I have used KBS products on antennas, so far no issues. Painted 102" and many other smaller antenna whips with this:
KBS Top Coat
It is available in Flat Black, OD green, Camo Brown and Desert Tan. I have painted 2 vehicles with it as well. So far it has been a good choice.
I prepped the whips with a wire wheel, removed any dirt and contamination the entire length. After that, wipe it off several times with MEK removing the remaining residue. A couple of light coats seem to be better than a single heavy coat.