File:Trideco.png
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Summary
[edit]DescriptionTrideco.png |
English: Diagram of "Trideco" type VLF antenna. This is a very large wire antenna, often over a mile in diameter, used by powerful transmitters in the very low frequency band. A type of umbrella antenna, it consists of 13 steel radio towers arranged in two concentric circles with a network of cables linking the tops. The cables are arranged in six "panels" extending from the central tower in a hexagonal "snowflake" pattern. The central tower usually serves as the radiating element, acting as a monopole radiator, while the horizontal suspended cables act as a large capacitive top-load, forming a capacitor with the ground, which increases the current in the vertical element, increasing the radiated power. The transmitter power is applied between the bottom of the central tower and a ground connection. VLF antennas require an extremely low resistance ground, so the ground under the antenna is usually covered by a counterpoise, a radial screen of wires suspended a few feet off the ground. A major use of trideco antennas is in powerful Naval transmitters which communicate with submerged submarines. |
Date | |
Source | NAVELEX 0101 113, Fig. 3-7 |
Author | US Navy, Naval Electronics Systems Command |
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[edit]Public domainPublic domainfalsefalse |
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This file is a work of a sailor or employee of the U.S. Navy, taken or made as part of that person's official duties. As a work of the U.S. federal government, it is in the public domain in the United States.
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This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights. |
https://creativecommons.org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse
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[edit]Transferred from en.wikipedia to Commons using For the Common Good.
Date/Time | Dimensions | User | Comment |
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17:30, 1 April 2011 | 916 × 1,196 (100,687 bytes) | w:en:Mcg410 (talk | contribs) | {{Information |Description = Diagram of Trideco type VLF Antenna. |Source = NAVELEX 0101 113, Fig. 3-7 |Date = August 1972 |Author = US Navy, Naval Electronics Systems Command |Permission = |other_versions = }} |
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current | 23:20, 9 July 2014 | ![]() | 916 × 1,196 (98 KB) | Josve05a (talk | contribs) | Transferred from en.wikipedia: see original upload log above |
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