[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 30: Microwave and Millimeter Wave Applications in the 1970s and 1980s

[ECCB receiver]

Photo of an ECCB receiver. Each cryogenically cooled receiver is packaged in a cylindrical enclosure consisting of an upper dewar section and a lower cylindrical section which contains cooling equipment and miscellaneous active electronic components. The receivers are mounted to the bottom of the GOMUX by means of lock ring attachment incorporated within the upper mounting plate of each receiver. The feed enclosure projects upward through the mounting plate. The top surface is a quartz window which preserves the dewar vacuum and allows low loss transmission of the received signal into the receiver scalar feed-horn. A spring loaded snap bolt engages an indent in the mounting plate to insure that the receiver is appropriately positioned to accept the polarized signal which is reflected downward from the GOMUX optical table into the receiver's scalar feed-horn. Access to the components located in the cylindrical section below the dewar is obtained by removing the cylindrical cover. Credit: Photo courtesy of Doc Ewen.

Slide 31
Modified on Saturday, 26-Mar-2005 18:11:32 EST by Ellen Bouton