1 & 2: The 37-pin d-sub and coax antenna COM connectors were installed to the GTR200 backplate, then the backplate was installed to the GTR 200 Rack. 3: The GTR 200 rack and L & R XPNDR brackets were installed onto the existing brackets and racks. 4: The GTX 35R rack was installed onto the XPNDR brackets.