The design I have seen is a 3 wired type each side, where the 3 wires join
together at each end.
....[snip]....

Someone mentioned a bowtie, but with just a bit of not-looking-carefully-
enuf, it might be a three-wire folded dipole?

IIRC, put a one-wire (each side) dipole high enuf and its impedance is
about 72 ohms.

Use two wires and get 2x2x72 = 288 ohms (which everyone says matches
300-ohm line).

Use three wires and get 3x3x72 = about 650 ohms, which might be well fed
with open-wire feeders?

I also recall folded dipoles are somewhat more broad-band than single-wire
dipoles. (Because they are effectively "thicker"?)

Brings up another question: can folded-dipoles be good multi-band antennas?

--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)