[Doc Ewen looks into the horn antenna, 1950]
Image courtesy of Doc Ewen


Harvard Cyclotron: 1948-1951

Detection of HI Line: 1951

Harvard 24ft and 60ft and NRAO founding: 1952-1956

1950s and 1960s: Two Roads that Crossed

Microwave & Millimeter Wave Applications in the 1970s and 1980s

Mm Wave Radiometry in the 1990s

May 2001 visit to NRAO Green Bank



[Doc Ewen and horn antenna, 2001]
Image courtesy of Doc Ewen

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

by Doc Ewen, © 2003

Slide 14: Detecting the Interstellar Hydrogen Line, 1951

[Purcell letter to Shapley]

Page 2 of Purcell's funding request letter, with itemized list including antenna ($150), APT-5 xmtr ($100), power supply ($75), mixer parts ($100), and waveguide ($75), for a grand total of $500. [Photo courtesy of Doc Ewen]

Slide 15
Modified on Monday, 06-Sep-2004 14:13:00 EDT by Ellen Bouton