Amateur Radio: 100Years of Discovery
Total Page：16
File Type：pdf, Size：1020Kb
By Jim Maxwell, W6CF Amateur Radio: 100Years of Discovery we approach the new millen- Faraday, heavily influenced Maxwell’s work, ered himself an amateur at heart. Still, he chose nium, it’s a happy coincidence but many of Maxwell’s contemporaries weren’t to devote his life to competing in the commercial that Amateur Radio is now convinced that his new theories were valid. It wireless marketplace; he never operated nor was As almost exactly 100 years old. would take nothing less than rock-solid ex- licensed as an amateur. It seems appropriate to stop for a moment and perimental effort to break down those walls of Back to the original question, we’ll prob- take a thoughtful trip to our beginning years, doubt. The German physicist Heinrich Hertz ably never know who the first Amateur Radio and even before. Why should we bother, you did just that, performing a series of classic operator was, but the Englishman Leslie Miller ask? Well, for many this will be a pleasant and experiments in the late 1880s during which he is surely a leading contender for that honor. nostalgic look back to the early days, the early generated, detected, and measured the proper- Leslie Miller has a solid place in amateur days, of course, being any day earlier than today! ties of electromagnetic waves predicted by history as the first person to have published a Moreover, as will be seen as we progress through Maxwell’s equations. Hertz, though, had no description of a simple-to-build transmitter and the events of this past century, there is much to particular interest in those waves except for the receiver for an amateur (and he used that word) be learned from our history. As Confucius once intellectual challenges their discovery provided. audience. His article appeared in the January said, “Study the past if you would divine the Development of radio for the use of mankind 1898 issue of The Model Engineer and Amateur future.” was left to others. The race was on. Electrician, published in London. Some of his This article deals, for the most part, with One of the participants in the race to de- readers clearly took the article to heart, for in Amateur Radio in the United States. This re- velop radio was the young Italian Guglielmo the March 1898 issue “E. A.” wrote that he had striction is not due to a lack of interest or a lack Marconi. He had a strong interest in physics a 2-inch spark coil and three solid brass balls, of importance of the broader topic of worldwide and electrical science as a boy. He studied the but needed more construction details. (The three Amateur Radio, but purely for practical reasons. subject in school and became aware of the brass balls were called for in one of the transmit- Consider that Clinton B. DeSoto’s classic 200 possibility of using electromagnetic waves for ter designs given in Miller’s article.) No fewer Meters and Down covers the history of Amateur communicating. In 1894 he started to work on than three more letters on the subject appeared Radio in the US only to 1936—but contains the project in earnest. Two years later he was in 1899 issues of the little magazine. The Yanks 184 pages. in England with what he felt was a useful radio weren’t far behind, with a construction article device. During a demonstration before British in the American Electrician in July 1899. An The 1800s—Prehistory officials Marconi managed to communicate explosion of interest would occur over the next The last few years of the 19th century set the over a distance of 2 miles without wires. It was decade, but as the 19th century drew to a close, stage for rapid development of commercial radio an astonishing feat at the time and it launched Amateur Radio was on its way. and established the foundations of Amateur Marconi’s professional career. The rest, as the Radio. There were numerous early contribu- old saw goes, is history. The ’00s—The Beginning tors to the radio art, such as the great Oersted, Who was the first Amateur Radio operator? As the 20th century began, commercial Ampere, Faraday, Henry, and others. However, We’ll probably never know. Some would say it development gained speed. Marconi spanned discovery really shifted into high gear in 1873 was Marconi. Marconi had a great fondness for the Atlantic with wireless in 1901, using high with the controversial work of the Scotsman Amateur Radio throughout his life, and consid- James Clerk Maxwell (not related to the author of this article!). His work presented his theory of the electromagnetic field. Maxwell was the In 1896 Marconi managed to originator of those sublime equations loved so dearly by students throughout the world. communicate over a