Best antenna wire is copper-clad steel, number 12.
A bear to work with because it is springy.
When fastening to trees (they get angry, remember?), use some kind of
spring, bungee cord, or other shock mount beyond the insulator (i.e., the
antenna wire is solid, make the mounting method take the wind sway).
Or, use the rope, pully, and counter weight shown in the ARRL antenna
books and elsewhere.
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