dykesc wrote:
I'm going to 450 ohm window line to my OCF Dipole. Obviously, as
confirmed by EZNEC, without some kind of choking action at the
feedpoint, my feedline will be radiating. What kind of 1:1 choke could
I use on the 450 ohm line at the antenna feedpoint? I could build a
1:1 choke with the right toroid but not sure if I can maintain the 450
ohm line Z0 through the choke.

It is very difficult to choke 450 ohm window line.
I would suggest a husky 1:1 current-choke-balun at
your window-line/coax junction. The Carolina Windom
advertises feedline radiation as a benefit/feature.

With an OCF, fighting feedline radiation is usually a
losing battle.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com