XAF Radar Antenna

XAF Radar Antenna (HM2F9W)

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N 39° 11.72', W 76° 41.087'

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The Naval Research Laboratory developed and constructed the experimental XAF radar in 1938.

It was installed on the battleship USS New York for winter maneuvers in the Caribbean in early 1939. After nearly three months of constant operation, averaging almost twenty hours daily, the XAF's performance and reliability exceeded expectations. It detected aircraft up to 100 nautical miles away from ships out to 15 nautical miles. The USS New York's crew employed radar for navigation and in gunnery practice, spotting the fall of shot and even tracking projectiles in flight. The Commander of the Atlantic Squadron, ADM A.W. Johnson, stated, "The XAF equipment is one of the most important military developments since the advent of radio itself."

Later in 1939, the Radio Corporation of America (RCA) reengineered the XAF and placed it in production. RCA delivered six of these production models, designated CXAM, and the Navy installed them on six ships. RCA produced an improved version with a simplified antenna, the CXAM-1, in greater numbers.

After proving its merit on the USS New York, the Navy returned the XAF antenna to the Naval Research Laboratory and used it in additional experiments. In 2009 the Navy loaned the XAF to NEM. The XAF looks as it did on the USS New York in 1939. On the back side there

are two metal strips that may have been added during later tests.

Additional Facts

· The XAF operated at a frequency of 200 MHZ
· Brewster Aeronautical Corp. manufactured the mechanical structure
· The XAF detected large birds during the 1939 test
· The XAF antenna contains 42 half wave radiating elements backed by the same number of reflectors
· Because of its size and appearance, sailors dubbed the XAF the "flying mattress"
· The XAF cost less than $17,000 to design and build
HM NumberHM2F9W
Placed ByNational Electronics Museum
Marker ConditionNo reports yet
Date Added Sunday, March 31st, 2019 at 8:02am PDT -07:00
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Locationbig map
UTM (WGS84 Datum)18S E 354509 N 4339805
Decimal Degrees39.19533333, -76.68478333
Degrees and Decimal MinutesN 39° 11.72', W 76° 41.087'
Degrees, Minutes and Seconds39° 11' 43.2" N, 76° 41' 5.2200000000002" W
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