The antenna for CXAM radar mounted on the foretop of the U.S. Navy aircraft carrier USS <i>Yorktown</i> (CV-5). Photographed during the Battle of Midway, 4 June 1942. The antenna and its supporting yoke are somewhat obscured by the upper structure of the foretop, the topmast, the mast's yard (with a ladder hanging from it and signal balls on two of its halliards) and the U.S. ensign flying from the mast.
USN
Official U.S. Navy photo <a rel="nofollow" class="external text" href="http://www.history.navy.mil/our-collections/photography/numerical-list-of-images/nara-series/80-g/80-G-310000/80-G-312018-A.html">80-G-312018-A</a> from the U.S. Navy <a rel="nofollow" class="external text" href="http://www.history.navy.mil">Naval History and Heritage Command</a>