SCR-268

The SCR-268 (for Signal Corps Radio no. 268) was the US Army's first radar system. It was developed to provide accurate aiming information and used in gun laying systems and directing searchlights against aircraft.

The system was already considered out of date by the end of World War II, having been replaced by the much smaller and more accurate SCR-584 microwave-based system after the Tizard Mission provided the US with the cavity magnetron.

The Signal Corps had been experimenting with some radar concepts as early at the late 1920s, under the direction of Colonel William R. Blair, director of the Signal Corps Laboratories at Fort Monmouth, New Jersey. While most of the Corps' efforts revolved around infra-red detection systems (a popular idea at the time), as well as a newer generation of sound detectors, they also maintained a small program of research on microwave radars based on the "beat principle", in which an aircraft would cause two signals to interfere. Low generator efficiency and a lack of ranging capability made these efforts impractical.

In 1935 one of Blair's recent arrivals, Roger B. Colton, convinced him to send an engineer to investigate the US Navy's CXAM radar project. The navy's system traced its development from experiments conducted by Albert H. Taylor and Leo C. Young at the United States Naval Research Laboratory in the early 1920s. William D. Hershberger duly went to see what they had, and returned an extremely positive report. They decided to try to find a need for such a unit in order to gain funding, and eventually received a "request" by the Chief of Coast Artillery on February 1, 1936 for a gunlaying system with a range of 15,000 yards through rain, mist, smoke or fog.

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