Editing Guglielmo Marconi (section)

====Developing radio telegraphy====
[[File:Marconi's first radio transmitter.jpg|thumb|Marconi's first transmitter incorporating a [[monopole antenna]]. It consisted of an elevated copper sheet ''(top)'' connected to a Righi spark gap ''(left)'' powered by an [[induction coil]] ''(centre)'' with a [[telegraph key]] ''(right)'' to switch it on and off to spell out text messages in [[Morse code]].]]

At the age of 20, Marconi began to conduct experiments in radio waves, building much of his own equipment in the attic of his home at the Villa Griffone in Pontecchio (now an administrative subdivision of [[Sasso Marconi]]), Italy, with the help of his butler, Mignani. Marconi built on Hertz's original experiments and, at the suggestion of Righi, began using a [[coherer]], an early detector based on the 1890 findings of French physicist [[Édouard Branly]] and used in Lodge's experiments, that [[Electrical resistance and conductance|changed resistance]] when exposed to radio waves.<ref name="Brown141">{{cite book|last=Brown|first=Antony|title=Great Ideas in Communications|publisher=D. White Co.|year=1969|page=141}}</ref> In the summer of 1894, he built a storm alarm made up of a battery, a coherer, and an electric bell, which went off when it picked up the radio waves generated by lightning.

Late one night, in December 1894, Marconi demonstrated a radio transmitter and receiver to his mother, a set-up that made a bell ring on the other side of the room by pushing a telegraphic button on a bench.<ref>{{cite web|url=http://www.radiomarconi.com/marconi/xmarconi.html|title=Guglielmo Marconi, padre della radio|archive-url=https://web.archive.org/web/20130602093434/http://www.radiomarconi.com/marconi/xmarconi.html|archive-date=2 June 2013|website=Radiomarconi.com|url-status=usurped|access-date=12 July 2012}}</ref><ref name="Brown141"/> Supported by his father, Marconi continued to read through the literature and picked up on the ideas of physicists who were experimenting with radio waves. He developed devices, such as portable transmitters and receiver systems, that could work over long distances,<ref name="ABC-CLIO"/> turning what was essentially a laboratory experiment into a useful communication system.<ref>[[#Hong|Hong]], p. 22</ref> Marconi came up with a functional system with many components:<ref>Marconi delineated his 1895 apparatus in his Nobel Award speech. See: Marconi, "[http://nobelprize.org/nobel_prizes/physics/laureates/1909/marconi-lecture.html Wireless Telegraphic Communication: Nobel Lecture, 11 December 1909.]" Nobel Lectures. Physics 1901–1921. Amsterdam: Elsevier Publishing Company, 1967: 196–222. p. 198.</ref>
* A relatively simple [[oscillator]] or [[spark-gap transmitter|spark-producing]] radio transmitter;
* A [[wire]] or metal sheet capacity area suspended at a height above the ground;
* A [[coherer]] receiver, which was a modification of [[Édouard Branly]]'s original device with refinements to increase sensitivity and reliability;
* A [[telegraph key]] to operate the transmitter to send short and long pulses, corresponding to the dots-and-dashes of [[Morse code]]; and
* A telegraph register activated by the [[coherer]] which recorded the received [[Morse code]] dots and dashes onto a roll of paper tape.

In the summer of 1895, Marconi moved his experiments outdoors on his father's estate in Bologna. He tried different arrangements and shapes of antenna but even with improvements he was able to transmit signals only up to one half-mile, a distance Oliver Lodge had predicted in 1894 as the maximum transmission distance for radio waves.<ref>[[#Hong|Hong]], p. 6</ref>