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tree as antenna

Discussion in 'Misc Electronics' started by Allan Adler, Aug 23, 2004.

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  1. Allan Adler

    Allan Adler Guest

    Since it has been remarked in another thread that wood is a conductor,
    and since trees are as big as radio wavelengths, I'm wondering if there
    is any convenient way to measure how much electromagnetic radiation a
    particular tree is picking up at a particular radio frequency.

    What started me wondering about this is not the desire to use trees
    to pick up radio stations or to use forests for antenna arrays for
    radio astronomy (although the thought did cross my mind), but an
    article in a recent issue of Natural History about the visual systems
    of plants. The article maintains that plants have sophisticated systems
    that allow them to figure out how many other plants are around them,
    even if they are not shaded by them, and to figure out when to flower,
    among other things. The article is concerned with visible light and
    infrared and discusses mechanisms at the molecular level that respond
    to such light. I don't expect that plants have responses to radio waves
    at the molecular level, for reasons of resolution (not that I really
    know), but it did seem natural to wonder whether plants might have
    some kind of response to radio waves when the plants are large enough
    to serve as antennas at those frequencies.
     
  2. Art

    Art Guest

    Multi Wave Vertical with multiple stingers, Eh!! Just think how much power
    you could pump into a 50' Oak before you blew the finals on the old CB.Eh??
    Boston.
     
  3. CWatters

    CWatters Guest

    In some farmed forrests trees are planted at regular intervals - might have
    more of an effect?
     
  4. CWatters

    CWatters Guest

    I haven't look to see who wrote this article (or the quality of the science
    behind the statements it contains) but you might find it interesting towards
    the middle/bottom of the page.

    http://www.leyman.demon.co.uk/08_Microwaves.html
     
  5. Pat Deegan

    Pat Deegan Guest

    I can't say that I've delved deeply into this site, but it gets pretty
    fishy around chapter 11

    http://www.leyman.demon.co.uk/11 Earth Stress, Earthquakes, amd Earth Sensitives SAH11.html

    "The reader will now need to put the desire for proof on hold. Trust has
    to become a major element", etc.


    However the referenced Wolfgang Volkrodt paper is available...
    have a look at the links at the bottom of the
    http://www.emrpolicy.org/science/forum/
    page. The "Electromagnetic Pollution of the Environment" document seems to
    conclude that otherwise clean forests (in Germany, Canada...) are being
    adversly affected by military radar installations and radio links.

    It's more a presentation for conference more than a scientific
    paper but may give you some more leads.

    HTH.

    Regards,
     
  6. Allan Adler

    Allan Adler Guest

    Thanks for the suggestions on how radio waves might affect trees, but
    that wasn't really the point of my posting, only my original motivation.
    The point was to find out how to measure how much electromagnetic radiation a
    particular tree is picking up at a particular radio frequency.

    For example, do you drive a nail into the tree and connect the nail via
    a wire to your pocket radio? Or do you use a dish to first measure how
    much radiation of that frequency there is in some other direction with
    no obstacles in it, then see how much comes from the direction of the
    tree, compute how much of the latter is due to reflection off the tree
    and then subtract from the first measurement to estimate how much is
    being absorbed?
     
  7. L.

    L. Guest

    I knew a man once who claimed to have had either a CB or Ham radio antenna
    as a part of a tree. He claimed it worked and others also backed him. I
    never witnessed it myself, so I can't say for sure. I'm trying to recall HOW
    he did it. It had something to do with spikes or nails and perhaps (not
    sure) use them as a beam array of sorts with a vertical radiation.. I say
    beam in that when you have a beam, you have a reflector, the driven element
    and then the directors. I do believe that was his set up in the tree.

    L.
     
  8. wwaaves

    wwaaves Guest

    A professor of mine once told me of his friend in a ham radio club who
    used a tree as the antenna for a transciever during a field hunt.
    After searching for the target for hours he finally told the group
    that he worked on research during WWII using trees as antennas. Sounds
    like the military has been doing this for years.
     
