Main > Monitor/Video Forum
How to use SCART for our hobby
Zebidee:
If RGB signal levels are the problem, then you could try running the RGB signals through a video amplifier, which you can find on a JPAC. Ultimarc also sell video amps separately. They are reasonably priced, only $21.
http://www.ultimarc.com/vidamp.html
If you try this, I'm very interested to know the result.
LeedsFan:
I've had a go at making my own RGB-Scart cable this morning, but it hasn't gone too well. I'm using the Ultimarc ArcadeVGA card and a VGA breakout cable also from Ultimarc. This cable had the wires labeled for easy reference. (Red, Green, Blue, HSync, VSync and Ground)
What I did was follow the instructions here and soldered the R G B wires to scart pins 15, 11 and 7 respectively. HSync and VSync I wired together and soldered to scart pin 20. I understand this is fine on ATI based cards as they put out -ve on each sync. I then soldered a short jump wire across from pin 20 to pin 16 to try and get the 2-3V ouput there.
Now the breakout cable I have has five different ground wires to just one pin. So all I did was put all these ground wires to pin 13. I didn't solder each R G B ground (or "return" as some people call it) to individual pins. Does this matter? I have no idea which are the separate R G B grounds anyway as these individual grounds aren't labelled. The cable just has five wires which are all put together and labeled "ground".
When I tried the cable I actually do get an image. But it's just a grey, shadowy image with no colour what-so-ever.
Zebidee:
It is extra effort, but it looks like you should try making your cable with 5v input + 100ohm resistor => 2v on pin 16
LeedsFan:
--- Quote from: Zebidee on April 25, 2010, 12:38:12 pm ---It is extra effort, but it looks like you should try making your cable with 5v input + 100ohm resistor => 2v on pin 16
--- End quote ---
OK I will try that. Just need to get some resistors tomorrow.
But I thought (with my extremely limited knowledge) that if I am getting an image then the jumper wire is doing it's job. I thought it was like a switch.. it's either on or off. And because I'm getting an image then the jumper wire is doing it's job. Or this not how it works at all? :dunno Does more/less voltage at pin 16 change matters?
Zebidee:
I've seen this before - Looks like your TV is not properly into RGB mode.
TV is likely looking for composite video and getting some picture signal (e.g. sync) from pin 20 but not proper RGB. You need to add the signal to pin 16 to get the TV to look for signals on pins 7,11,15 (B,G,R)