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FPS-3 Long Range Search Radar Set - A long range search radar manufactured by the Bendix Radio Division of Bendix Aviation Corporation and deployed to long range radar sites in the 1950s. Equipped with Moving Target Indicator (MTI) and normally employed as part of an aircraft early warning network. Capable of detecting heavy bomber aircraft at a range of 200 to 300 miles and a height of approximately 40,000 to 60,000 feet depending on the range. Operates in temperatures ranging from -67 deg F to plus 140 deg F with humidity up to 100 percent and at altitudes from sea level to 7,000 feet. Variants include the FPS-3A, the FPS-508 Canadian version and the MPS-7 Mobile Version.

The antenna was normally mounted on either a temperate tower or an arctic tower and usually covered with an inflated radome on the arctic tower. Air pressure kept the radome inflated and access to the antenna deck was through an airlock. In colder climates the antenna bubble also had heat banks to keep snow and ice off the bubble. The two transmitter groups and other components were mounted on a rotating frame below the antenna sail.

Othello AFS, two FPS 6 Height Finder Radars on the left, FPS 3 Search Radar in the bubble and Operations building on the right, circa 1959
FPS-3 search radar
Element Value Notes
Nomenclature FPS-3
Origins CPS-5 Disputed
Variants FPS-3A
MPS-7 Mobile Version
FPS-508 Canadian Version
Manufacturer Bendix Radio Division of Bendix Aviation Corporation
Type Search
Number Made 49~
Frequency 1220 to 1365 MHz
PRF 440
Pulse Width 3 or 6 us
Rotation Speed 3.3, 5, 6.6, 10 RPM
Power 650 Kw 5J26 magnetron
Range 220 nmi Long Range
Resolution 0.5 mi
Altitude 60,000 ft
Introduced 1950
FPS-3 Radar Set on a Temperate Tower
FPS-3 System Components

FPS-3 Components (edit list)
Component Model Quantity Height Width Deep Weight Notes
Antenna Reflector AT-251/FPS-3 1 480 230 156
Pedestal AB-180/FPS-3 1 63 66 108
Antenna Support AB-179/FPS-3 1 160 89 101
Antenna Horn AS-488/FPS-3 1 96 60 138
Transmitter Group OA-398/FPS-3 2 42 39 43 600
Oscilloscope OA-17/FPS-3
Receiver Group OA-176
1 59 27 28 450
Indicator Group OA-175/FPS-3 0-12 44 24 45 412
Indicator Group OA-188/FPS-3
1 48 21 26
Radar Control Group OA-179/FPS-3 1 60 23 26
Generator Group OA-174/FPS-3 1
Display-Plotting Board Group OA-289A/G
1 21.25 15.25 10.125
Telephone Central Group AN/GTA-3 1
Towers AB-178/FPS-3 (Temperate)
AB-196/FPS-3 (Temperate)
AB-199/FPS-3 (Arctic)
AB-199A/FPS-3A (Arctic)
1 300 264 480 14,000

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, Pdf.


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