File:Marconi first monopole transmitter 1896.png
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Summary
DescriptionMarconi first monopole transmitter 1896.png |
English: The first spark gap radio transmitter with a monopole antenna invented by radio pioneer Guglielmo Marconi in 1895 and patented 1896 (US patent 586193, G. Marconi, Transmitting electrical signals, filed 7 December 1896, granted 13 July 1897) during his development of the first radiotelegraphy communication system. It is a modification of Heinrich Hertz's dipole transmitter to give greater range. The invention of the monopole antenna was the breakthrough that enabled Marconi to transmit long distances, making radio practical. The short horizontal dipole antennas Marconi had been using, invented by Heinrich Hertz, generated radio waves in the very high frequency range which were limited to line of sight propagation. Marconi replaced one side of the dipole with a connection to ground and the other side with a metal plate "capacity area" suspended high above the ground. The lower frequency vertically polarized waves which this antenna produced propagated as ground waves which followed the contour of the Earth, so they could travel beyond the visual horizon. The four balls are called a Righi spark gap, invented by Marconi's mentor Augusto Righi, which was designed to reduce the energy lost in the spark. |
Date | |
Source | Retrieved 28 January 2018 from Charles Grinnell Ashley, Charles Brian Hayward (1912) Wireless Telegraphy and Wireless Telephony: An understandable presentation of the science of wireless transmission of intelligence, American School of Correspondence, Chicago, IL, p. 31, fig. 15 on Google Books |
Author | Charles Grinnell Ashley and Charles Brian Hayward |
Licensing
Public domainPublic domainfalsefalse |
This work is in the public domain in the United States because it was published (or registered with the U.S. Copyright Office) before January 1, 1929.
Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country.
Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Marconi_first_monopole_transmitter_1896.png |
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Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 00:22, 10 February 2018 | 540 × 798 (42 KB) | Chetvorno | User created page with UploadWizard |
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Horizontal resolution | 28.35 dpc |
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Vertical resolution | 28.35 dpc |
File change date and time | 19:36, 28 January 2018 |