- 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|2; its successor, the XAF, installed in December 1938 on the battleship USS|New York|BB-34|2; and the firstRCA -designed system, the CXZ, installed in December 1938 or January 1939 on the battleship USS|Texas|BB-35|2. 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|2, the aircraft carrier USS|Yorktown|CV-5|2 (in September 1940), and the heavy cruisers USS|Pensacola|CA-24|2, USS|Northampton|CA-26|2, USS|Chester|CA-27|2, and USS|Chicago|CA-29|2.cite journal|author=Macintyre, Donald, CAPT RN |title=Shipborne Radar |publisher=United States Naval Institute Proceedings |date=September 1967] 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|2, USS|West Virginia|BB-48|2, USS|North Carolina|BB-55|2, and USS|Washington|BB-56|2; on the aircraft carriers USS|Lexington|CV-2|2, USS|Saratoga|CV-3|2, USS|Ranger|CV-4|2, USS|Enterprise|CV-6|2, and USS|Wasp|CV-7|2; on the heavy cruiser USS|Augusta|CA-31|2; on two light cruisers; and on the seaplane tender USS|Curtiss|AV-4|2.
Radar detection range of aircraft depends on altitude, size, and number of aircraft. 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 thebattle 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 theImperial Japanese Navy 's lack of wide-spread use of radar on its ships.Notes
References
* [http://www.history.navy.mil/library/online/radar-1.htm U.S. Radar, Operational Characteristics of Radar Classified by Tactical Application, FTP 217]
* [http://www.radarworld.org/america.html History of US radar development.]
* [http://www.vectorsite.net/ttwiz_02.html History of US radar development, with more detail on CXAM.]
* [http://users3.ev1.net/~cfmoore/operating%20systems/RADARUNITS/cxam/cxam-1.htm Initial installations of CXAM.]
* [http://www.users.bigpond.com/pacificwar/Yorktown/beforePearlHarbor.html Date of Yorktown installation.]
* [http://www.ww2pacific.com/friendly.html Date of Yorktown testing with CXAM.]
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