Show Solutions Steel 30" x 30" 9mm thick plate on a 2" Raised frame with 1 welded 1-1/2" schedule 40 flange

A steel base plate, 30 by 30 inches, with a 9mm thick top plate on a 2-inch raised frame and one welded 1-1/2 inch schedule 40 flange. The flange is the receiver: a schedule 40 pipe upright drops straight into it, so the tower has a positive location rather than relying only on bolted truss. Steel rather than aluminum means significantly more mass at the base, which is exactly what you want for ballast under a self-supporting structure. The 2-inch raised frame lifts the plate for cable clearance and handling.