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- December 14, 2008 at 8:58 pm #7207
Here’s an interesting blurb I found on another site where the author presents some information about using trees as both transmit and receive antennas.
Here’s an interesting blurb I found on another site where the author presents some information about using trees as both transmit and receive antennas.
http://www.w5jgv.com/tree_antenna/Robert%20Hand.pdf
I don’t take this too seriously but it is fun to ponder.
Neil
December 15, 2008 at 2:10 am #16962WEAK-AM
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Total posts : 45366Neil,
This is no joke! I have been demonstrating this to my friends for several years.
Do this: Go for a walk down a tree-lined street. Bring along a Walkman or similar reasonably sensitive portable AM radio. The best demonstrations are with weak but audible stations, particularly on the low end of the dial. Here in northern IL, WILL-AM 580 is a good example. Walk up to a tree and hold the radio against it, with the ferrite bar parallel to the trunk. Also try moving the radio up and down and to various points such as the places where limbs branch out. The best results are had with large trees having a thick trunk (3 feet or more is great)! If one tree doesn’t do it, keep trying until you find one that does. You will!
If the tree is a hot performer, you will probably find that the tree swamps out the directionality of the internal ferrite bar antenna. I have not done a definitive study about which brands and models of trees work the best (!) but this would be an interesting topic to explore. I think there are other factors that come into play, such as the moisture content of the ground, the amount of sap in the tree, etc. Often trees are near power lines running along the parkway, and I suspect some signals are coupled in from those.
The amplification factor can be as little as a few dB to 10 dB or more, just judging by ear. So give it a try and tell us what you find out! I promise, I am not kidding!
December 15, 2008 at 8:47 am #16963radio8z
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Total posts : 45366WEAK-AM,
Thanks for the followup on this. As noted I was a bit skeptical but your information lends credibility to the idea.
I live on a wooded lot and have plenty of chances to play with this, perhaps when the trees and I thaw in the spring. The Ash trees here have root systems which are shallow and extend many meters from the tree trunks…nature’s ground plane?
Neil
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