Neil Boucher
The fifth Tools of Science meeting for 2007 will be held at 6pm on Tuesday July 24 in Parnell (7) LR234* The speaker will be Neil Boucher and the topic:
Prehistory of Radio
Radio in 1866
The official story is that Heinrich Hertz, born in 1847 was the first to send and receive radio signals between 1885 and 1889. Actually it had been done twice before in 1866 by Mahlon Loomis and in 1879 by David E Hughes. Here we look at the intriguing system developed by Loomis.
Mahlon Loomis His Transmitter/Receiver
At first glance it would appear that since there is no detector in the system, only DC or low frequency pulses could be transmitted. Many have speculated on whether or not Loomis did achieve his claimed transmission distance of 40 + kilometers. Unfortunately Loomis left no detailed descriptions of his hardware, nor did those who later repeated his experiments (and claimed success).
Finding a lot of speculation and very little substance from a number writers over the years who were either proponents of detractors of the Loomis claims I undertook to revisit the experiments in 2005. At the same time I undertook a theoretical study of his results to see whether the claims were even reasonable, based on either inductive transmission (electric or magnetic) or with true RF. The results of the theoretical study indicated that not only was it possible for this system to work, but that given reasonable assumptions about the sensitivity and construction of the telegraphic galvanometers available at the time, the atmospheric charges that the kite could harness, and the atmospheric background noise levels, it could well be concluded that this system could be made to work and could have been the first radio system even built. Interestingly the theoretical study also imposed constraints on the design of the galvanometer, that meant that only one type of construction of this instrument (and a number of types of galvanometer would have been available at the time) would permit the system to work.
Two vintage galvanometers, one of which makes a fine Loomis detector, the other does not.
Neil Boucher is an Electrical Engineer and author of several books on telecommunications including The Cellular Radio Handbook, now in its 4th edition. His books are published by John Wiley, New York. He is currently engaged in the development of a non-voice sound recognition system, to be used for the identification of rare parrots and other wildlife.
His interest in the Loomis system stemmed from the writing of an as yet unpublished book on radio history. He has undertaken to resolve the controversial claims and counter claims by many of radio before Hertz, and has concluded that two of the pre-radio agesystems were viable and almost certainly did work as described by their inventors.
Light refreshments will be served after the talk.
*Note change from former venue. As a result of UQ room allocation policy, Tools of Science will no longer have a permanent home, so please note the different venue each time.