All the plans I've seen for a g5rv require either rg8 or rg58 etc. cable. I've
seen people say you can go straight to the ladder line and some say not. Best
advice is to try it but whomever made that thing for you ought to be able to
tell you what kind of cable it called for. I've also found that usually a 50ft
or 100ft cable works best if you're using the full sized g5rv.
Tom
Tom Brennan KD5VIJ, CCC-A/SLP
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html