Cecil Moore wrote in news:6F0Ih.1335$FG1.829
@newssvr27.news.prodigy.net:

How do you guys model the parasitic effects of
a tower? With its base in concrete, it is neither
floating nor grounded. Is there some sort of
modeling rule for such?

For instance, if a vertical with sloping radials
is mounted on a tower with the radials insulated
from the tower, the tower still has an effect.
If we model the tower as mininec grounded, it has
some extreme effects which may not be realistic.

I know that some assert that a metal tower structure in concrete
foundations is effectively earthed for lightning protection, wouldn't you
also have some form of additional lightning protection that the RF effects
would be important to include in your model?

Owen