The mast plate is a 6" x 1' aluminum alloy plate. It is held onto the mast by a 1" angle iron with 1" tabs welded on each side. Four 9/16" x 4" bolts run through each piece. Two pill blocks with 1" ID bearings are bolted to the mast plate. A 1" x 4' shaft runs through the bearings with 1" angle welded on each end to bolt the two horizontal pieces of the H frame to.
A Saginaw screw jack, from a TVRO dish is used for the elevation.
The position indicator is a pot mounted in an empty film canister sealed with RTV. The pot is held in place by a rod that is bolted to the mast plate and extended out to the end of the 1" shaft. A small piece of flat iron was welded to the end of the rod with a mounting hole for the pot. A piece of 1/4" ID thick walled pipe was welded to the center of the 1" shaft. I also drilled and taped a hole on the side of it so I could insert a small set screw to keep the pot shaft from slipping once it was inserted and adjusted.
The black box in the middle holds the preamp and relays.