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Talk:RCA toCAT5conversion

I wonder what happens if I connect this to my router... <no connection>

I'd be more interested in trying to hook it to a hub Suppafly 14:35, 3 February 2006 (CST)

Neat Project

. . .but RCA cables are actually pretty cheap if 1) their label doesn't contain the word "monster" 2) you don't buy them from best buy/circuit city/etc.

check out monoprice (http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10218&cs_id=1021803&p_id=2009&seq=1&format=2&style=)

 cheap cables

Kevin Rose did a show about making your own cables, I believe it was systm episode 3. You can find it at (http://www.revison3.com/systm). They also explain how to correctly organize your cables

Does this work without looking like crap?

What is a Balun? A balun is an impedance transformer that allows you to send a signal that requires a certain impedance value (such as 75 ohm for video) over a cable that has a different impedance (such as CAT5 that has 100 ohm impedance). You need one at each end, one to transform the original impedance to the impedance of the cable and the other to transform it back to the original impedance.

A VIDEO BALUN is the key component that allows you to transmit VGA, RGB, YPbPr. YCbCr, S-Video and Composite video or audio over Cat5. It's important to use video baluns when sending video over Cat5 since the impedance specifications of Cat5, Cat5e and Cat6 are 100 ohms. Video requires 75 ohm impedance and you'll introduce artifacts to your video without a balun. Basically, if there's an impedance mismatch the signal will be reflected from the receiver back to the transmitter causing delays in the signal transmission; the delays have a ghosting effect on the picture. It's like your TV on drugs.

Actual experience

I just finished building this project, and it works fine for me. Yes, there is an impedance mismatch so you get some noise on the audio and video, but it is barely noticeable when running 25-30 feet (the length of my cables). The fact is unless you get the highest brand cables, there are impedance mismatches between RCA connectors and cables, so it is nothing to worry that much about.

Overall, great project (though building the boxes can be a little pricey) and not too difficult.


But why?

Even ignoring the obvious impedance matching issues, why do it? For the roughly $10 * 2 price tag you could simply make the right length video and audio cables yourself. The only advantage I see is that it runs over cat5. But in my opinion the vastly superior quality of properly made cables far outweighs any benefits of the cat5. Now if you were feeding video and audio through an existing cat 5 network for video conferencing or some such thing, I might see a purpose. But even there, it's not a permanant solution, it's a quick hack for an odd situation. If someone actually needs to do this, there are several commercial products out there built specifically for this. But what do I know, I'm just an electrical and computer engineer with years of experience in the video production industry?

Not Feeling It....

This doesn't work well at all. To do it properly, (as mentioned earlier) you need a balun to convert the unbalanced output to a balanced signal to travel over the twisted pair wiring, and another balun to convert it back. The method used will be OK for 10-30 feet at the most, but it would be cheaper to do it the right way to begin with.

Shielded Wiring

First off, this is a neat thing. I like people doing their own "hacks" to make their life easier, and the more power to you.

However, in addition to the changes of impedance in the wiring (don't know so much about these balun boxes, or whatever people were calling them), you have to consider the twisted pair nature of the Cat5 cable. "Good" or "well made" RCA cable has the signal wire running down the middle, and the ground wire as a shield over the entire length. This helps keep the signal clean! When you convert it to Cat 5, you just twine the two wires around, and disregard the shielding inherent in the original design, which can also introduce artifacts, as the three signal wires pick up signal/noise from each other.

Just a thought :)

Not Worth It

You can get really cheap stereo RCA cable which is meant to be used with speakers only. But, it will work for video too. Or you can go with a better cable for your video (yellow) connection. But the speaker wire works great for the red and white connectors, b/c thats what its made for. It has some problems with video over 25 feet or so due to inadequate insulation.