File:Cutler VLF antenna array.png

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Original file (1,449 × 652 pixels, file size: 317 KB, MIME type: image/png)

Captions

Captions

Diagram of a trideco antenna, a large wire antenna used at very low frequencies

Summary

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Description
English: Diagram of one of the two identical antenna arrays at the U.S. Navy Cutler VLF transmitter facility at Cutler, Maine. It transmits operational orders one-way to submerged submarines worldwide at a frequency of 24 kHz with a power of 1.8 megawatts. This type of antenna is called a trideco or umbrella antenna, a form of capacitively top-loaded monopole antenna. It consists of an array of 13 vertical steel masts attached at the top to a system of horizontal cables like an 'umbrella". The cables are divided into 6 "panels" which radiate out from the central tower in a pattern resembling a snowflake. The central mast is 979 ft (298 meters) tall, and the entire array is 6140 ft (1.871 km or 1.16 miles) in diameter. The vertical masts actually radiate the VLF radio waves, while the top cables form a large capacitor with the ground, which serves to increase the efficiency of the antenna. Under each mast there is also a system of cables suspended a few feet above the ground radiating from the mast base, called a Counterpoise (not shown) which functions as the other plate of the capacitor.
Date
Source P. Hansen (September 1994) Technical Report 1681: VLF Cutler Hollow Core Cable Repair/Replacement, Technical Reports and Documents, Space and Naval Warfare Systems Command website, U.S. Navy, p.E-5. The drawing is labelled: Antenna Array Perspective, Naval Communication Unit, Cutler, Maine, Drawing no. 4300164, by Naval Facilities Engineering Command, Atlantic Div., Norfolk
Author Hanson, P.

Licensing

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Public domain
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.
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.

Original upload log

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Transferred from en.wikipedia to Commons using For the Common Good.

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Date/Time Dimensions User Comment
22:45, 16 July 2011 1,449 × 652 (324,272 bytes) w:en:Mcg410 (talk | contribs) ({{Information |Description = Cutler VLF Array |Source = Technical Report 1681 |Date = September, 1994. |Author = Hanson, P. |Permission = |other_versions = }})

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current04:06, 4 January 2013Thumbnail for version as of 04:06, 4 January 20131,449 × 652 (317 KB)Chetvorno (talk | contribs)Transferred from en.wikipedia: see original upload log above

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