Four Frequency Cassegrain Receiver and Feed Assembly, June 1974

GB74-11521-JohnPayne-MikeBalister-KenKellermann-June1974.jpg

Description

In June 1974, John Payne (back to camera), Mike Balister, and Ken Kellermann consider the four frequency Cassegrain receiver and feed assembly, with optics designed by Peter Napier, that was the prototype system for the VLA and was also used for the VLBA. It was a new and innovative concept, first developed by the Jet Propulsion Laboratory for use on their Deep Space Network antennas, where the four feeds were offset from the electrical axis and could be illuminated by rotating the asymmetric subreflector. Here it is being installed for testing on the 140ft antenna in Green Bank. Mike says, "Judging by the way I was clutching my head [Ken] must have been giving us a hard time." Ken says he was the project scientist "assigned to hassle the Electronics Division." He adds, "Note I was comfortably sitting down and seem to be the only one that didn’t look puzzled, as appropriate for an advisor." After installation of the Cassegrain cabin on the 140 ft telescope the system was integrated and evaluated by Chuck Brockaway and Tom Dunbrack.

Creator

Records of the NRAO

Rights

NRAO/AUI/NSF

Type

Still Image

Identifier

GB74-11521-JohnPayne-MikeBalister-KenKellermann-June1974.jpg

Original Format of Digital Item

Slide

Location

Start Date

1974-06

Photo Credit

NRAO/AUI/NSF

Historical Negative #

GB74-11521

Series

Photographs Series

Unit

140 Foot Telescope Unit

Citation

Records of the NRAO, “Four Frequency Cassegrain Receiver and Feed Assembly, June 1974,” NRAO/AUI Archives, accessed February 29, 2024, https://www.nrao.edu/archives/items/show/16319.