After all his studies, Reber constructed the first radio telescope in September of 1937. Reber was still working full time, in Chicago, for a radio company. Still, he used his own money to pay for the expenses of his telescope. It was constructed in Wheaton Illinois, but was later moved to NRAO, Green Bank, West Virginia.

     The telescope was the only radio telescope in the world until after World War II was over. Reber constructed it to be sort of in the shape of a bowl. The mirror in the telescope was 31.4 feet in diameter and made of sheet metal. The mirror focused radio waves to a point about 20 feet above the dish of the telescope. The top part of the telescope, the cylinder, contains the radio receiver. The radio receiver amplifies the cosmic signals in order for them to be recorded on a chart.

    Reber had to design three receivers before he discovered one that worked. The receiver was 160 megahertz, and had a wavelength of 1.9 meters long (4). It was successful in detecting radio emission from the Milky Way. This confirmed the discovery Jansky had made in the 1930s.

     Reber also constructed a new radio telescope in 1951. This telescope was primarily for the mapping of celestial sources of low-frequency long-wave signals. This new telescope was located in Hawaii (3).