[Elecraft] feeding a half-wave dipole with ladder line

[Ed Cole]

I am redesigning my 40/80/160/630m antennas.

A year ago the tower I was supporting my 630m Invert-L was damaged by 
wind and taken down.  Replacement tower is shorter so not suitable end 
wire support for HF antenna.

I decided to repurpose my 80/40m dual dipole into a based-loaded 40-foot 
vertical using the 80 & 40m wires for top hat loading on 160/630m.  To 
do that I purpose to run 40-foot of ladder-line vertical and either load 
the bottom using a balun for 80/40m or short the ladder line for the 
loaded vertical.
http://www.kl7uw.com/630mTee.jpg

My question is what balun to use for 80/40m. ladder line is 200-300 ohm 
whereas the dipoles are near 50-ohm.  Should I use a 9:1 balun or would 
my original 1:1 balun work?  Tuners will be in the shack (KXAT at 100w; 
Drake MN-2000 at 1200w).  RG-13 coax to base of ladder-line.

I have a couple vac-relays to short the ladder-line and connect the 
loading coil for 160/630m.

Thanks, Ed - KL7UW