Wayne wrote:
Thanks for the ideas.
The question was prompted because I don't want to take the antenna down for
a check or repair, and I don't know how well my readily available materials
hold up under UV and heat.

How useful is it to have plastic tip caps on an antenna you cannot reach?

I could understand that you would want a spherical tip end to reduce
the risk of arcing, but it would need to be metallic and would not suffer
from UV or heat.