i've found adapters to convert s-video to rca, and it looks pretty simple. just a cable with a s-video on one end and a rca on the other. but ive been looking around for a way to make one my self and came up with nothing. anyone know of a how to anywhere that can help me?

 

http://www.tkk.fi/Misc/Electronics/circuits/svideo2cvideo.html

nevermind

 

That will work and you should not have much additional degradation. Not that you could tell on a crap NTSC video in.

 

I've used that config before in an emergency. It's OK, but there are some nasty chroma effects on certain content.
Proper combination of Luma and Chroma signals into a composite signal requires a much more complicated Active circuit.