tree as antenna

[Allan Adler]

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.

 

[Art]

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??

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.
--
Ignorantly,
Allan Adler <[email protected]>
* Disclaimer: I am a guest and *not* a member of the MIT CSAIL. My actions and
* comments do not reflect in any way on MIT. Also, I am nowhere near

Boston.

 

[CWatters]

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.

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

 

[CWatters]

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.

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

 

[Pat Deegan]

I haven't look to see who wrote this article (or the quality of the science
behind the statements it contains)

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,

 

[Allan Adler]

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?

 

[L.]

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.

 

[wwaaves]

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 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.

 

[Roger Gt]

: > 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.

 

[NO SPAM]

: > 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

 

[Roger Gt]

:
: : >
: > : > : > : > 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.