On Mon, 27 Jul 2015 09:34:08 -0700, "Wayne"
wrote:

Let's say I have a perfectly balanced dipole with a feedpoint impedance of
72+j0 at my frequency of interest.
I connect a perfect 72 ohm coax (an unbalanced connection) to the feedpoint,
and drive the antenna system with an unbalanced 72 ohm source.

Since the power sent to the antenna is not reflected, do I need a balun?

If you're doing this test in free space, then you won't need a balun.
However, reality has a way creating problems with perfectly balanced
dipoles. If your antenna construction, mounting, or grounding
arrangement does anything to ruin the perfect balance of the dipole
and produce common mode currents in the coax, the coax will radiate.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558