Question: What were the first Soviet radar with circular scan, the first 3D radar and the first VHF-band 3D radar?
Answer: Innovations include the first Soviet air surveillance radar with a circular scan; the P-8 Volga (NATO: KNIFE REST A) in 1950, the first 3D-radar; the 5N69 Salute (NATO: BIG BACK) in 1975, and in 1982 the first VHF-band 3D-radar; the 55Zh6 Nebo (NATO: TALL RACK).