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SCR 270 Early Warning Radar

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Developed in Late 1930s - SCR 270

The SCR-270 radar antenna system at the National Electronics Museum in Linthicum, Maryland.

The SCR-270 radar antenna is one of two known to exist and the only one currently on display.

The SCR-270 was one of the first mobile long range early warning radar. Developed in the late 1930s, it was the US Army's primary long-distance radar throughout World War II. The US Army Signal Corps developed the radar and Westinghouse Corporation successfully developed the high power transmitter for the SCR-270 system.

Production and Cost of SCR-270s

Over four hundred radar sets were built during World War II at the Westinghouse Baltimore plant at a total cost of just under forty million dollars.1 The antenna system operated at 194MHz and could detect and track aircraft at 125 miles.

Museum SCR-270 Antenna

One of only two such antenna known to exist and the only one currently on display, this SCR-270 is a 1943 production version of the antenna that detected the incoming Japanese planes which attacked Pearl Harbor on December 7, 1941.1 It was donated to the National Electronics Museum by the Institute of Space and Atmospheric Studies, University of Saskatchewan, Saskatoon, Canada where it was used by the university to study the Aurora Borealis at frequencies of 58 and 106MHz. While at the university, it collected some of the very first radar echoes from the Northern Lights.

Primary Use of SCR-270

Photo of SCR-270 installation at Morobe, New Guinea, September 1943.

SCR-270 installation at Morobe, New Guinea, September 1943. Note the dipole arrangement of this antenna as compared to one pictured above. Photo on display at the National Electronics Museum.

SCR-270 installations were used primarily on Allied military bases for advanced warning of enemy air attacks.

Early Warning Radar in the Pacific

Photo to the right shows an SCR-270 installation at Morobe, New Guinea, September 1943, one of many installations in the Pacific Theater that served to provide early warning to Allied troops. The Japanese had begun to occupy Pacific Islands, including New Guinea, since the attack on Pearl Harbor.

The large island New Guinea was of strategic importance due to its proximity to Australia as well as its potential use for allied air bases. Battle for control of the island continued for two years, with pockets of resistance continuing until the end of WWII.

1National Electronics Museum Gallery Guide, and text from signs at the museum.

Photos taken by WW2HQ staff with permission of the National Electronics Museum.


Related pages on our website

Early radar warning ignored at Pearl Harbor