Feed horn and secondary reflector of 85 ft <a href="https://en.wikipedia.org/wiki/Cassegrain_antenna" class="extiw" title="w:Cassegrain antenna">Cassegrain antenna</a> at <a href="https://en.wikipedia.org/wiki/Goldstone_Deep_Space_Communications_Complex" class="extiw" title="w:Goldstone Deep Space Communications Complex">Goldstone Deep Space Communications Complex</a>, California in 1963.  This is a view from the bottom of the 85 ft diameter dish antenna,  which is facing up, showing the feed. The radio waves from the spacecraft  reflect off the dish to the small convex secondary reflector supported on the booms at top, then are reflected into the exponential feed horn inside the white pillar. where they are conducted through a waveguide to the receiver.
James Joseph
1963-06
Retrieved June 3, 2015 from <a rel="nofollow" class="external text" href="https://books.google.com/books?id=8yADAAAAMBAJ&amp;pg=PA67">James Joseph, "Ranger 6, Where Are You" in <i>Popular Science" magazine, Popular Science Publishing Co., New York, Vol. 182, No. 6,  June 1963,  p. 67</i></a><i> on Google Books</i>