I get that in to and out of my video source? Or, am I misunderstanding?

What about these MuxLab VideoEase S-Video Baluns? - http://www.muxlab.com/products/ve_svd_s-v_balun.html They seem popular. Can I expect to get better quality than from the Leviton S-Video Quickport Connectors that I'm using now? Thanks!

 

[electron]

I run video over cat5 as well (175ft) and had to purchase a set of baluns because of the distance. It made a huge improvement, but not sure if you would see the same major improvement over a 40ft run. You could always send them back and tell them they don't work in your situation. I use 1 pair of 4 pairs for video.

 

[rocco]

Pete, that MuxLab product is exactly what I mean, though those units may not be the best. It contains two baluns at each end, puts chrominance over one twisted pair and luminance over another. Its bandwidth tops out at 6MHz, which is really only enough for about 320 pixels across. This unit, http://www.muxlab.com/products/ve_svd_2w_av_balun.html is good to 8MHz. For comparison, you might notice that their VGA baluns are rated at 60MHz.

So the bottom line: Depending on the bandwidth of your source, these baluns could actually degrade your signal if your source contains a lot of bandwidth. What is the source and resolution of the video you wish to transport?

 

[independentpete]

For some reason, I don't get e-mail notifications of replies. That's why I haven't replied in so long.

rocco: The source is a PC, which I [sometimes] use for viewing movies. Resolution is 1024x768, but can be adjusted. I'm using the S-Video out on the PC's graphics card.

Not sure that I understand how I would use the VideoEase Dual Audio-Video Balun that you suggested. Is there some sort of adapter that converts the multiple composite connectors to an S-Video connection?

Would I be better off using the VGA or DVI out on the graphics card? My TV doesn't have a VGA in, so what can I use? It has DVI in, but manufacturer (Sony) says not to connect a PC to this. What about component in? Keep in mind that my transfer medium is Cat5 and I have 4 (maybe 8) pairs available. What devices would I use at each end to connect to any of these other outputs/inputs? Don't make me go broke either, I have to save enough for one of those $226 geeks.com PCs.

 

[hult]

I know this has been discussed a thousand times.. ( all right almost a thousand ).

I haven't seen a completely whole answer yet.

[snip]

My wrinkle on "haven't seen a completely whole answer yet" is whether composite video using high quality baluns on the 'unused' brown pair (7,8) of Cat 5e *and* 100BASE-T conventionally on 1,2,3,6 can co-exist without significant degradation of either signal in the same Cat 5e cable.

I'm looking for advice based on actual experience as to actual _performance_, not general advisability of mixing uses within a Cat5e cable.

TIA ! ... Marc