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ELF Antenna Puzzle

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Proud Mary

Fri Apr 17 2009, 05:18PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Years ago, during the Cold War, I recall hearing of an outlandish (abandoned) plan to turn an entire Scottish island into an ELF antenna for communicating with submarines.

I know only that the transmitter output was to be coupled into the sea, but I have often wondered how this was to be configured. Clearly, the granite island itself was to be considered to be non-conductive dielectric, so would it have been configured as a tuned slot - the island itself representing the slot - or might it have been set up as a magnetic loop antenna? I suppose, given the scale of the undertaking, that the electrodes could have been placed quite close together, as in a conventional loop, but separated by a long dielectric wall stretching miles out to sea.
Or could the exciting electrodes simply have been placed on equipotential opposite sides of the island.

Any ideas, anyone?

Chris Russell

Sat Apr 18 2009, 03:09AM

... not Russel!
Registered Member #1 Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052

I'd guess it would be similar to the setup that ZEVS uses (used?), as shown here:

Basically, you build your station somewhere with poor ground conductivity, then run the signal to two enormously deep grounds. Seems like the idea is more to just force the signal through the earth than to actually radiate anything.

Proud Mary

Sat Apr 18 2009, 08:28PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Chris Russell wrote ...

I'd guess it would be similar to the setup that ZEVS uses (used?), as shown here:

Thanks for that, Chris. The vast scale of these 'antenna' systems seems to put them in the 'national effort' class.

Bored Chemist

Sat Apr 18 2009, 08:39PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

A similar system is described here.

Steve Conner

Sat Apr 18 2009, 08:42PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Amazing! These articles should also be of interest to the Tesla wireless power freaks, they can see how hard it really is to charge the entire planet.

Standard antenna theory goes out of the window when you're trying to transmit signals through conducting media like earth and salt water.

Proud Mary

Sun Apr 19 2009, 02:07AM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

This one struck me as being very interesting:

Unknown ELF-Signals and Ground Currents
by Kurt Diedrich, Germany

On this web page, the author tells about his experiences in receiving ELF waves in a frequency range between zero and approximately 25 Hz. Normally, this range should be completely free of signals, except those from the 16 Hz railway supply, the Schumann Resonance and a few natural signals, caused by solar activities. But to the author's surprise, a number of obviously artificial signals seem to be sent out by some unknown sources permanently, created by electric currents flowing through the surface of the ground and only visible and hearable by using a sound card as a kind of "time microscope".

blammo

Wed Jul 15 2009, 01:45AM

Registered Member #2212 Joined: Fri Jul 10 2009, 06:12AM
Location:
Posts: 3

Several months ago I did some experiments with VLF reception. My antenna was 500 feet of wire wrapped around a PVC frame. Here's a link to a (very) large picture:

The antenna was connected directly to a USB sound card and I used software to 'tune' it by filtering out the frequencies I didn't want to hear. I made a spooky recording which might correspond to the first set of signals discussed on that web page.

Please beware, there is a loud buzz at the end of the mp3:

After I made the recording, I moved the antenna around and discovered that there was a 'reply' in the blank portions of the recording - an identical sounding signal coming from a different direction (my loop antenna was bidirectional).

Chris Russell

Wed Jul 15 2009, 06:00AM

... not Russel!
Registered Member #1 Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052

Has the recording been sped up or slowed down, or shifted in frequency? The signal looks and sounds pretty much identical to a laptop's trackpad, but I generally detect them around 30-40kHz, depending on the laptop, not down in the 3kHz range. The usage also seems similar to a trackpad in use. Possibly picking up your own trackpad, or a neighbor's?

blammo

Wed Jul 15 2009, 06:51AM

Registered Member #2212 Joined: Fri Jul 10 2009, 06:12AM
Location:
Posts: 3

The laptop was closed while the recording was being made, and everything else in the house was turned off. I don't think I was picking up my own trackpad because as I said I was able to find a 'reply' signal in the empty spaces once I turned the antenna.

The audio was cleaned up a bit (background noise removed) but the pitch was not shifted and that was the original speed. The recording was made at night in my basement in a suburban area, so it's very unlikely it was someone else's computer.

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