"VK3XL" wrote in message
...

Hello all, I am planning to erect an 80 meter full wave loop antenna in
the back yard. The articals I have read so far all seem to feed the
antenna at a corner with either 450 ohm open wire line or feed direct
with 50 ohm coax. Due to the layout of my yard it would be preferable
that I feed the antenna at the mid point of one side of the antenna
with 450 ohm open wire line to a tuner (4:1 balun included in the line
and coax to the tuner). Is there any disadvantage in feeding the loop
mid way along one leg rather than at a corner?

For a loop, 20 m per side, 10 m above an average ground, the input
impedance is about 100 ohms (at 3.825 MHz). Feeding at the
corner, or the center, makes no difference to the input impedance.
The radiation pattern will rotate by 45 degrees. Very good high
angle radiation. At a 30 degree elevation angle the pattern is
like a dipole, with nulls about 4 dB deep, and max gain - 4 dbi.

73,

Frank
(VE6CB)