Electric fence wire is aluminum, comes on 1/4 mile, 1/2 mile and mile rolls,
works great for ground radials but is to soft for antennas, IMHO.

Best wire I have found for antennas is what the local phone co-op calls
"field wire". They lay it down during the winter when they can not trench in
a new copper line. In the spring they roll it up and toss it away after they
trench in the new line. This stuff is 7 strands of steel, covered with a UV
protective outer plastic shell. Stuff will last for years, stretch and
return to shape, and if you bundle enough together you can pull a car out of
the ditch in a pinch. Have had it up for years as a 40 and 80 meter dipole.
Hard as the dickens to work with, almost impossible to solder, but, it makes
a dipole even northeast Montana winters can not break, something to be said
for that.

Just my two cents worth.

Sam