Newsgroups: rec.audio.tech
Subject: Re: Component video really need 75 ohm cable?
References: 
"Ethan Winer"  writes:

> Hi Folks,
> 
> I just upgraded to a new "progressive" DVD player and of course the salesman
> tried to sell me a $50 component video cable to connect it. So for now I'm
> using a regular three-wire RCA cable meant for composite video and
> Left/Right audio, and it works, but I'm wondering if I really would benefit
> from better cables.

Practically all analogue consumer video interfaces are designed top use  
75 ohm coaxial cable. This is the right cable to use in all those 
applications and gives guaranteed performance. If you use something 
else, then the results you cet can vary from good performance to poor 
performance depending the cable used, cable length and sometimes 
even on equipment used. Usually with showr wires od few meters 
the "normal RCA cables" do not cuase problems on normal TV signals. 
But when cables get longer or you have higher resolution signal 
(progressive video from DVD, HDTV signal, computer VGA signal), 
problems are more easily seen. 

The cable you used most propably is designed to have two 
different types of cables it. 
RCA terminated video cable is generally 75ohms. 
The audio wires are general purpose shielded audio cable, 
that can have considerably different impedance than 75 ohms 
and has generally considerable higher attenuation than 
video coax cables (bnecause of different insulation material used). 
I have also seen video + audio cabls where all three wires 
are all the same general purpose audio cable type..

Depending on the distance from the video source to display 
device distance, you might or might not benefit from the better 
cables. If your cables have length of one meter or so, then 
changing cables most propably do not have any noticable effect. 
If your cables are 10 meters long, you most propably can 
see some difference. 

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/