UPA-35 Long Range Search Radar Plan Position Indicator (PPI) Set - A Universal Long Range Radar Plan Position Indicator (PPI) set built by Hazeltine Electronics Corp., Little Neck, N. Y. In widespread service from the 1950s through the 1980s. Deployed to fixed and tactical radar sites. Four different variants were produced under different contracts. Changes included the addition of a IFF/SIF Control-Indicator and expansion of the video input capabilities. Replaced in the 1980s by the mostly solid state UPA-62.
Designed as a universal PPI scope intended for use with long range military radar sets (search and height finder) in a ground controlled intercept (GCI) environment. This was a very heavy console type set requiring 4 to 5 men to move it. Vacuum tube technology was used throughout, including a large 12" cathode ray tube as the primary display device. Mechanical indicators and positioning elements were used that are no longer used because of technology advances.
When used to direct fighter aircraft to intercept unknown or hostile aircraft, the scope was manned by a weapons director and a weapons technician working as a team. Radio and land-line equipment was used to communicate with the aircraft and ground facilities. When used as a surveillance scope, a single surveillance operator monitors an assigned area and passes aircraft track information by phone to a plotting technician behind the large plexiglass plotting boards for all to see. The scope operator will also plot selected tracks directly on the face of the scope using a grease pencil.
UPA-35 Plan Position Indicator (PPI)