On Sat, 28 Feb 2009 17:41:22 -0600, MTV
wrote:

The tower and beam will be well grounded.

Hi Marv,

Take advantage of an excellent opportunity to create an "Ufer Ground."

In a nutshell, when you put in the rebar, weld each piece to the
others for continuity, and then make provision for a wire (either
securely clamped, or likewise welded) connection to the assembly that
is accessible for further connection outside of the block of concrete.
This wire will be a low Ohmic ground lead.

possibly drill a hole for a bolt through the 15" dia trunk?

This should be robust, but think carefully about how those guys span
out towards the trees. If they are not dead-on in angle away from the
tower (as a function of their tower connection) you may twist the
tower and weaken it.

I have no idea how secure the header is

Will that statement go into an insurance claim? Houses are not built
for lateral strength. Not only does the wall lack the stiffness of
your Oak trees, it is far closer to the moment arm (think crowbar).

73's
Richard Clark, KB7QHC