The fence wire idea is very good, but think of this.. If you live or travel in an area were there are large leases of land for cattle the top wire of the fence(barbed wire) on "dry" wood posts, cut to length and hooked to a random wire tuner can work like a charm. Think about it I'm camped next to a section of land fenced to live stock, with three insulators and some fencing pliers I can have a full wave 160M dipole. . Just remember to not make a break in the fence line that livestock can walk thru, by leaving an opening.