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SublimeMudTime t1_iu60j26 wrote

I thought a long time ago I read that there was an ELF (extremely low frequency) transmitter in Black Duck, MN.

44

KMjolnir t1_iu622cs wrote

Surface vessels would be easier to reach and wouldn't need something that big. Water blocks a lot, and any large surface installation that could reach a sub would be gone. Reaching a nuckear-armed sub, from underground, would require something massive.

17

reddit455 t1_iu63bby wrote

there's STILL one in Colorado (and a few other places around the world).. it literally takes a minute or so just to transmit time. few bytes

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https://www.nist.gov/pml/time-and-frequency-division/time-distribution/radio-station-wwvb/help-wwvb-radio-controlled

In the United States, the signals received by radio controlled clocks originate from NIST Radio Station WWVB, which is located near Fort Collins, Colorado. WWVB broadcasts on a frequency of 60 kHz. Your radio controlled clock actually has a miniature radio receiver inside, which is permanently tuned to receive the 60 kHz signal.

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TacTurtle t1_iu6bn25 wrote

It is actually more that the wavelength for extremely low frequency radio requires extremely long antennas for efficient transmission and reception - not an electrical hardware size issue.

Wavelength = speed of light / frequency so as frequency goes down, wavelength (and antenna size) go up.

Subs use a long antenna cable they can extend and tow behind underwater for ULF radio transmission and reception.

Faster transmission with a shorter antenna requires getting closer to the surface for higher freq radio which will not penetrate water as easily.

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TacTurtle t1_iu6fhd4 wrote

The actual generation and radio equipment could fit in a couple shipping containers or a small building, it is the antenna that is big.

3MW is small enough power you can get them as pre-packaged skid-mounted units like https://www.westernstatescat.com/power-systems/electric-power/gas-generator-sets/cg260-12-2100kw-3000kw3mw-gas-generator-2/

Example: check out this weather radar array - radar is radio broadcast and receive, just at much higher frequency. WSR-88D weather radars for reference are almost 1MW. The Wisconsin ELF was 2.6Mw.

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Wurm42 t1_iu6obqj wrote

The extremely-low frequency (ELF) array the Navy eventually built could be used to reach surface ships or land forces as well, but there were easier, more effective ways to communicate with everything but submarines.

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Wurm42 t1_iu6p7wf wrote

Yeah, the bitrate is terrible, which is why Sanguine and other early military ELF transmitters only sent three-letter code groups.

The messages you could send were basically "Sub X, execute plan Q out of your standing orders, or "Sub X, find a safe spot to surface and check in by radio or satellite coms".

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DanYHKim t1_iu7a5xl wrote

Was this used in Red October?

1

pickleer t1_iu7qil2 wrote

Nicola? Nicola Tesla, is that you I hear??

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cain071546 t1_iu87ci6 wrote

It's Nuclear, Nuculear is not a word. >Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as Voyager 2. Generating electricity from fusion power remains the focus of international research.

https://en.wikipedia.org/wiki/Nuclear_power

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Njt8i945_4 t1_iu8a8v3 wrote

Exterminly Low Frequency Radio System.

1

SSF2T t1_iu8ldge wrote

Still not the dumbest thing your governments have done by far

−4

Gene_Different t1_iu8w481 wrote

Jim Creek, Cutler, Lualualei, O-Sub, N-Sub, etc. etc...

1