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 90 Kyū-maru procurement plan was established in the 1980s while Japan was experiencing asset price bubble. After the asset price bubble burst in 1991 and the collapse of Soviet Union in 1992, Japan started to cut its defence budget. In order to save budget for Kongo Class missile destroyers and other new weapons, Japan made a plan to reduce the size of its tank force. The production of Type 90 therefore slowed down and part of its budget was shifted to the research and development of the new Type 10 main battle tank. Being 12 tonnes heavier than its predecessor Type 74