<i>Royal Air Force Radar, 1939-1945.</i><br>
Air Interception radar:  AI Mark VIIIA scanner unit mounted on the nose of a Bristol Beaufighter Mark VIF night fighter.  The transmitter unit is not shown, but was fitted to the mounting tray underneath the scanner mechanism.  Operating at a frequency of 3 GHz (10 centimeters wavelength) powered by the new <a href="https://en.wikipedia.org/wiki/magnetron" class="extiw" title="w:magnetron">magnetron</a> tube invented by John Randall and Harry Boot at Birmingham University, UK in 1940, this was the first <a href="https://en.wikipedia.org/wiki/microwave" class="extiw" title="w:microwave">microwave</a> <a href="https://en.wikipedia.org/wiki/air_intercept_radar" class="extiw" title="w:air intercept radar">air intercept radar</a>, used on British warplanes in World War 2 beginning late 1941.  The development of microwave radar was a game changer for the Allies during World War 2, credited with significantly shortening the war.
Royal Air Force official photographer
between 1939 and 1945 <div style="display: none;">date QS:P,+1950-00-00T00:00:00Z/7,P1319,+1939-00-00T00:00:00Z/9,P1326,+1945-00-00T00:00:00Z/9</div>
<p>Cropped version of <a rel="nofollow" class="external free" href="http://media.iwm.org.uk/iwm/mediaLib//53/media-53740/large.jpg">http://media.iwm.org.uk/iwm/mediaLib//53/media-53740/large.jpg</a>
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<td>This photograph <a rel="nofollow" class="external text" href="https://www.iwm.org.uk/collections/item/object/205210771">CH 16665</a> comes from the collections of the <a rel="nofollow" class="external text" href="https://www.iwm.org.uk/">Imperial War Museums</a>.
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