Guglielmo Marconi, (1874-1937), was the Italian-born founder of the Marconi corporation and the 1909 recipient of the Nobel Prize in physics. Although many scientists and inventors contributed to the invention of wireless telegraphy, including Ørsted, Faraday, Hertz, Tesla, Edison, and others, Marconi's was the first practical system to achieve widespread use, so he is often credited as the "father of radio".
He received the first trans-Atlantic radio signal on December 12 1901 in St Johns, Newfoundland, Canada using a 400-foot kite-supported antenna for reception. The transmitting station in Poldhu, Cornwall used a spark-gap transmitter to produce a signal with a frequency of approximately 500KHz and a power of 100 times more than any radio signal previously produced. The message received was three dots, the Morse code for the letter S. To reach Newfoundland the signal would have to bounce off the ionosphere twice.
Dr. Jack Belrose has recently contested this, however, based on theoretical work as well as an actual reenactment of the experiment; he believes that Marconi heard only random atmospheric noise and mistook it for the signal. Marconi didn't achieve fully reliable transatlantic communication until 1907.