Doc Ewen: The Horn, HI, and Other Events in US Radio Astronomy

Slide 11: Detecting the Interstellar Hydrogen Line, 1951

The design of the horn antenna was based on descriptive information presented in the Rad Lab book on Antennas by Sam Silver [Microwave Antenna Theory and Design, edited by Samuel Silver. MIT Radiation Laboratory Series 12, published by McGraw-Hill, 1949; reprinted by P. Peregrinus on behalf of the Institution of Electrical Engineers, 1984]. The maximum size was determined by the geometric constraints of the fourth floor parapet at Lyman Lab. I sent my calculations and sketches to Sam for a sanity check, before sending the build order to the Physics Dept. Model Shop. It was up on the parapet in about three weeks. [Diagrom courtesy of Doc Ewen]
Slide 12