page_title: Grote Reber
section_title: Medium frequency research
hierarchical_section_title: Grote Reber / Life / Medium frequency research
caption_attribution_description: English: Replica of Grote Reber Radio Telescope at National Radio Astronomy Observatory in Green Bank, West Virginia.
context_page_description: Grote Reber was an American pioneer of radio astronomy, which combined his interests in amateur radio and amateur astronomy. He was instrumental in investigating and extending Karl Jansky's pioneering work, and conducted the first sky survey in the radio frequencies.
  His 1937 radio antenna was the second ever to be used for astronomical purposes and the first parabolic reflecting antenna to be used as a radio telescope. For nearly a decade he was the world's only radio astronomer.
context_section_description: Starting in 1951, he received generous support from the Research Corporation in New York, and moved to Hawaii. In the 1950s, he wanted to return to active studies but much of the field was already filled with very large and expensive instruments. Instead he turned to a field that was being largely ignored, that of medium frequency (hectometre) radio signals in the 0.5–3 MHz range, around the AM broadcast bands. However, signals with frequencies below 30 MHz are reflected by an ionized layer in the Earth's atmosphere called the ionosphere. In 1954, Reber moved to Tasmania, the southernmost state of Australia, where he worked with Bill Ellis at the University of Tasmania. There, on very cold, long, winter nights the ionosphere would, after many hours shielded from the sun's radiation by the bulk of the Earth, 'quieten' and de-ionize, allowing the longer radio waves into his antenna array. Reber described this as being a "fortuitous situation". Tasmania also offered low levels of man-made radio noise, which permitted reception of the faint signals from outer space.
  In the 1960s, he had an array of dipoles set up on the sheep grazing property of Dennistoun, about 7.5 km northeast of the town of Bothwell, Tasmania, where he lived in a house of his own design and construction he decided to build after he purchased a job lot of coach bolts at a local auction. He imported 4x8 douglas fir beams directly from a sawmill in Oregon, and then high technology double glazed window panes, also from the US. The bolts held the house together. The window panes formed a north facing passive solar wall, heating mat black painted, dimpled copper sheets, from which the warmed air rose by convection. The interior walls were lined with reflective rippled aluminium foil. The house was so well thermally insulated that the oven in the kitchen was nearly unusable because the heat from it, unable to escape, would raise the temperature of the room to over 50 °C (120 °F).
caption: Reconstructed Reber Radio Telescope at National Radio Astronomy Observatory in Green Bank, West Virginia
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