[TowerTalk] base for very short Rohn 25G

[Dave NØRQ]

I don't believe Rohn gives specs for something this short,
so I'm asking for advice (not PE specs) for a short Rohn 25G.

This will be for satellite antennas: a couple of beams, total of
roughly 6-7 square feet.  The Rohn 25G will be 20' tall, and will
have a mast out of the top of about 5-7'.  It will be one normal
section and one flat-top (25AG4) section, sitting on top of
a hinged short base (SBH25G).

The tower will also be attached to the house at about 8' off
the ground.

What size hole do I need for the base?  (I know to have plenty
of gravel in the bottom for drainage.)  Other suggestions 
welcome as well.

Thanks & 73,
Dave N0RQ