File:Early vertical wire antennas.svg
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Summary[edit]
DescriptionEarly vertical wire antennas.svg |
English: Drawing showing types of vertical wire antennas used for the first wireless telegrapy radio transmitters and receivers during the first two decades of the 20th century. Guglielmo Marconi invented the vertical or monopole antenna in 1895, he found he could transmit longer distances by connecting one side of his transmitter to a metal plate suspended above ground and the other side to ground. (A) shows the early type of antenna he used until about 1900. The metal plate, which he called a "capacity area", was to add capacitance to the antenna, since the power output of the early spark gap transmitters was proportional to the amount of electric charge stored in the antenna before each spark. (B) He found that the plate did not help and a simple vertical wire had almost as much capacity. (C-F) Later researchers found that multiple parallel wires were a more convenient way to increase the capacitance, and also decreased the ohmic resistance, improving the efficiency of the antenna. (E) and (F) were called "cage antennas"; the symmetrical geometry equalized the current in the wires, reducing resistance.
Français : Dessin montrant des types d'antennes à fil verticaux utilisées pour les premiers émetteurs et récepteurs radio au cours des deux premières décennies du XXe siècle. Guglielmo Marconi a inventé l'antenne verticale monopole en 1895, il a découvert qu'il pouvait transmettre sur une plus longues distances en connectant un côté de son émetteur à une plaque métallique suspendue au-dessus du sol en extrémité du fils d’antenne.
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Date | |
Source | Own work |
Author | Chetvorno |
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This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. | |
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse |
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Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 23:55, 10 December 2018 | 1,627 × 951 (70 KB) | Chetvorno (talk | contribs) | Altered shape of metal plate in first (A) antenna to make it look more like pictures of Marconi's antennas | |
18:07, 12 February 2018 | 1,627 × 951 (80 KB) | Chetvorno (talk | contribs) | User created page with UploadWizard |
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Width | 459.07251mm |
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Height | 268.36197mm |