[CW] NAA Cutler Maine USN VLF 1.8 Megawatt Station

Sun Nov 29 22:25:26 EST 2020

  NCTAMSLANT - Naval Computer and Telecommunications Area Master Station
Atlantic, Cutler, Maine. 2.8 megawatts on 24 kHz.

https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler
The *VLF Transmitter Cutler* is the United States Navy
<https://en.wikipedia.org/wiki/United_States_Navy>'s very low frequency
<https://en.wikipedia.org/wiki/Very_low_frequency> (VLF) shore radio
station at Cutler, Maine <https://en.wikipedia.org/wiki/Cutler,_Maine>. The
station provides one-way communication to submarines
<https://en.wikipedia.org/wiki/Communication_with_submarines> in the Navy's
Atlantic Fleet, both on the surface and submerged. It transmits with call
sign <https://en.wikipedia.org/wiki/Call_sign> NAA, at a frequency of
24 kHz and input power of up to 1.8 megawatts, and is one of the most
powerful radio transmitters in the world.[*citation needed
<https://en.wikipedia.org/wiki/Wikipedia:Citation_needed>*]
Contents

   - 1Establishment at Cutler, Maine
   <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#Establishment_at_Cutler,_Maine>
   - 2Antenna <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#Antenna>
   - 3Antenna maintenance
   <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#Antenna_maintenance>
   - 4See also
   <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#See_also>
   - 5References
   <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#References>
   - 6Further reading
   <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#Further_reading>

Establishment at Cutler, Maine[edit
<https://en.wikipedia.org/w/index.php?title=VLF_Transmitter_Cutler&action=edit&section=1>
]

The current Cutler Naval Station was built in 1960 and became operational
on January 4, 1961. It has a transmission power of 2 megawatts. As with all
VLF stations, the transmitter has a very small bandwidth
<https://en.wikipedia.org/wiki/Bandwidth_(signal_processing)>, and so
cannot transmit audio (speech) but only coded text messages, at a
relatively low data rate <https://en.wikipedia.org/wiki/Baud_rate>. The
transmission consists of a continuously encrypted minimum-shift keying
<https://en.wikipedia.org/wiki/Minimum-shift_keying> (MSK) signal capable
of multi channel operations.[1]
<https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#cite_note-1> The
transmitter operates on 24.0 kHz. In the past it operated on 17.8 kHz. The
callsign of the station is *NAA*.
Antenna[edit
<https://en.wikipedia.org/w/index.php?title=VLF_Transmitter_Cutler&action=edit&section=2>
]
<https://en.wikipedia.org/wiki/File:Cutler_VLF_antenna_array_site_plan.png>
<https://en.wikipedia.org/wiki/File:Cutler_VLF_antenna_array_site_plan.png>
Diagram of Cutler antenna array
<https://en.wikipedia.org/wiki/File:Cutler_VLF_antenna_array.png>
<https://en.wikipedia.org/wiki/File:Cutler_VLF_antenna_array.png>
Isometric drawing of one of the two antenna arrays

The extensive antenna system consists of two separate identical umbrella
antenna <https://en.wikipedia.org/wiki/Umbrella_antenna> arrays, designated
the “north array” and the “south array”. Each array consists of a ring of
13 tall metal masts <https://en.wikipedia.org/wiki/Radio_mast> connected at
the top by a network of horizontal cables. The cables form six
diamond-shaped "panels" radiating from the central tower in a hexagonal
pattern shaped like a snowflake. The two arrays normally operate together
as one antenna, but each is designed to function independently to allow
maintenance on the other array. The central tower of each antenna system is
304 m (997.4 ft) tall. It is surrounded by six 266.7 m (875 ft) tall masts,
placed on a ring with a radius of 556 m around the central tower. The
remaining six towers of the array are 243.5 m (799 ft) tall, placed on a
circle of 935.7 m (3070 ft) around the central tower.[2]
<https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#cite_note-2>

Each element (“panel”) of the antenna is suspended between the central
tower, two towers of the inner ring and one tower of the outer ring. The
entire array is 6140 ft (1.871 km or 1.16 miles) in diameter.

This type of antenna array is called a trideco or umbrella antenna
<https://en.wikipedia.org/wiki/Umbrella_antenna>, a type of antenna which
can radiate power efficiently at the low 24 kHz frequency used. It
functions as a capacitively <https://en.wikipedia.org/wiki/Capacitor>
 top-loaded electrically short
<https://en.wikipedia.org/wiki/Electrical_length> monopole antenna
<https://en.wikipedia.org/wiki/Monopole_antenna>. Vertical wires at the
central mast of the antenna radiate the VLF radio waves, while the
suspended horizontal cable array functions as a large capacitor
<https://en.wikipedia.org/wiki/Capacitor>, increasing the efficiency of the
vertical radiators. At the base of each mast is a star-shaped network of
cables suspended a few feet above the ground, extending out hundreds of
feet, called a *counterpoise
<https://en.wikipedia.org/wiki/Counterpoise_(ground_system)>*, which serves
as the bottom plate of the "capacitor".

