[TowerTalk] Foundation Question

[Art Trampler]

Greetings Gang,

I am the new owner of an old but well maintained Tri-Ex TM-358 (not C).

The base is nearly completely per the Tri-Ex blueprints with one change: I am using #6 rebar instead of #5, as Grade W/A706 was only available in my city in #6.
 
Here is the question: The prints do not show any other rebar cage for the foundation. If I am fortunate, the hole will be 36" x 36" x 72". The base plate is  22" square and the the rebar roughly 20".
 
I think it is wise to construct a separate cage (perhaps wired to it) that will go around the perimeter of the hole, perhaps 4" from its edge, in four layers/levels.

What do you think? Overkill or thinking right?
 
73,
Art K0RO
Springfield, MO