Radio transmitting through the ground

[stanger]

OK, I know that radio waves don't really work well in the ground, but it is the best analogy I could think of for this question.

Back in the mid 1960's, I remember reading an article in Popular Electronics, or similar magazine, about building a device that allowed people to communicate through a device that transmitted through the ground. It worked basically like a radio, but used a ground pole instead of an antenna. I remember that the range on it was at least a mile or two and that it worked better when the earth was wet, like a day or two after a good rain. This was a setup that they showed how to build and was simple enough for home construction.

I have never seen nor heard of such a setup since.
Has anyone heard of this, know what it is called and have any information about it?

[rfgdxm]

http://www.borderlands.com/newstuff/...round-myst.htm
http://www.fnal.gov/pub/inquiring/questions/elf.html
http://homepage.ntlworld.com/lapthorn/elf.htm

If you want to know more, search using "extremely low frequency". It's possible if the frequency is low enough.

[Stan Doubt]

It works great, but whales tend to swim off course and smash into your house.

[Squink]

Extremely Low Frequency Transmitter Site: Clam Lake, Wisconsin

Shut down

September 20th, 2004
The U.S. Navy has announced that it will shut down the controversial Extremely Low Frequency (ELF) Communications System on September 30, ending operations at the Two ELF transmitter facilities located near Clam Lake and Michigan's Escanaba State Forest.
The announcement came Friday afternoon in a news release from the Public Affairs Office of the U.S. Fleet Forces Command in Norfolk, Va.
"The Navy used the ELF system to maintain secure communications with submarines at sea. Improvements in the communications technology and the changing requirements of Today's Navy made the ELF communications system no longer necessary," said the news release.

I toured the Clam Lake site in 72. The lake had more leeches than clams.

[rfgdxm]

http://www.luminet.net/~wenonah/history/nathan-s.htm

From what stranger wrote, I'm not sure exactly what it is. Nor have I ever looked into this Stubblefield ground radio system in detail, or exactly how it works. My best guess is that stranger read some article in the 1960s about transmitting ELF of VLF radio signals through the ground. Producing such low frequency radio signals is quite trivial for amateurs with little technical knowledge. As would be transmitting them into the ground. Not much practical use in amateur terms, as one can trivially get much better distance using an antenna. However, I can see some people doing it for the "gee whiz" novelty aspect.

For those curious about the possibilities of amateurs transmitting radio signals over the air in the Very Low Frequency band, search "lowfer" on Google. Radio enthusiasts using 1 watt transmitters, and transmititing antennas just 50 feet long (the max allowed in the US by the FCC), routinely communicate with each other hundreds of miles away.

[engineer_comp_geek]

I'm told that ELF signals bounce through the polar ice rather nicely. I believe the navy used to take advantage of this during the cold war era to allow their subs to communicate all through the arctic region. The bandwidth was pretty limited, but unlike on land, the signals travelled for very long distances through the ice.