There were many who made important contributions to early radio technology. Scottish physics professor James Clerk Maxwell was the theoretician who in the 1860s described the relationship between electricity and electromagnetism. German physicist Heinrich Hertz confirmed this relationship experimentally in 1887 by showing that sparks created with an inductor could be reproduced some distance away with the help of an antenna. In 1890, Édouard Branly, a French physics professor, showed that a discharge affects the iron filings in a small tube, a coherer, and this was later to find general use as a detector in radio communication. Russian Alexander Popov constructed the first radio receiver in 1894.
Another notable figure was Nikola Tesla, a Serbian-born cosmopolitan who spoke eight languages. He worked for many years in the US, as a colleague of Thomas Edison, for instance, and was a close friend of Mark Twain. Tesla is best known for his invention of the alternating-current electric motor and various methods of distributing alternating current. But he also succeeded in producing radio waves and receiving them – a court judgment in the US identifies Tesla and not Marconi as the inventor of radio.
MAKE THINGS HAPPEN
Marconi’s indisputable ability was being able to piece together and combine findings for which the theoreticians did not always see any use. Like Bell, he was the entrepreneur needed to create commercial opportunities and make things happen.
Sweden realized quickly that the British were beginning to equip their ships with radio equipment, and in 1899 it launched its own experiments with spark technology. The following year, during trials in the Stockholm archipelago, vessels up to 30 kilometers apart made contact with two devices using Braun’s system.
Developments in Sweden were undertaken above all by Charles Léon de Champs and Ragnar Rendahl. The former, a navy lieutenant, was posted in 1901 to the navy’s torpedo division to develop the navy’s radio system. The latter came from Värmland and began his studies at the Royal Institute of Technology in Stockholm but graduated in Berlin in 1900 and soon became head of the laboratory in the department of wireless telegraphy at AEG (Allgemeine Elektricitäts-Gesellschaft).
De Champs tried at first to establish contact with Marconi in an attempt to buy equipment for the Swedish navy. After his approaches had been rebuffed, he was more successful in his contacts with AEG, where Rendahl had quickly established a reputation as an eminent designer. In 1908 he returned to Sweden after de Champs had offered him a post as marine engineer at the torpedo division. Rendahl’s achievements there led him to become one of the great pioneers in the early history of radio in Sweden.
Alexander Popov launched a radio station on the island of Gogland in the Gulf of Finland during the winter of 1900. Over three months, 440 official telegrams were transmitted wirelessly to Kotka in Finland, a distance of about 40 kilometers.
Author: Svenolof Karlsson & Anders Lugn
