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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 PPI Operator Controls.

UPA-35 Plan Position Indicator (PPI)

UPA-35 Plan Position Indicator (PPI)
Element Value Notes
Nomenclature UPA-35
Manufacturer Hazeltine Electronics Corp.
Type Universal Search PPI
PRF 200 to 600 pps
Trigger Pulse Width 0.5 to 6.5 µsec
Video Input 1 to 2.5v, video, IFF and beacon
Delayed Sweep 4 to 200 mi
Video Off-Centering 0 to 250rmi in any azimuth
Power 115 vac, 55 to 65 cps, 1-ph, 1.82 kva
Range 10 to 250 mi, variable manually Type 1
Range 10 to 300 mi, variable manually Type 2-4
Display Device 12" Cathode Ray Tube
UPA-35 at Peterson AFB Museum

UPA-35 Components (edit list)
Component Model Quantity Height Width Deep Weight Notes
Azimuth and Range Indicator IP-207
Electronic Switch SA-376
Control-Indicator C-2055/UPA-35 IFF/SIF Control Box
Desk Shelf MX-1383/UPA-35
Cathode Ray Tube Window MX-1845/UPA-35
Power Supply PP-1113/UPA-35
Power Supply PP-849/UPA-35
Video Amplifier AM-991/UPA-35
Video Amplifier AM-992/UPA-35
Video Amplifier AM-993/UPA-35
Electronic Control Amplifier AM-994/UPA-35
Electronic Control Amplifier AM-995/UPA-35
Electronic Control Amplifier AM-996/UPA-35
Pulse Generator TD-105/UPA-35
Range Calibrator TD-106/UPA-35
Sweep Generator TD-107/UPA-35
Electronic Gate TD-108/UPA-35

See Also:


  • Winkler, David F., Searching the Skies: the Legacy of the United States Cold War Defense Radar Program, USAF Hq Air Combat Command, 1997, 192 pages, Pdf
  • MIL-HDBK-162A, 15 Dec 1965.
  • Aerospace Control and Warning Systems Operator, AFSC 27650, Atmospheric Systems, Vol 4, USAF Extension Course Institute, Air University, Maxwell AFB, Alabama. Online at Google Books.


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