Size of this preview: 536 × 600 pixels. Other resolutions: 214 × 240 pixels | 429 × 480 pixels | 991 × 1,109 pixels.
Original file (991 × 1,109 pixels, file size: 129 KB, MIME type: image/png)
 | This is a file from the Wikimedia Commons. Information from its description page there is shown below. Commons is a freely licensed media file repository. You can help. |
Summary
| Description |
Diagram of the antenna array at the U.S. Navy Cutler VLF transmitter facility at Cutler, Maine. It transmits operational orders one-way to submerged U.S. submarines worldwide at a frequency of 24 kHz. With a transmitter power of 1.8 megawatts, it is known as the most powerful radio transmitter in the world. It consists of two identical antenna arrays called the 'North array' and 'South array', driven from a transmitter building between them. This type of antenna is called a trideco or umbrella antenna, a form of capacitively top-loaded electrically-short monopole antenna. Each array consists of a hexagonal pattern of 13 vertical steel masts attached at the top to a system of 6 diamond-shaped fans of cables suspended above the ground. 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. Each central mast is 304 m (997.5 ft) high, and has a 'helix house' at its base, which contains massive coils of wire needed to match the antenna to the transmission line, which travels through an underground tunnel from the transmitter. |
| Date | |
| Source | P. Hansen (September 1994) Technical Report 1681: VLF Cutler Hollow Core Cable Repair/Replacement, Technical Reports and Documents, US Navy Space and Naval Warfare Systems Command website, p.3, fig.1. Originally from NAVELEX 0101, 113: Naval Shore Electronics Criteria: VLF, LF, and MF Communication Systems, FSN 0280-901-1000, Naval Electronic Systems Command, Dept. of the Navy, August 1972, p. 3-16, Fig. 3-10 on Nick Englund's US Navy Radio Communications website. |
| Author | US Navy, Naval Electronics Systems Command |
Licensing
|
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
Transferred from en.wikipedia to Commons using For the Common Good.
The original description page was here. All following user names refer to en.wikipedia.
| Date/Time | Dimensions | User | Comment |
|---|---|---|---|
| 17:11, 1 April 2011 | 991 × 1,109 (132,044 bytes) | w:en:Mcg410 (talk | contribs) | ({{Information |Description = Cutler, Maine Antenna Installation |Source = Fig 3-10, page 3-16, of NAVELEX 0101, 113 |Date = August 1972 |Author = US Navy, Naval Electronics Systems Command |Permission = |other_versi) |
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 06:08, 4 January 2013 | | 991 × 1,109 (129 KB) | Chetvorno | Transferred from en.wikipedia: see original upload log above |
File usage
The following pages on the English Wikipedia use this file (pages on other projects are not listed):
Global file usage
The following other wikis use this file:
- Usage on de.wikipedia.org
- Usage on fr.wikipedia.org
