drove the design to frequencies as high as possible. The reflex klystron (as it was later called) had just been developed by Nikolay Devyatkov. Using this, design was started on a set designated Gneis (Origin) and operating at 16 cm (1.8 GHz). When the NII-9 was evacuated to Moscow in July 1941, this greatly affected the schedule. Also, the reflex klystron had not been put into production and its availability in the future was doubtful; therefore, the project was terminated. The need, however, for an airborne radio-location set was now even more important; the Pe-3, a heavy fighter variant of the Pe-2, was in production. Some of these aircraft were being configured as night-fighters, and the radar (as it was now called) was urgently needed. The NII-20 and Factory 339 took up the design, led by the Technical Director, Victor Tikhomirov. The new set, designated Gneiss-2 (Гнейс-2), operated at 1.5 m (200 MHz). The Pe-3 fighter was a two-place aircraft, with the pilot and the rear gunner/radio operator seated back to back. The radar was designed as another piece of equipment for the radio operator. The antennas were mounted above the top surface of the wings, a broad-pattern transmitting array on one wing and two Yagi receiving antennas on the other. One Yagi was directed forward and the other, a few feet away, aimed outward 45 degrees. The fuselage of the aircraft provided a shield between the transmitting and receiving antennas. The system had a range of about 4 km and could give the target's azimuth relative to the fighter's flight path. The Gneis-2, the first aircraft radar in the Soviet Union, was proven in combat at Stalingrad during December 1942. About 230 of these sets were built during the war. A few were installed on Yak-9 and (out of number sequence) Yak-3 aircraft, the advanced fighters that eventually gave the VVS parity with the Luftwaffe. Other sets with Gneis designations were developed at Plant 339 for experimental purposes, particularly with Lavochkin La-5 fighters and Ilyushin Il-2 ground-assault aircraft, but none of these sets were placed into production. Naval During the 1930s, the RKKF (Red Fleet) had major programs in developing radio communications. Starting in 1932, this activity was headed by Aksel Ivanovich Berg Director of the NIIIS-KF, Red Fleet Signals Research) and later given the rank of Engineer-Admiral. He was also a professor at Leningrad's universities and closely followed