Lichtenstein SN-2 AI radar installation. Although Telefunken had not been previously involved with radars of any type for fighter aircraft, in 1944 they started the conversion of a Marbach 10-cm set for this application. Downed American and British planes were scavenged for radar components; of special interest were the swiveling mechanisms used to scan the beam over the search area. An airborne set with a half-elliptical radome enclosed dish antenna, code-named FuG 240 Berlin was completed in January 1945, and about 40 sets were built and placed on night-fighter aircraft. A few sets, code named Berlin-S, were also built for shipboard surveillance. Japan In the years prior to World War II, Japan had knowledgeable researchers in the technologies necessary for radar; they were especially advanced in magnetron development. However, a lack of appreciation of radar's potential and rivalry between army, navy and civilian research groups meant Japan's development was slow. It was not until November 1941, just days before the attack on Pearl Harbor, that Japan placed into service its first full radar system. In August 1942, U.S. marines captured one of these first systems, and, although crude even by the standards of early U.S. radars, the fact the Japanese had any radar capability came as a surprise. Japanese radar technology was 3 to 5 years behind that of America, Great Britain, and Germany throughout the war. A major leader in early technology development was Hidetsugu Yagi, a professor and researcher of international status. His papers in the late 1920s on antennas and magnetron design were closely studied by scientists and engineers worldwide. He was allowed no part, however, in developing Japan's wartime radars. His earlier work was given so little attention by the Japanese military that, when they received a captured British radar set, at first they were unaware that the "Yagi" mentioned in accompanying notes referred to a Japanese invention. Although Japan had joined Nazi Germany and Fascist Italy in a Tripartite Pact in 1936, there had been essentially no exchange of technical information. This changed in December 1940 when a group of Japanese officers representing Army technology was allowed to visit Germany, followed in January by a similar group from the Navy. In the visit, the Japanese were shown some German radars and a British MRU (their earliest searchlight-control radar), left behind during the Dunkirk evacuation. In addition, German-educated Yoji Ito, leader of the Navy delegation, was