Base of loop will be about 6 feet above ground. RG-8 or 213 will be used for the feed wire. Ugly balun as well.
Best solution is with an antenna tuner for impedance matching. Cheap-try is quarter lambda 70 Ohm cable (to convert 100 Ohm to nearby 50 Ohm) AND common-mode isolator. I assume your loop is NOT parallel to the ground, since it makes no sense at 14 MHz to have your radiation straight upward. PA0FSB