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Amateur radio or Ham radio is a hobby enjoyed by thousands of people throughout the world. A Ham radio amateur uses radio equipment to communicate with other radio amateurs for recreation, public service and self-training. Amateur radio enthusiasts have made significant contributions to science, industry and engineering. The research done by them has founded new industries, built economies and saved lives.
Amateur radio operators enjoy personal two-way communications with friends, family members or complete strangers; they support the larger public community with emergency and disaster communications. The term "amateur" is not a reflection on the skills of the participants, which have often quite advanced knowledge of electronics and radio theory; rather, "amateur" indicates that amateur communications are not allowed to be made for commercial or money-making purposes.
Many individuals (inventors, engineers, developers, businessmen) have contributed to the development of radio communications and thus the origins of this invention are multiple and controversial. Thomas Edison applied in 1885 to the U.S. Patent Office for a patent on a wireless telegraphy system which anticipated later developments in the field. Nikola Tesla (1856-1943) was able to detect signals from the transmissions of his New York lab at West Point (50 miles away).