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Thread: Underground Antennas

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  1. #1
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    For years I've been coming across stories about underground antennas. Some claim they make good stealth antennas, some say they were used by spies in World War II. Does anybody know if they actually work? I'm not looking to get great performance, but to see if it can be used in a Ham hostile enviroment as a stealth antenna.

    Thanks
    http://forums.qrz.com/group.php?groupid=89 ←The QRZ Railfans group

  2. #2

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    There's one that runs through large portions of Wisconsin and Illinois. It is (or was) used for ELF communications with submarines. Don't really know if it's still in use.
    73, Bob
    SPAR ( [url]http://www.spar-hams.org[/url] ) & ARRL

    You will do what you want. #All the rest is just talk.

  3. #3
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    Smart-alacky answer " Only in caves! ! ! "

    I love it when I can fine a good web page to answer my questions ! Try this one:

    http://www.elfrad.com/

    73, Jim

  4. #4
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    Quote Originally Posted by [b
    Quote[/b] (AG3Y @ Oct. 31 2005,07:47)]I love it when I can fine a good web page to answer my questions ! #Try this one:

    http://www.elfrad.com/

    73, Jim
    That looks interesting.

  5. #5
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    Sounds like Wisconsin's "Project Sanguine".
    Semper ubi sub ubi. 73
    K7KBN CWO4 USNR Ret.

  6. #6
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    First, the Navy's facility at Clam Lake was decomissioned several years ago.
    Second, Don't know about "underground" but when I lived out in West Texas, where the ground conductivity was Really Really bad, I knew an extra class operator who lived in a house with restrictions who would run a long wire out his window along the ground for about 50 feet to the back of his property. Worked lots of DX on this. (with a tuner of course)
    Tom WA4ILH

  7. #7
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    Bet it heats up the worms.

    TOM K8ERV Montrose Colo

  8. #8
    Join Date
    Jan 2000
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    2,956

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    Quote Originally Posted by [b
    Quote[/b] (n2nh @ Oct. 31 2005,06:16)]For years I've been coming across stories about underground antennas. #Some claim they make good stealth antennas, some say they were used by spies in World War II. #Does anybody know if they actually work? #I'm not looking to get great performance, but to see if it can be used in a Ham hostile enviroment as a stealth antenna.

    Thanks
    Stealth it is, great performance it is not.

    Subsurface (underground) antennas have been thought of for about as long as radio has been around. #They received a boost in interest during the "cold war" atomic tensions with the Soviet Union. #It was thought that underground antennas would survive nuclear attack, even if your house did not, so every bomb shelter needed an underground antenna for radio reception or transmission.

    Practical info:
    1 Velocity factor is dielectric dependent, so if you bury an antenna in soil (which is a dielectric) then the physical length will be shorter than the same antenna mounted above ground. #Expect very low velocity factors of 40% to 25%, depending on depth, conditions and soil type, so physical length will be half or less the length of an above ground antenna.

    2. #Soil attenuation will reduce signals substantially. #A dipole buried eight inches below the surface in “normal” soil will have a attenuation of about 16 dB over a 40 meter dipole mounted at 0.3 wavelength above ground. #Attenuation will increase with depth.

    More information may be found in RSGB publication “Practical Wire Antennas” by John Heys, G3BDQ or ARRL “Antenna Compendium Vol 1” article titled “Subsurface Antennas for the Amateur”.

    73,
    Terry, K7FE



    Terry Graves, K7FE
    Chief Editor, QRZ.COM

    "Some people call CW a MODE but in
    reality it is an autonomous LANGUAGE."

  9. #9
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    Quote Originally Posted by [b
    Quote[/b] (K8ERV @ Oct. 31 2005,09:47)]Bet it heats up the worms.

    TOM K8ERV Montrose Colo
    Are you kidding, Do you think that anything can still be alive down there after Texoco and Amoco are through pumping their chemicals into oil depletion wells?

  10. #10

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    Quote Originally Posted by [b
    Quote[/b] (wa4ilh @ Oct. 31 2005,11:11)]
    Quote Originally Posted by [b
    Quote[/b] (K8ERV @ Oct. 31 2005,09:47)]Bet it heats up the worms.

    TOM K8ERV Montrose Colo
    Are you kidding, Do you think that anything can still be alive down there after Texoco and Amoco are through pumping their chemicals into oil depletion wells?
    Ah, marinated worms! Micky D's would be jealous! <GRIN>

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