You could use the 18 gauge insulated stranded CCS (Copper Clad Steel) wire that Davis RF and The Wireman sell. The PE jacket is a matte black color and not very visible from any distance away. It's pretty strong too, and not very expensive. I use it a lot for wire antennas.
I'm amazed your 22 gauge wire is holding up for elevated radials! Especially 135 feet long! I would expect such small wire to break pretty quick used in your application so I'm really surprised it's working for you. Regarding the resistance, I doubt it would make much of a difference. I'd go with larger wire more for strength than anything else. I use 18 gauge solid copper for my own on-ground radials (but I have some 40(ish) of them). -Bill > I use 3 raised radials ~ 135 feet long of #22 ga. solid wire. > used for dog perimeter control and is un-tinned copper > > covered with green plastic. The wire is about 11 feet high to keep it out of > the way in the common property woods area of multi building condos and > will be taken down when the weather starts to warm. > > The resistance of 135 feet of copper wire is: > #22 ga. 2.18 Ohms > #20 ga. 1.37 Ohms > #16 ga. 0.5 Ohms [snip] _________________ Topband Reflector Archives - http://www.contesting.com/_topband