The climate in Maine results in severe icing of the antenna wires during
the winter, resulting in unacceptably large loads on the supporting
structures. Therefore, the antennas have a deicing system which runs large
60 Hz electric currents through the wires, heating them, to melt the ice.
The power required for deicing is 3 MW, higher than the transmitter output
power. An antenna array cannot transmit while it is being deiced, and one
reason for having two arrays was to allow one array to be deiced while the
other provides crucial uninterrupted transmission capability. Repairs and
adjustments to an array can also be made without interrupting transmission.
Antenna maintenance[edit
<https://en.wikipedia.org/w/index.php?title=VLF_Transmitter_Cutler&action=edit&section=3>
]

Antenna maintenance is performed during the summer months. During
maintenance periods the station transmits on one array while work is
performed on the other array, which is grounded. This allows continuous
transmission, crucial since the Navy closed Annapolis
<https://en.wikipedia.org/wiki/NSS_Annapolis> (NSS), the only other East
Coast <https://en.wikipedia.org/wiki/East_Coast_of_the_United_States> VLF
station.

The region where the two arrays come close together, near the transmitter
house, is called the "bow-tie area". There are two panels and three towers
from each array in this area. The fields on the grounded array are highest
in the bow-tie area due to proximity to the active array. The present
station operating procedure, based on a past RADHAZ
<https://en.wikipedia.org/wiki/Electromagnetic_radiation_and_health> survey,
does not allow work on the bow-tie area towers or panels while transmitting
on the other array. There is an ongoing tower painting project at Cutler
scheduled for completion over the next few years. Under the present station
policy, completion of this project would require several months of total
downtime.

Test transmissions have been arranged, during which, only four panels of
one array are connected to the transmitter. The objective of the four-panel
tests was to allow painting and normal maintenance on the bow-tie area
towers of the inactive array. A secondary objective of the tests is to
characterize the antenna operating parameters which had not been measured
since changing to 24.0 kHz.
See also[edit
<https://en.wikipedia.org/w/index.php?title=VLF_Transmitter_Cutler&action=edit&section=4>
]

   - Jim Creek Naval Radio Station
   <https://en.wikipedia.org/wiki/Jim_Creek_Naval_Radio_Station>
   - Naval Communication Station Harold E. Holt
   <https://en.wikipedia.org/wiki/Naval_Communication_Station_Harold_E._Holt>
   - Lualualei VLF transmitter
   <https://en.wikipedia.org/wiki/Lualualei_VLF_transmitter>
   - Aguada transmission station
   <https://en.wikipedia.org/wiki/Aguada_transmission_station>
   - List of masts <https://en.wikipedia.org/wiki/List_of_masts>

References[edit
<https://en.wikipedia.org/w/index.php?title=VLF_Transmitter_Cutler&action=edit&section=5>
]
[image: naa_badge.jpg]

   1. *^ <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#cite_ref-1>*
Marten,
   M. (2007). *Spezial-Frequenzliste 2007-2008, Band 2* (in German) (17th
   ed.). Meckenheim, Germany: Siebel Verlag. p. 36. ISBN
   <https://en.wikipedia.org/wiki/ISBN_(identifier)> 978-3-88180-665-7
   <https://en.wikipedia.org/wiki/Special:BookSources/978-3-88180-665-7>.
   2. *^ <https://en.wikipedia.org/wiki/VLF_Transmitter_Cutler#cite_ref-2>*
Klawitter,
   G.; Herold, K.; Oexner, M. (2000). *Langwellen- und Laengstwellenfunk* (in
   German). Meckenheim, Germany: Siebel Verlag. pp. 82–83. ISBN
   <https://en.wikipedia.org/wiki/ISBN_(identifier)> 3-89632-043-2
   <https://en.wikipedia.org/wiki/Special:BookSources/3-89632-043-2>.

Further reading[edit
<https://en.wikipedia.org/w/index.php?title=VLF_Transmitter_Cutler&action=edit&section=6>
]

   - "NCTCS, Cutler Maine; NCTAMS LANT DET, Cutler East Machias, Maine"
   <http://www.globalsecurity.org/military/facility/cutler.htm>.
   GlobalSecurity.org. Retrieved 6 February 2008.
   - A Lockportian Goes "Down East" In Maine (includes photos of NAA towers)
   <http://www.lockport-ny.com/atlarge3.htm>
   - Hansen, P. (September 1994). "VLF Cutler Hollow Core Cable
   Repair/Replacement (Technical Report 1681)"
   <http://www.spawar.navy.mil/sti/publications/pubs/tr/1681/tr1681.pdf>
   (PDF). Retrieved 22 June 2017.
   - http://cryptome.org/eyeball/cutler/cutler-eyeball.htm
   - http://www.lockport-ny.com/QCWA/activities.htm
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