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Friday, June 02, 2017

California Trees Serve as a Successful Antenna System

One example of combing trees with antennas
Experimentation in the transmission and reception of wireless signals with a tree forming the antenna system began here in California during the year 1904.  The two locations for these interesting experiments were in the San Francisco area, and the experimenter was George Owen Squier, who went on to become General George Squier, Chief Signal Officer of the United States Army at its general headquarters in Washington DC.
I (Ray Robinson KVOH) checked the date on this one in case it was April 1st,  but I guess that it really did happen and George Squier really did prove that trees may be used not only to just support an antenna system, but also to actually
perform as antennas themselves.
The twin California locations for his initial series of wireless experiments were Camp Atascadero on the edge of the flowing stream at Atascadero Creek near Santa Barbara California about one hundred miles north of Los Angeles, and also at Fort Mason on the edge of San Francisco Bay.  No doubt the nearby waterways enhanced those wireless transmissions back in the year 1904.
George Squier discovered that the best results in the usage of a tree as the antenna system were obtained by driving a nail into the tree, and attaching a wire to the nail.   The tree needs to be alive, and preferably with a full canopy of leaves; thus with a good flow of internal sap in the trunk of the tree.  A dead tree does not perform satisfactorily as a radio antenna.
During the tragic days of World War 1, some of the Signal Corps wireless stations in different  areas of the United States, and elsewhere, were instructed to experiment with the usage of living trees as a wireless antenna, for  transmitting as  well as for receiving.  It was discovered that the performance of a tree as an antenna was actually equal to that of a random wire, with the added advantage of less static.
After the spate of experimentation in California with the infamous imported Eucalyptus trees from Australia, Squire himself re-began a new series of experiments fifteen years later (1919), this time on the edge of Washington DC.  With the wireless equipment installed in a simple hut and a nearby tree as the antenna, he was able to tune in to wireless signals in Morse Code from across
the Atlantic, from the high powered German station at Nauen, as well as from French and English stations, and also from ships at sea.
Surprisingly, it was discovered that the same tree could be used as the antenna, as well as the grounded counterpoise earthing system.  Simple wire netting used as the earthing counterpoise was also successful.  However, if single wires are laid on the ground as  a counterpoise, the signal from a particular direction was enhanced with an increase in the number of counterpoise
wires in that same direction.  
Best results, he discovered, were obtained when the nail for the antenna was driven into the tree trunk at about two-thirds  of the total height of the tree.  A single nail, preferably copper rather than iron which rusts, works satisfactorily, though a maximum number of six or eight nails does enhance the received signals.  
The received signals are not diminished if additional receivers are hooked directly into the tree trunk.  In addition, it was discovered that the tree antenna can be used equally effectively at any point in the electronic spectrum; longwave, mediumwave or shortwave.
The wireless signals received from a tree are not affected by rain, nor by any other nearby trees, and the type of tree apparently makes no difference.  Local two way wireless communications in Morse as as well as in speech can be readily carried on with the use of a tree at each end for both transmitting and receiving.
Additional scientific experiments in the usage of tropical jungle growth as a radio antenna were conducted by the American army in Panama in 1972.  It was discovered that trees form a better antenna than do ferns or other less developed forms of undergrowth. It was also discovered that the signal strength of a transmitted signal is enhanced if a matching toroidal coil transformer is
inserted between the end of the feeder line and the insertion point into the tree.  
It might also be added that the use of trees as the antenna system for radio signals received attention during the Vietnam War in the 1960's and 1970's.  Although on occasions this activity was another spate of additional experimentation, there were many notable occasion when it became a quick and easy form of practical reality.
These days, there is a small group of international amateur radio operators who are experimenting with tree antennas. This procedure is as much a novelty for them, as it is an experimental procedure. And while we are talking about trees in association with radio, there is another form of electrical experimentation with trees that is of real interest.
In 2005, Chris Lagadinos, president of MagCap in the United States, began experimenting with the use of a tree as a natural source of electrical energy.  He developed his new theory on the fact that trees are often a target for a discharge of lightning during a storm.
He discovered that a low level irregular DC current will flow through a wire that is connected between a spike in a tree and a rod driven into the ground.  The electrical level is measured at around ¾ of a volt, and in a cascade series of smoothing circuits,
the electrical level can actually be increased to around 12 volts at 1 amp.  Interestingly, the power level is highest during the winter when the tree has lots its foliage.
(AWR-Wavescan/NWS 431)