CXAM radar



The CXAM radar system was the first production radar system deployed on United States Navy ships. It followed several earlier prototype systems, such as the NRL radar installed in April 1937 on the destroyer USS Leary (DD-158); its successor, the XAF, installed in December 1938 on the battleship USS New York (BB-34); and the first RCA-designed system, the CXZ, installed in December 1938 or January 1939 on the battleship USS Texas (BB-35). Based on testing in January 1939, where the XAF was more reliable, the US Navy ordered RCA to build six XAF-based units for deployment and then shortly thereafter ordered 14 more.

The first six units RCA produced (delivered in 1940) were denoted "CXAM" and were a fusion of XAF and CXZ technologies. These were installed on the battleship USS California (BB-44), the aircraft carrier USS Yorktown (CV-5) (in September 1940), and the heavy cruisers USS Pensacola (CA-24), USS Northampton (CA-26), USS Chester (CA-27), and USS Chicago (CA-29). The next 14 units RCA produced (also delivered in 1940) were denoted "CXAM-1" and were slight improvements over the CXAM design. These were installed on the battleships Texas (in October 1941), USS Pennsylvania (BB-38), USS West Virginia (BB-48), USS North Carolina (BB-55), and USS Washington (BB-56); on the aircraft carriers USS Lexington (CV-2), USS Saratoga (CV-3), USS Ranger (CV-4), USS Enterprise (CV-6), and USS Wasp (CV-7); on the heavy cruiser USS Augusta (CA-31); on two light cruisers; and on the seaplane tender USS Curtiss (AV-4).

Radar detection range of aircraft depends on altitude, size, and number of aircraft. Surface ships are more difficult to detect due to ground clutter, and require shorter ranges. The CXAM is listed (in U.S. Radar, Operational Characteristics of Radar Classified by Tactical Application) as being able to detect single aircraft at 50 miles and to detect large ships at 14 miles. Other sources list CXAM detection range on aircraft out to 100 miles. Lexington ' s CXAM-1 detected the incoming Japanese carrier aircraft strike at a range of 68 miles during the battle of the Coral Sea.

The US Army's first non-prototype radar system, the SCR-270 radar, was developed in parallel with the CXAM.

The US Navy's use of radar was an important advantage in World War II compared to the Imperial Japanese Navy's widespread lack of radar on its ships.