Existing National Historic Landmarks
The Reber Radio Telescope was designed and built by Grote Reber in 1937 for his personal use in conducting research in the newly emerging field of radio astronomy. The original location of the telescope was in the backyard of his house at 212 West Seminary Road, in Wheaton, Illinois. Grote Reber's house is no longer extant. The entire block of 200 West Seminary Road, in Wheaton, Illinois, was demolished during the 1950s to construct a public park.
The telescope was originally a 31 foot 5-inch transit-mounted parabolic radio telescope reflector made from 72 wooden radial rafters, covered with skin of 26 gauge point iron (focal length: 20 feet), and 2 elevated arches positioned on railroad wheels to permit changes in elevation angles. The telescope took about 4 months to build and weighed about 2 tons when completed.
Reber used the telescope from 1937 to 1948 when he sold it to the National Bureau of Standards which moved it to an observing site in Sterling, Virginia. After the telescope was moved to Sterling, the National Bureau of Standards mounted the entire instrument on a turntable thus changing the original transit design to an altazimuth design.
In 1952 the telescope was disassembled and shipped to another observing site in Boulder, Colorado. Finally, in 1957, it was acquired by the National Radio Astronomy Observatory, in Green Bank, West Virginia, where in 1959-60 it was reassembled under Grote Reber's personal supervision. Some wooden parts were found deteriorated and replaced during this process. The telescope now stands on its 1948 turntable to the left of the entrance road of the National Radio Astronomy Observatory, in Green Bank, West Virginia, in proximity to the Karl Guthe Jansky Replica Antenna and the Ewen-Purcell Antenna.
With the exception of the change of mounting from the transit design to the altazimuth design and the replacement of some deteriorated wooden support members, the telescope retains its integrity from the period of its first use by Grote Reber in 1937-48. The telescope is in good condition and can be used for radio astronomy if needed.
In 1972 the telescope was listed on the National Register of Historic Places by the Antiquities Commission of the State of West Virginia. 
The Reber Radio Telescope was the first parabolic antenna specifically designed and built to do research in the newly emerging field of radio astronomy. The telescope was designed and built by Grote Reber, an amateur astronomer and electronics expert from Wheaton, Illinois , who from 1937 until after World War II, was the world's only active radio astronomer. The telescope design is the forerunner of the majority of present day radio telescopes.
Until the 20th century, astronomers were limited to what they could see or photograph in the visible spectrum of light--a relatively narrow band of wavelengths. This all changed in 1932, when Karl Jansky, a radio engineer at Bell Laboratories in Holmdel, New Jersey, was the first to establish that radiation at radio wavelengths was reaching the earth from interstellar space. 
Jansky joined Bell Laboratories in Holmdel, New Jersey, in 1928 and began studying static and other noises affecting Bell System transoceanic radio telephone circuits. In 1929 he designed and built a 14.6 meter-rotatable, directional antenna system to study radio noise. Two years later he was able to classify the noise into three types: that due to local thunderstorms; that due to distant thunderstorms; and a steady hiss of static, the origin of which was not known.
This unknown static fascinated Jansky because its source could not be traced to any location on the earth or in the solar system. He made an extensive study of the noise in 1932, finding that it varied not every 24 hours but every 23 hours and 56 minutes. This is the period of the earth's sidereal day, a day defined by the earth's rotation relative to the stars, not the sun. Therefore the source of the noise was outside of the solar system and fixed in space. After discussing this information with an astronomer, Jansky concluded that the static was coming from the center of our galaxy, the Milky Way.Jansky published his findings in scientific journals, and, on May 5, 1933, The New York Times carried his discovery on the front page. Jansky's discovery of the existence of interstellar radio waves with his antenna liberated astronomers from the confines of optical astronomy and opened up the radio portion of the electromagnetic spectrum for productive research. The longer radio waves could penetrate not only the earth's atmosphere, but also clouds of interstellar dust that previously had obscured large sections of space. When Jansky was not allowed to continue with basic research into the field of radio astronomy by Bell Laboratories, another pioneer, Grote Reber, continued his work.
