I’m done some searching, but I haven’t found a conclusive guide to solve my problem. So I thought I would ask the teeming masses. My dad just bought a new house and has one of those TV above the fireplace setups. This means that all of his components are in the corner of the room away from the TV. There is conduit run between the two positions and the cable runs are about 30 feet. I need to run 2 component video connections (1 for HD cable box, 1 for DVD player), 1 composite video (VCR), and 1 coax connection (so mom can use the cable box without the stereo for sound). So if I run individual cables I need 3 for each component (6 total) plus 1 for the composite and 1 for the coax connection which is 8 total. Since this is a large number of cables to fish through the conduit with connectors, we are thinking about making our own cables. I’ve looked around and seen recommendations for using quad-shielded RG6 and either crimping or soldering RCA connectors to the ends. Can you guys provide me with some suggestions for what I need to buy and if this should work for my situation? Or is there a better way to go about this?
You could use good twisted-pair cable, like good-quality Cat 5 or 5e ethernet cable. You’ll use one pair per RCA cable you’re running. The pairs on standard Cat 5 are:
Be sure to use the same pairing scheme all around–for example, if you use the solid color of the pair on the (+) (pin) and use the striped color for the (-) (ground), then do so for all cables to maintain correct polarity. You’ll need two such cables for all 6 interconnections you’re running. At each end, break out the pairs and run them directly into solder-tab RCA plugs, maintaining the twist right up to the connections. Cat 5 cable has a rated bandwidth of approximately 100 MHz, which is more than sufficient for a video signal.
Extra points to Q.E.D. if he can put those colors in the right order.
Just for the record, I’ve used phone company standard 4- and 6- pair wire (Officially Cat. 3) for stereo hookups, and I never noticed any difference in performance. (Granted, I never tried for video.) I only mention this because Cat 5 can be expensive, while Cat 3 is less so, and sometimes you can maybe get a cool phone guy to donate a length to your cause. If QED thinks Cat 3 will ruin your video experience (I admittedly don’t know the bandwidth specs) then never mind my post, and go with his suggestion. If you go with 6 pair cable, the additional colors should be
SLATE (gray) + WHT/SLT
and
RED + RED/BLUE
This offers the advantage of 2 more pairs in one wire.
Wild idea. I never would have thought of using Cat5 like this for video. Looks like the OP will be able to do the job with two runs of Cat5 and one normal RG6 coax for the cable TV line.
Certainly a lot easier to fish than eight RG6 lines!
The RGB lines for the component video need to handle a high bandwidth because we will be passing HD TV video through the cables. Should the CAT5 be able to handle this the HD signal? Thank you for the responses so far. Any more ideas are appreciated.
From what I can tell, none of the HDTV formats (1080p, 1080i or 720p) need more than about 20 MHz, maximum. I seem to recall that for minimum loss, your transmission cable should be rated for at least 5 times the intended signal bandwidth–I’ll see if I can look that up and verify it. Cat 5 should be just fine for this purpose.
Cat 5 doesn’t have to be all that expensive. I had to look up prices on it the other day, and it was running about 35 Euros for 100 meters of Cat 5 cable with the pairs separately shielded. Good stuff.
100 Meters of Cat 6 costs about 70 Euros. Also not bad.
Video signals are normally transmitted on 75 ohm coax cable (e.g. RG-6 and RG-59). Coax cable also offers some EMI shielding. By contrast, Ethernet cable (e.g. Cat 5) is unshielded twisted pair (UTP) with a nominal impedance of 100 ohms. You can get away with wiring UTP directly to BNC connectors for short runs (less than 1 meter) or “low-quality” applications such as CCTV. Otherwise more work is involved.
(I understand you’re running it in conduit, and if it’s metal it will offer some shielding. But you’re still stuck with the impedance mismatch problem.)
I don’t have time to read the following articles, but it would appear the authors are recommending the use transformer baluns when transmitting video signals over UTP. They may also be offering other tips. If I were you I’d read both articles in their entirety, and then decide if UTP is the way to go.
<cable snob>I would use at least 9913 (RG-*/U with a 10 AWG center conductor) for video, and only if 1.5in hardline wasn’t available-or better yet, fiber optic</cable snob>
Thanks guys. Crafter_Man I will check out that article on the CAT5 and video. There are 2 - 1" flex conduits (corrugated) that we can use to run the video connections.
