Question about un-un's/baluns

Been reading for months about these. Now we have all heard of the SRC multi band antennas and I now believe they use the 9:1 UN-UN for them, what I want to know is what would be the difference between a 9:1 UNUN on one of there base station antennas and there mobile ones, is there any, Ive built a 9:1 lately but not had a chance to try it yet. The other thing that's still confusing me is all the different types out there, when they say its a 9:1 or a 4:1 what exactly is the difference in the way they make them, for eg a 4:1 has more than 4 turns on a ferrite ring lol. I'm still trying to work all these things out, also you get some wound with 2 wires and some wound with 3.

So maybe someone might be able to help me out here. I'm really wanting to try one on a 11 metre mobile antenna or even a modified one.

I will be trying all the different designs and sizes until I get it right but would love to get one to work.