The University of Illinois radio telescope compiled a catalog of faint extragalactic radio sources. It was a 400 x 600 foot cylindrical parabolic reflector made by covering a shaped-earth excavation with asphalt and wire screen. A catwalk at 155 feet above the ground supported about 400 conical log-spiral antennas along the focal line. Scanning in one plane was achieved by the Earth’s rotation; in the other plane by physically rotating the circularly polarized spirals.
Grote Reber’s First Radio Telescope
In a side yard of his mother’s house in Wheaton, Illinois, a 26-year old engineer named Grote Reber built the first dish antenna radio telescope in 1937. He used wooden rafters, galvanized sheet metal, and spare parts from a Ford Model T truck. With this 31-foot diameter telescope, Reber mapped the radio structure of our Galaxy, discovered bright sources of radio waves outside our Galaxy, and made the observations that would later help physicists discover non-thermal radiation.
Grote Reber’s Receiver Exhibit
On exhibit in the Green Bank Science Center in West Virginia is the original receiver equipment used by radio astronomy pioneer Grote Reber. With this, he discovered sources of radio waves coming from outside our Galaxy, mapped our Galaxy’s radio wave structure, and also made the observations that would later help physicists discover non-thermal synchrotron radiation.
Receiver Swap at Grote Reber’s First Telescope
A 26-year old Grote Reber stands on the receiver tower used to maintain and swap receivers on his homemade radio telescope in Wheaton, Illinois. He is leaning against the resonating-cavity drum of this large telescope that he built in 1937.
Grote Reber’s Telescope Equipment
A side-by-side set of photos of radio astronomy pioneer Grote Reber’s radio telescope and the control box for its receiver. The power supply is hanging on the wall. Reber used this system to map the structure of the Milky Way galaxy in radio waves. Reber donated the receiver to the NRAO in Green Bank where it is on exhibit in the Green Bank Science Center.
Giant Antenna in Nancay, France
In Nancay, France looms this enormous radio telescope. This portion of it is a section of a sphere that reflects the radio waves to a focus off to the left. It observes supernova remnants, star-forming regions, pulsars — really, anything that a more familiar dish-shaped radio telescope can see. In 1973, this telescope worked with our 140-foot telescope to observe the chemistry of Comet Kohoutek 1973 XII. They discovered OH, hydroxide, in the comet’s gaseous envelope.