I built a small 10 meter vertical as a test and gee wally it tunes nice at 28.520 mhz 50 ohm impedance. I have a very nice 1:1 Current isolation balum from balum works. Is there any reason one cannot be used on a vertical unlike a dipole? Or would something else be better such as ferrite beads? it is 4 feet off ground on PVC made of half hamstick three #14 insulated wire radials. Go figure after year of frustration this works but my wore antenna never has!!! Happy Holidays all 73's TNX all who have bee helpful here.