Cut two 2 inch segments from a strip of aluminum angle and sanded the edges smooth. Marked each segment using the case as a template for the mounting screws. Drilled 1/4 inch holes for the compression fitting and installed four fitting for #8 screws. Mounted the angles to the case and then drilled two 1/8 inch holes in each flange facing the instrument panel. Removed the face plate of the transponder to access the mounting flange bolt. Fitted the case with the transponder installed into the opening in the instrument panel. Marked the mounting holes in the flanges on the back of the instrument panel. Removed the transponder and drilled the marked holes for 1/8 inch pop rivets. Installed the transponder case back onto the instrument panel and secured it in place with three 1/8 inch cleo's. Installed a 1/8 inch steel pop rivet in each of the mounting holes removing the cleo's in turn.
