[TowerTalk] Antenna Question

[Robert Kirkland]

When I put up my low frequency dipole from the tower to a tree it will be 
center fed with 450 Ohm ( home made ) open wire line. Eznec says I will have 
a 7:1 SWR. A 1:1 Balun would convert that to 50 Ohms with the 7:1 SWR. My 
question is what happens if I use a heavy duty 4:1 Balun. Do I divide the 
7:1 ratio by 4, or what?. And a why, would be helpful. Also throw in any 
math. Thanks.
Bob, w5pvr