distance of (Heaviside also made major contributions to Maxwell’s equations as they appear in modern 2 miles without wires. textbooks, but that’s another story.) In 1901 he spanned the Atlantic. Those who came before him, especially Jan 2000 QST - © Copyright 2010 American Radio Relay League, Inc. - All Rights Reserved power and giant antennas. Amateurs continued The ’10s—Regulation but it took a Hartford, Connecticut ham, Hiram to tinker and experiment with their modest The range of an amateur station in the early Percy Maxim, 1WH (later 1AW) to recognize installations. A detailed construction article 1900s was measured initially by yards, then by that messages could be sent more reliably over appeared in the Boston magazine Amateur Work city blocks. As power increased and technology long distances if relay stations were organized. in June 1902. It’s clear that the experimenters improved, ranges increased so that by 1912 a So, in 1914, the American Radio Relay League at that time had already discovered the skill of well-designed kilowatt spark station had a range was born, and by late 1915 QST started publica- scrounging that amateurs adhere to even today: of perhaps 100 miles. Those with more power tion. The calls “1WH” and “1AW” look strange one of the components recommended in that could work several hundreds of miles. Higher to some today, but they were the norm for the article was baling wire. power generally meant more interference and early years. Commerce Department rules issued These early transmitters all generated RF the clamor for regulation intensified. in 1913 provided for amateur call letters, but by means of discharging a capacitor across a Congress had actually been investigating prefixes were not defined or required. Prefixes gap, creating an oscillatory spark. These early problems related to wireless since 1910. In came later, in the mid to late 1920s. spark transmitters did produce RF, but were 1912, after agonizing appraisal of more than About that same time a miracle in receiver broadband by their very nature, making it dif- a dozen different bills, Congress finally ap- technology appeared on the scene. A New York ficult, and often impossible, for two neighbor- proved the Radio Act of 1912. For the first amateur by the name of Edwin H. Armstrong ing stations to be on the air at the same time. time amateurs were to be licensed. The law invented the tube-operated regenerative receiver Receivers were simple detectors, generally also had a provision that at first was thought in 1913, and in 1915 its design became public coherers, later giving way to the more sensitive could bring the death of Amateur Radio: hams knowledge. This new receiver had greater galena crystal sets. were restricted to the single wavelength of 200 sensitivity than the crystal detectors then in use. There was no regulation during those meters. The general belief in those days was Although vacuum tubes were expensive at the days, of course. Amateur call letters were that long distance performance improved with time, some amateurs started experimenting with 100 self-assigned, and often consisted only of the longer wavelengths. The “short” wavelength of Armstrong’s design. operator’s initials. 200 meters was thought to be useless, and some The year 1914 brought the madness of A hint of what the future held occurred in expected that the amateurs, all crowded around the Great War in Europe. By 1917 the US was 1904 when the Englishman J. A. Fleming devel- this “useless” wavelength, would eventually fully involved and all ham operations in the US oped the first vacuum diode: the Fleming Valve. give up and pursue other interests. ended. The fact that amateurs formed a pool of In 1906 Lee DeForest added a grid to a Fleming The plot didn’t work. Although there was trained radio operators didn’t go unnoticed— Valve to make the first triode, naming it the an initial drop in numbers following the Radio Hiram Percy Maxim made certain of that!—and “Audion.” Audions made very effective detec- Act of 1912, Amateur Radio in the US started some 4000 hams eventually wound up in the tors, but were generally too expensive for most growing again. There were more than 6000 service of the nation. The word “service” is amateurs to use. It wasn’t until some years later amateurs on the air by 1917. important here, for it emphasizes one of the that it was realized that triodes could be made to Some hams had extended their effective fundamental functions of Amateur Radio—to be generate RF. Meanwhile, crystal receivers and range by relaying messages through others, of service to the public and to the nation. spark transmitters ruled the airwaves. The war finally came to a close on Novem- ber 11, 1918.