You might find it instructive to take a look at
http://eznec.com/Amateur/Articles/Baluns.pdf.

Roy Lewallen, W7EL

RB wrote:
I've recently put up a 140' dipole fed with ladderline. My tuner is
separate from my rig, and is an unbalanced unit. So, I use a balun on the
tuner output to hook the ladderline to.

I've been told that I should have a voltage balun in this application. I
was surprised to hear this, as I expected to hear use a current balun.

Is the voltage balun the right one for this application?