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#202198 - 03/02/2004 11:30 Quick Video Cable question
darwin
enthusiast

Registered: 10/01/2002
Posts: 205
Are Component Video Cables, like the ones used to connect progressive scan dvd players, the same as RCA cables, just 3 of them instead of the 1 yellow cable?

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#202199 - 03/02/2004 11:36 Re: Quick Video Cable question [Re: darwin]
webroach
old hand

Registered: 23/07/2003
Posts: 869
Loc: Colorado
Yup!
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Dave

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#202200 - 03/02/2004 11:41 Re: Quick Video Cable question [Re: darwin]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Ideally you should be using 3x video cables as the audio cables won't have the correct impedance. It'll work over short runs using the standard audio + video RCA cables though.

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#202201 - 03/02/2004 11:43 Re: Quick Video Cable question [Re: darwin]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31596
Loc: Seattle, WA
Yeah, I often use the three-wire stereo/video assemblies to connect component. Red for Pr, Yellow for Y, white for Pb. Works fine.
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Tony Fabris

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#202202 - 03/02/2004 11:54 Re: Quick Video Cable question [Re: tman]
darwin
enthusiast

Registered: 10/01/2002
Posts: 205
tman: So there is an impedance I have to worry about? The run will be less than 10 feet.

The reason I'm asking is because I just bought a new house, that is in process of being built. Since they are still building it, they are letting me put all the add ins I want. So far I have them putting 10 Cat 5 runs throughout the house, extra cable tv outlets, extra phone outlets, wiring for 5.1 speakers, etc.

Now, I decided to spend a little on a mini theatre room with a flat panel TV hung in the center of the wall. Obviously, I don't want any wiring to come from anywhere so I'm having them wire outputs for the Component DVD input, Component HDTV input, SVideo and Power for the TV behind the walls. They said this wouldn't be a problem, but I want to make sure the wiring will be okay.

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#202203 - 03/02/2004 11:57 Re: Quick Video Cable question [Re: darwin]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31596
Loc: Seattle, WA
If the wiring is only 10 feet, you have nothing to worry about.
_________________________
Tony Fabris

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#202204 - 03/02/2004 12:00 Re: Quick Video Cable question [Re: darwin]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Video cable should be 75 ohm. Audio cable is less than that and if you use it for video then it's possible to get signal reflections which give you ghosting. If you can then buy just normal video cable and run three lots of that just to be safe. If you want to know the details then go here.

One thing tho. You can never have enough wiring in the walls! It's much easier to run the cables now than later. Get them to put a pullstring in as well if you think you'll ever need to add anything.

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#202205 - 03/02/2004 12:06 Re: Quick Video Cable question [Re: darwin]
Cybjorg
addict

Registered: 23/12/2002
Posts: 652
Loc: Winston Salem, NC
The true answer is yes and no. It is "yes" in the fact that both sets of cables carry a video signal from point A to point B. It is a resounding "no" when you consider the quality of that signal varies from one to the other.

While RCA cables are the norm, they were originally designed for audio signals rather than for video, and Characteristic Impedance (CI - the sum of the capacitive and inductive reactance with the signal) of an RCA plug is generally about 25 Ohms.

Component cables (including the RGB varients) carry a much improved 75 Ohm CI signal. One must be careful, however, as the cables with RCA plugs used on them are not. Cables with BNC plugs used on them are 75 ohm CI.

BNCs are a connector designed for video use (75 ohm CI). It is a cheap and HIGHLY reliable connector. BNCs come in crimp and solder varieties and are designed for specific cable dimensions (you match the cable to the plug type). The difference between one crimp BNC and another isn’t huge, especially in comparison with RCAs! They all work pretty well and other issues might be much more important to you like availability if coloured hoods (don’t underestimate the usefulness of coloured hoods on things like RGBHV cables). There are quite a few good varieties of BNCs. You can take your pick really. I would recommend Canare crimps. They are reliable, which is probably why most of major broadcasters around the world use them, although I am sure there are many other great varieties.

This may be more information than you wanted and most people could care less about a little bit of signal loss, but you did ask...


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#202206 - 03/02/2004 12:08 Re: Quick Video Cable question [Re: tman]
Cybjorg
addict

Registered: 23/12/2002
Posts: 652
Loc: Winston Salem, NC
Get them to put a pullstring in as well if you think you'll ever need to add anything.


Or conduit, if possible.

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#202207 - 03/02/2004 12:11 Re: Quick Video Cable question [Re: Cybjorg]
peter
carpal tunnel

Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
Component cables (including the RGB varients) carry a much improved 75 Ohm CI signal. One must be careful, however, as the cables with RCA plugs used on them are not. Cables with BNC plugs used on them are 75 ohm CI.
Except that you have to watch out, because BNC plugs and cables designed for 10Base-2 networking are 50 ohm...

Peter

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#202208 - 03/02/2004 12:15 Re: Quick Video Cable question [Re: peter]
Cybjorg
addict

Registered: 23/12/2002
Posts: 652
Loc: Winston Salem, NC
Ah, good call.

Anyone interested in pricing out component cables may want to check out Blue Jeans Cable.

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#202209 - 03/02/2004 13:20 Re: Quick Video Cable question [Re: Cybjorg]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Or conduit, if possible.

I'm gonna seccond this one. You don't just want cables in your walls, you want a way to add new cables to your walls easily. Conduit, with only 1 nylon string in it, is all you really want from your contractor.

Matthew

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#202210 - 03/02/2004 14:20 Re: Quick Video Cable question [Re: darwin]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12338
Loc: Sterling, VA
The reason I'm asking is because I just bought a new house, that is in process of being built
I hope your wiring guy is better than ours. We showed him exactly where to put everything. We walked through it with him. We gave him an illustrated layout of where everything would go. Now we have holes in the walls to the left and right of the TV, because that's where he thought the surround speakers would go. If you look at this picture (here's a close-up), there's a hole in the wall behind the picture that's hanging to the right of the TV. That's where he thought the surrounds would go. Maybe he thought we'd put the TV at the front door?

Oh yeah, and he neglected to run any phone lines to the two bedrooms on the second floor, where my two roommates would live. Oh yeah, and he incorrectly wired every one of the 12 or so cat5 lines we have going around the house.

So yeah, make sure they do it right
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Matt

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#202211 - 03/02/2004 16:52 Re: Quick Video Cable question [Re: matthew_k]
boxer
pooh-bah

Registered: 16/04/2002
Posts: 2011
Loc: Yorkshire UK
Or conduit, if possible.

I'll third it for when you want to put the DVI cable through next month, and HDMI in May, and whatever the industry has thought up to be essential by June - just be sure the nylon doesn't wear out!
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Politics and Ideology: Not my bag

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#202212 - 03/02/2004 19:15 Re: Quick Video Cable question [Re: Cybjorg]
Miltoid
journeyman

Registered: 17/10/2002
Posts: 57
Loc: Republic of Texas
Canare also makes true 75ohm crimp on RCAs; which is a great thing since almost no consumer video components have BNC connectors on them. The only catch is that really need to have Canare's proper crimp die for the size you're using in order make reliable connections.
Markertek is a good on-line source for Canare stuff.
_________________________
-Milton 100GB Mk2a / (DEAD)Tuner / Stalk Ford Ranger Republic of Texas

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#202213 - 04/02/2004 05:30 Re: Quick Video Cable question [Re: Miltoid]
Cybjorg
addict

Registered: 23/12/2002
Posts: 652
Loc: Winston Salem, NC
Good find. It's been a while since I've had to purchase cables.

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