Thanks for those tips Hpro. I didn't mean I was going to buy coax for this application - just that the coax that I use now for my internet is split off from behind the entertainment center and runs through the walls to the computer and it is a 50ft cable with a little left over. That is why I will need a 40-50 ft rca cable instead of the 30ft I mentioned in the beginning. Sorry for the confusion...
My main question was what diameter of lead wire I should be looking for at Radio Shack - so by your picture I will see if they have some in the 2mm range.
If you really want to understand - try changing it.
NZXT Lexa_Asus P5E_E6750 2.66Ghz_GSkill 2GB PC6400_Mushkin 2GB PC6400_WD SE16 250GB_Pioneer 16x slot dvd_Pioneer 16x dvdrw
ATI x1600pro 512mb