Thanks to those who replied to my earlier question:
"Is there a distance -- minimum, optimal or maximum --- that a vertical's
feed point should be from the earth for a ground-mounted radial system?"
In my effort to make the question as simple as possible, I left out why I
wanted to know. It's basically to get the connection and any matching out
of harm's way... above occasional high water and possible bumps by the
lawnmower, etc. Kinda the Southern version of the snowdrift problem
described by W1FV. I want the feed point about 18-24" above the earth to
avoid these problems... as opposed to "right at earth".
This is just a simple "classical" vertical... insulated from the base and
the shield of the coax will tied to ground and the radials.