  9. Roger Gt

    Roger Gt Guest

    : > I knew a man once who claimed to have had either a CB or Ham
    radio antenna
    : > as a part of a tree. He claimed it worked and others also
    backed him. I
    : > never witnessed it myself, so I can't say for sure. I'm trying
    to recall HOW
    : > he did it. It had something to do with spikes or nails and
    perhaps (not
    : > sure) use them as a beam array of sorts with a vertical
    radiation.. I say
    : > beam in that when you have a beam, you have a reflector, the
    driven element
    : > and then the directors. I do believe that was his set up in
    the tree.
    : >
    : > L.
    :
    : A professor of mine once told me of his friend in a ham radio
    club who
    : used a tree as the antenna for a transceiver during a field
    hunt.
    : After searching for the target for hours he finally told the
    group
    : that he worked on research during WWII using trees as antennas.
    Sounds
    : like the military has been doing this for years.

    Well, mostly in WW2.
    It has been dome many times in field installations where hiding
    was necessary.
     
  10. NO SPAM

    NO SPAM Guest

    I say, whatever it takes... If it works, DO IT! ANYTHING is better than
    nothing when you're in a bind. Who knows, maybe someone will live in a place
    where no "antennas" are allowed, not to mention towers, mast, etc. IF there
    is a tree there, they could use it and no one be the wiser. Maybe it won't
    work as well as a commercial job, but if you want to be on the air, then the
    tree beats nothing (at least speaking outdoors). There are 2 meter antennas
    which have been on the market for a while to be "stealth" antennas for areas
    which don't like antennas. Ya got to do what ya got to do.

    NS
     
  11. Roger Gt

    Roger Gt Guest

    :
    : : >
    : > : > : > : > I knew a man once who claimed to have had either a CB or
    Ham
    : > radio antenna
    : > : > as a part of a tree. He claimed it worked and others also
    : > backed him. I
    : > : > never witnessed it myself, so I can't say for sure. I'm
    trying
    : > to recall HOW
    : > : > he did it. It had something to do with spikes or nails and
    : > perhaps (not
    : > : > sure) use them as a beam array of sorts with a vertical
    : > radiation.. I say
    : > : > beam in that when you have a beam, you have a reflector,
    the
    : > driven element
    : > : > and then the directors. I do believe that was his set up
    in
    : > the tree.
    : > : >
    : > : > L.
    : > :
    : > : A professor of mine once told me of his friend in a ham
    radio
    : > club who
    : > : used a tree as the antenna for a transceiver during a field
    : > hunt.
    : > : After searching for the target for hours he finally told the
    : > group
    : > : that he worked on research during WWII using trees as
    antennas.
    : > Sounds
    : > : like the military has been doing this for years.
    : >
    : > Well, mostly in WW2.
    : > It has been dome many times in field installations where
    hiding
    : > was necessary.
    : >
    : >
    :
    : I say, whatever it takes... If it works, DO IT! ANYTHING is
    better than
    : nothing when you're in a bind. Who knows, maybe someone will
    live in a place
    : where no "antennas" are allowed, not to mention towers, mast,
    etc. IF there
    : is a tree there, they could use it and no one be the wiser.
    Maybe it won't
    : work as well as a commercial job, but if you want to be on the
    air, then the
    : tree beats nothing (at least speaking outdoors). There are 2
    meter antennas
    : which have been on the market for a while to be "stealth"
    antennas for areas
    : which don't like antennas. Ya got to do what ya got to do.
    :
    : NS
    :
    Gutters work too! As will a wire run under the eves. I have even
    run a single strand of wire up a tree and used it as an antenna,
    the tree loads the wire so tuning was dicey. I have also used
    aluminum foil in the attic. Works fine too.

    An antenna hidden inside a vent extension will sometimes go for
    years before someone notices. I have also see a mobile antenna
    on a the back of a trellis in the rear garden. Buried the feed
    line.
     
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