Grote Reber read Jansky's papers and was one of the first scientists to appreciate the significance of Jansky's discovery. To quote his own words:
Reber's decision to continue Jansky's work meant that he would have to design and build the world's first radio telescope. Since no one had ever done this before, Reber was on his own. After studying the problem, he decided to construct a large parabolic reflector with the intention of observing at a very short wavelength, about 10 cm. He realized that a parabolic reflector would have the advantage of providing a narrow symmetrical beam and would also enable the wavelength to be altered simply by changing the receptor at the focus. In the choice of operating wavelength Reber was guided by two considerations: he could achieve better angular resolution and the radiation should be stronger at shorter wavelengths.
With these considerations in mind, Reber began to build the first radio telescope specifically designed for radio astronomical observations. Since he had no outside source of funding to build his telescope he had to do all of the work by hand in his own backyard. Reber originally preferred a full steerable mounting, but this was far too expensive, so he decided on a meridian transit instrument steerable in elevation only, relying on Earth's rotation to scan the heavens. While he wanted as large a reflector as possible, Reber had to balance the cost with his resources and finally decided on a sheet metal surface of 31-foot diameter, to be mounted on a wooden supporting structure for the sake of cheapness and ease of construction. The reflector surface consisted of 45 pieces of 26-gauge galvanized iron sheet screwed on 72 radial wooden rafters cut to parabolic shape. Reber cut, drilled and painted all of the parts. Except for the part-time assistance of two men on foundations and erections, Reber personally put together the radio telescope piece by piece, and completed the entire job in four months from June to September 1937. The final telescope cost Reber $4,000.
During the decade after 1937 Reber, using his telescope, worked practically alone in the field of radio astronomy. By 1940 he confirmed Jansky's conclusion that the Milky Way is a source of radio radiation, and in 1944 he published in the Astrophysical Journal the first contour maps of radio brightness of the Milky Way as it appears at a wavelength of 1.87 meters. He discovered discrete sources of radio emission in the galactic center, Cygnus, and Cassiopeia, as well as radio waves from the sun. From 1937 until after World War II Reber was the world's only active radio astronomer.
Reber's Radio Telescope stands today as a monument to Grote Reber, a pioneer in the field of radio astronomy. With the construction of his telescope, Reber demonstrated his persistence in overcoming technical difficulties and his determination to do pioneering work in the field of radio astronomy. Grote Reber's work from 1937 to 1948, using the radio telescope he personally designed and built, demonstrated the importance of Jansky's discovery, and forever changed the science of astronomy.
1. The descriptive material for this section was taken from the following sources:
2. The material for the statement of significance was taken from the following sources:
Aaronson, Steve. "Radio Astronomy and the Big Bang," Bell Laboratories Record. January 1979, pp. 6-11.
Abell, George O. Exploration of the Universe. 4th ed., Philadelphia: Saunders College Publishing, 1982.
Asimov, Isaac. Asimov's Biographical Encyclopedia of Science and Technology. 2nd ed. , New York: Doubleday & Company, Inc. , 1982.
Hey, J.S. The Evolution of Radio Astronomy. New York: Neale Watson Academic Publications, Inc., 1973.
Historical Radio Telescopes at the National Radio Astronomy Observatory in Green Bank, West Virginia. Green Bank, West Virginia: Associated Universities, Inc., no date.
Kellerman, K., and B. Sheets, ed., Serendipitous Discoveries In Radio Astronomy. Green Bank, West Virginia: National Radio Astronomy Observatory/Associated Universities, Inc., 1983.
Kirby-Smith, H.T. U.S. Observatories: A Directory and Travel Guide. New York: Van Nostrand Reinhold Company, 1976.
Kraus, John. "The First 50 Years of Radio Astronomy, Part 1: Karl Jansky and His Discovery of Radio Waves from Our Galaxy," Cosmic Search, Fall 1981, pp. 8-12.
Learner, Richard. Astronomy Through the Telescope. New York: Van Nostrand Reinhold Company, 1981.
Oref, Wallace R. "National Register of Historic Places Inventory-Nomination Form--Reber Radio Telescope." Green Bank, West Virginia: National Radio Astronomy Observatory, 1972.
Struve, Otto, and Zebergs, Velta. Astronomy of the 20th Century. New York: Macmillan Company, 1962.
Ronan, John J. "An Oracle Comes of Age: The National Radio Astronomy Observatory," Ham Radio Horizons, May 1977, pp. 12-16.
The National Radio Astronomy Observatory. Green Bank, West Virginia: National Radio Astronomy Observatory/Associated Universities, Inc., 1988. (Brochure)
(click on the above photographs for a more detailed view)