RGB to SCART signal path questions

[Mayhem]

I am currently constructing my very first supergun and would like some more information on the RGB to Euro SCART signal path.

As I recall resistors are needed on the RGB lines to bring the voltage down from arcade to TV levels, but which resistor value do I need?

I also have vague recollections of putting capacitors along the RGB lines, while others have discarded it as bogus... What is the current verdict on this?

Should I make any modifications to the sync line?

Is +5 VDC through a 100 Ohm resistor into the RGB blanking pin correct?

Anyone know if the RGB voltage levels for the Japanese SCART pinout as used on XRGB-2+ units are the same as Euro SCART?

[Mayhem]

Bump... where are all the supergun builders?

[thegreathopper]

I am currently constructing my very first supergun and would like some more information on the RGB to Euro SCART signal path.

As I recall resistors are needed on the RGB lines to bring the voltage down from arcade to TV levels, but which resistor value do I need?

I also have vague recollections of putting capacitors along the RGB lines, while others have discarded it as bogus... What is the current verdict on this?

Should I make any modifications to the sync line?

Is +5 VDC through a 100 Ohm resistor into the RGB blanking pin correct?

Anyone know if the RGB voltage levels for the Japanese SCART pinout as used on XRGB-2+ units are the same as Euro SCART?

No mod needed to the sync line,+5 Vdc and a 100 Ohm resistor on the blanking is what I always use.
As for the resistors on the RGB lines I have always used small 10K pots and adjusted the brightness that way.

I have never had a need for Capacitors on a supergun or MVS console, only ever needed caps on Nintendo RGB scart leads.

[cantido]

To get the right voltage going into the scart socket you need to work out what is coming off the board and then add enough resistance to drop the potential down to whatever your scart socket accepts, which I think is .7v max.

Saying that I run the lines off my neogeo straight into my tv and have no issues.

[tyranid]

Adding caps are just to remove any DC bias which as pointed out was an issue on SNES consoles. I don't think it is an issue on JAMMA but I could be wrong

[penrhos]

Same here - 100 Ohm on blanking and 10K linear pots on R, G & B to adjust the colour bias.

The XRGB-2 Scart plugs are wired for Japanese scart leads and the pinouts are different as for the need for resistors on the leads you'd need to ask Meg as my XRGB-2 is still sat in the garage and unused.

[cantido]

I don't think it is an issue on JAMMA but I could be wrong

If you're building amps and stuff like that it's always been a rule of thumb to put DC blocking caps in... They don't hurt if you don't need them, they cost very little and will save headaches if it turns out you do need them.

[thchardcore]

Please explain the above. Keep in mind, I am in the US and using a special find of a monitor, a Toshiba "timm" that accepts 15 khz over the vga plug (as well as 31 khz obviously). I bought scart leads for saturn, super famicom, megadrive and playstation1/2. I will just S-video for N64 and VGA for DC for now (I hope to hack the vga box to output 15 khz via switch as well). I need to know if I should remove the resistors that are in there already, as I dont think I need them, I know for sure I won't need blanking, 5v etc). My question is, will I need to do anything else besides change the values, if needed?