In our program today, we present our third batch of unusual radio receiving antennas, some of which date way back almost one hundred years. During the year 1925 for example, an unusual experiment was conducted, we presume in the United States, in which the exhaust gas from an airplane engine was used as the receiving and transmitting antenna.
As the news item in Radio News for June 1925 states: The exhaust gas from an aircraft engine is at a very high temperature, which is heavily ionized, and it can therefore be used to conduct electricity. The experiment was considered to be successful, and the procedure was granted a patent.
Over the years, there have been many tests to determine the value of an underground antenna system for the reception of radio signals. In 1927 for example, three consecutive issues of the (then) popular American radio magazine, Radio News (August, September, and October) carried information regarding experiments with underground radio antennas. The purpose of these experiments was to determine the possibility of eliminating static which was often evident in the reception of mediumwave programming.
The Radio News article in 1927 suggested digging a hole three feet in diameter and four feet deep, and to bury a coil of copper wire in the hole. A lead-covered wire connected the buried copper coil to the receiver. According to the advocate of this procedure, Professor Dr. James H. Rogers of Hyattsville MD, unwanted static is almost completely eliminated.
Another similar procedure suggested by Dr. Rogers was to place a long wire horizontally in a shallow trench and then place a metal screen over the antenna wire, though the metal screen does not touch the antenna wire. This experimental procedure, which was also granted a patent, also eliminates most of the static, he declared.
Two other radio men, Mr. J. A Proctor of Lexington MA, and the well-known Frank Conrad of KDKA fame experimented with the use of two out-of-phase receiving antennas of different heights. Both antennas were connected to the same receiver through a complicated system of transformers, and in this way, they claimed, static was reduced.
Another advocate for the reduction of static also patented his procedure, and that was to insert a resistor between the antenna and the receiver, though as he discovered, the signal strength of the received signals was also reduced.
Then there were two men in England, G. A. Morris and B. C. Stevenson who had a different idea, which they also patented. They suggested that the receiving set should have two earthing connections; one, the normal earth connection, and the other an antenna, not erected above the ground, but rather buried in the ground.
We should also add, that amateur radio operator Clem Small KR6A experimented with buried antenna systems many years later, during the year 2001. According to his information, as published in the now inactive American radio magazine Monitoring Times (December 2001, page 78), the same variety of receiving antennas that are in use above the ground, can also be designed and buried beneath ground level. Although reception levels are reduced, he states that underground antenna systems are easier to install than the above-ground level variety.
Interestingly back in the early radio era, many radio operators advocated that their antennas should be polished, preferably every week or two. In this way, it was suggested, that dust and grime are removed from the aerial wire, thus granting better radio reception, they said. That quote was from another now inactive American radio magazine, Popular Communications, September 2006, page 23.
(NWS 705/AWR Wavescan)