Component and composite?????

Francis 18

Standard Member
Hello :hiya:

Can someone please explain to me the difference between component and composite signals.

Also I had an RGB cable installed behind my wall about 6m long and i bought convertors to convert to scart. 1 end is plugged into my sky box and the other into my tv but there is no signal comming through the cable.

Any feedback would be much appreciated :lease:
 

AV Online

Well-known Member
AVForums Sponsor
Hi Francis,

When you say you have an RGB cable installed I assume you mean a component cable - 3 phono/RCA plugs marked red green and blue? You will most likely have to set the Sky box to output RGB if this has not already been done and make sure that the converter is connected into the TV our scart on the box (under video settings change Video Output to RGB). If you still have no picture a little more information on the converter you are using would be useful :)
 

Francis 18

Standard Member
Yes thats exactly the cable I am using. The convertor I am using has 4 phono inputs, red, green, blue, yellow. It also has a swith which is marked in/out.
 

Mr Incredible

Distinguished Member
Yes thats exactly the cable I am using. The convertor I am using has 4 phono inputs, red, green, blue, yellow. It also has a swith which is marked in/out.
This is an adapter not a converter.

A Scart connection feeds "RGB" signal AND a sync signal on the composite video pin on the scart socket. All four are needed to correctly decode the signal.

A component signal carries the sync signal supplanted onto the "green" signal and is totally different to the RGB on Scart set up.

Your lead/adapter will not get you a picture from your Scart output to a component input. You need a box of electronics to convert between the two.

Keene Retail Ltd
 

Joe Fernand

Distinguished Member
AVForums Sponsor
As Mr Incredible says your cable will be a three core 75 ohm video cable – you can stick all manner of video over the cable as long as the devices on both ends can support the required signal type plus you can get the single down three or less cores of a cable.

With your SCART equipped Sources set to RGB your outputting RGB+ Composite Sync and as Mr Incredible says you will require some form of converter to get that signal down your three core cable.

Converting RGB to Component (YPbPr) is ideal IF the device on the other end of the cable supports Component (YPbPr) video – assuming the TV does have a 3RCA Component input you also need to ensure it supports the signal format your outputting (480i60 or 576i50) some older displays were fine with 60Hz from a R1 DVD but not so good with 50Hz (from a SKY box for example).

For Converters and Tech info AVForums member and Sponsor Dr John (Simm) is always the best person to consult - J.S. Technology

Prob best if you can list the kit you are trying to hook together.

Joe
 

Francis 18

Standard Member
All I am looking to do is get a picture out of the sky box via the scart port as there is no RGB ports and transfer the signal down a 3 core phono cable (RGB) and connect to a brand new LG tv. What do you think would be the best way to do it?
 

Mr Incredible

Distinguished Member
All I am looking to do is get a picture out of the sky box via the scart port as there is no RGB ports and transfer the signal down a 3 core phono cable (RGB) and connect to a brand new LG tv. What do you think would be the best way to do it?
You need a converter to get the R+G+B+Sync signals which are sent over 4 cables from the sky box's Scart output (referred to as RGBs) and convert to R+G+s+B (referred to as RGsB) over 3 cables.

Just bear in mind that this set up will not send sound to your TV, only picture. I presume you have external amplifier to deal with the Sky audio'left right or optical output?

One assumes your TV is equipped to accept component (RGsB or aka (YPbPr) input?
 

Joe Fernand

Distinguished Member
AVForums Sponsor
I know all of the three and four letter acronyms are a pain but have a read of what’s been posted already!!!

You can set the SCART Output on the SKY box to RGB – though that only helps if the SCART Input on your Display is also RGB enabled.

RGB as used by SKY (and most other Consumer devices) is a FOUR wire signal – Red, Green, Blue + Composite sync; you can’t transfer it over a three core cable.

There are versions of RGB used in the broadcast world that will go over a three core cable but SKY don’t use that form of RGB – again see Dr John’s notes.

If your TV lacks a 3RCA ‘Component’ video Input your stuffed unless you have a four core cable.

The best you can do is set SKY to RGB and use a JS Tech RGB to S-Video converter to get S-Video to the TV over two cores of your three core cable – again only relevant if the TV has an S0-Video Input or is S-Video compatible via SCART.

RGB to S-Video Converter: J.S. Technology

If the TV lacks an S-Video input the best you’re going to get is Composite over a single core of your cable.

I would have thought your ‘New’ TV would have a Component Input and use the JS Tech RGB to Component converter - RGB to Component (YUV) Video Converter: J.S. Technology

We can only make it so simple – you have to do some of the work here :thumbsup:

Joe
 

Francis 18

Standard Member
No external amp, just a stand alone sky box. Do you think it would be best to fit a standard scart (sky box) to scart (TV) lead and do it that way?
 

Mr Incredible

Distinguished Member
We can only make it so simple – you have to do some of the work here :thumbsup:

Joe
And some are better than others! Thanks Joe.

Thes Sky box will most likely have S-Video output, so providing the TV accepts S-Video, I'd use that instead of buying a RGB to S-Video converter.
 

Mr Incredible

Distinguished Member
No external amp, just a stand alone sky box. Do you think it would be best to fit a standard scart (sky box) to scart (TV) lead and do it that way?
Right, in which case use the adapter you have to squirt the video signal (yellow lead) and the audio L-R (red and white) down the three cables you have, then either conenct the yellow/red/white direct to your TV if it accepts composite video this way, or have another adapter that will allow the three leads (composite + L-R audio) to connect using a Scart (i.e. the reverse of what you have). Note, composite picture is the lowest of the low and will look grainy compared to what you could get if the whole signal chain was RGB. But without changing the cabling you have now, you're limited if you do not have external sound reproduction. HTH
 

Joe Fernand

Distinguished Member
AVForums Sponsor
Hello both

Mr Incredible – right enough; forgot about the SKY+ box having S-Video out; should have remembered as I had to use one at the weekend on a temporary lash up for a customer who’s Projector went on the blink.

Francis 18 – if you can replace the installed cable with a fully wired SCART cable then yes that would be your best option and set the SKY+ and TV to RGB in the User settings.

Joe
 

Mr Incredible

Distinguished Member
Mmm, dunno if the older Sky boxes had S-Video out. Check on the back side.

IF the cable behind your wall can be changed for a fully wired scart cable, then that would solve all your problems: best picture; sound; no converters needed.
 

Francis 18

Standard Member
I will have a look at the box and check that out. I think the best solution here is to try and feed a scart lead across to the tv.
I am fairly new to the AV enviroment so to speak so I am learning as i go. Thanks for your help :thumbsup:
 

Joe Fernand

Distinguished Member
AVForums Sponsor
From memory S-Video was on SKY+ not SKY.

As above a fully wired SCART cable and your kit set to RGB will solve all your problems and give you a decent picture quality.

Joe
 
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