using trees as antenna
 

Some years ago, there was an article in QST about using trees as
antenna. There was a sort of toroidal winding in the air, the tree
beeing in the center. If I remember well, the article reported
experiences in the army.

Do you remember ? Can you give me more information ?

Thanks a lot !

using trees as antenna
 

On 26 Sep 2006 01:30:44 -0700, "
wrote:

Some years ago, there was an article in QST about using trees as
antenna. There was a sort of toroidal winding in the air, the tree
beeing in the center. If I remember well, the article reported
experiences in the army.

Do you remember ? Can you give me more information ?

Thanks a lot !

Hi OM,

There was some discussion of this in this group about 8 - 10 years
ago. Most thought it was absurd. Some thought it was possible. None
considered it very effective. One reported experience (and he was
thoroughly mocked). The tree was treated as a vertical radiator, and
was fed against ground and into a nail to penetrate to the conductive
fiber. Some form of matching was generally necessary.

The absence of discussion in the intervening years would suggest this
idea is not one to be taken very seriously.

73's
Richard Clark, KB7QHC

using trees as antenna
 

"Richard Clark" wrote in message
...
On 26 Sep 2006 01:30:44 -0700, "
wrote:


There was some discussion of this in this group about 8 - 10 years
ago. Most thought it was absurd. Some thought it was possible. None
considered it very effective. One reported experience (and he was
thoroughly mocked). The tree was treated as a vertical radiator, and
was fed against ground and into a nail to penetrate to the conductive
fiber. Some form of matching was generally necessary.

The absence of discussion in the intervening years would suggest this
idea is not one to be taken very seriously.

73's
Richard Clark, KB7QHC


The Livewire Yahoo Group had some discussion of this a year or two back. I
think it was a kind of spinoff of their experiments with Ionic Liquid
Antennas. If you are interested enough they probably have all that in their
archives.

Harold
KD5SAK

using trees as antenna
 

Some years ago, there was an article in QST about using trees as
antenna. There was a sort of toroidal winding in the air, the tree
beeing in the center. If I remember well, the article reported
experiences in the army.

Do you remember ? Can you give me more information ?

Thanks a lot !


The Military certainly did experiment and use such systems, particularly
during the Vietnam war.

There are several papers floating about on the subject, such as those from
the United States Army Electronics Command (ECOM):

"The Effects of Foliation on Transmission from a Toroid-coupled Tree", ECOM
Report No. 3473, September 1971
"Signal Propagation at 400 kHz using an Oak Tree with a HEMAC as an
Antenna", ECOM Report No. 3504, November 1971

"Performance of Trees as Radio Antennas in Tropical Jungle Forests", ECOM
Report No. 3534, February 1972

"Utilization as RF-Antennas of Live and of Lifeless Structures in Natural
and in ManMade Jungles", ECOM Report No. 4133, June 1973



73

Jeff

using trees as antenna