USN ELF Communications System
Michigan - Republic ELF transmitter site - photos,
Wisconsin - Clam Lake ELF transmitter site - info
1987 Popular Science Magazine
article on ELF system and other sub comms
1988 Popular Communications Magazine article
Briefing - "ELF Communication Concepts and Capabilities" - 6
Briefing - "ELF Communications System" - 4
Briefing - "ELF Communications System" - 3
Info sheet - "Information about ELF Communications" - 0.4
Early ELF tests -
There were two feasibility tests in the 1960's. Many thanks to Don Utt
for info, pointers, and corrections.
- Tests in Wyoming used a 70 km long stretch of HV power line that was
disconnected at night.
- Tests in NC/VA (Test Site Alpha) conducted by RCA Laboratories as part of
Project Pangloss used a 176 km long line constructed from Lookout Shoals NC
to Algoma VA. The line resembled a 3-phase power line with the 4/0
(0.46" dia.) lines hooked
together and grounded at the ends. The transmitter (10kw or 120kw vibration table
amp) was initially housed in a
mobile van and later in a building (Ararat NC?).
- The North ground system consisted of a 2000 sq. ft. mesh with ground rods.
The South ground system consisted of nine 1200 ft. radials in the lake. source.
Another article says the early tests had ground radials several kilometers
long at each end.
- Another source
says "The concept of a horizontal grounded wire was tested in 1962 by
the DECO company with a leased power line 70 kilometres long [in Wyoming]
and, in 1963,
during the "intensive test" phase, with a purpose-built wire
aerial running 176 kilometres between West Virginia [sic] and North
Carolina. The current in the antenna was 60 amps and various ELF frequencies
between 4 Hz and 500 Hz were radiated. Accurate data of atmospheric
attenuation were obtained and, for the first time, the submarine USS Seawolf
detected ELF signals 3200 kilometres away in the North Atlantic. This was in
early 1963 [April?] at a radiated power of one watt." This info
was probably taken from this article.
- A 1963
Polaris project report says "Once set up, we ran something that
could be regarded as a decisive experiment and figure
30 indicates the results at 520 miles with the submarine moving at 6
knots at a 150-foot depth. Again, we received a 156-cycle
signal at 2500 miles with the submarine moving at 18 knots at a
- Another source
says "Extremely low frequency (ELF) electromagnetic wave propagation
was investigated by measuring the amplitude of a CW signal transmitted from
the Sanguine site in North Carolina to receiving sites located in New York
State, Labrador, and Iceland. The attenuation factor α and the
reciprocal of the excitation factor were determined. Data for daytime,
nighttime, and sunrise transition paths were obtained. The attenuation
factors obtained for 78 and 156 Hz are compared with the value of α
obtained from measurements of atmospherics. The attenuation values at 78 Hz
of 1.29 and 1.01 dB/1000 km, and a value of 0.75 dB/1000 km at 45 Hz,
obtained by interpolation of results of this and other experiments, were
used in Sanguine systems analysis."
- A 1981
New York Times story refers to the following article - if you can
provide a copy I'd really appreciate it.
- Roland J. Starkey, Jr., "The Renaissance in Submarine
Communications, Part III, The ELF Odyssey 1958-1979,"
January 1981, p. 26.
- A report I'd like to find is C. A. Martin, "Site Evaluation for a
Beverage Type Transmitting Antenna", PANGLOSS Task 4 Technical Note 6,
RCA Laboratories, Princeton, NJ, 1964.
- Another report I'd like to find is the "Propagation Measurements
Along a 4900 km Path", Project Sanguine Special Topics Report 11, RCA
Labs, Princeton NJ, 1967. - This article
probably has the same info.
- If you have any technical or other info on these early tests, please let
Clam Lake WI - Naval Electronic Engineering Office