AMES Type 80 design intended for all of the northern bases became the Mark II. As early as 1950, the RAF had considered several solutions to the original Phase II GCI requirement, including the Royal Navy's new Type 984 radar, the Army's Orange Yeoman, and an adaptation of the Type 80. By mid-1953, the Air Ministry made the firm decision to use the Type 80-derived Type 81 rather than the other designs. Because the Type 81 spread its signal over a much greater vertical angle, the amount of energy in any one angle was lower. This meant the design would have less range
Type 97 90 mm Infantry Mortar on the Type 94. Certain compromises in material and workmanship were made in the manufacture of the Type 97. The bipod feet and chain hooks were held to the legs of the bipod by pins, joined with solder, whereas on the Type 94 they are welded. No welds were polished on the Type 97, although no indications of fractures were reported despite the poor quality of the welding. The adjusting nut, sliding bracket, and hand wheels of the Type 97 are made of steel, rather than brass which was utilized in the Type 94. Type 97 90 mm Infantry Mortar