[Antennas] Loop vs Dipole

[Ron & Madhavi]

Here's a tough one....or is it?!

I live in a townhouse in Kingston - the backyard is no more than 32' long
and 10' wide, with a concrete parapet wall at the back.

I have a 25' tall aluminum pole clamped to the wall and ran an inverted vee
on 20m (25' at the apex). Results were fair and with my 850S, I worked into
Asia and more consistently into Europe.

Wanting to improve on it, I replaced the vee with a full wave loop and
expected it to outperform the inverted vee. The loop has perfect resonance
(a nice 1.1 SWR). The matching is done with a  1/4 75 ohm transformer.
HOWEVER, even though I have tried to move the feed to a corner, 1/4 from a
corner, center, apex etc., nothing seems to make it outperform the inverted
vee. I know that this does not confirm theory -- as the loop is larger, has
a lower take off angle (at least so they say!) and better SWR etc.
Adddmitedly, the base of the delta is a FEW feet lower off the ground than
the ends of the vee, but I expected the claimed superiority of a full wave
loop to offset that.

Used many 40/80m lops in the past, but never compared them to dipoles and
vees at the same height! The results however were quite pleasing. First time
I am running comparisons on  loops and dipoles on  20m . Is the superiority
of the loop greatly exaggerated or am I missing something here?  I have
written articles encouraging people to use lops instead of dipoles and now
wonder if I lead them astray!!!!

Again...perfect resonance (checked witha  RF1 at the feed point, end of a
half wave section of coax and after matching with the 1/4 transformer too! I
can't see I have made any mistakes here! If its the height......how come the
inverted vee works MUCH better?

Any thoughts. comments, advise?

73,
Ron, 6Y5/4S7RO