He recieved the first trans-Atlantic radio signal on December 12 1901 in Newfoundland, Canada using a 400-foot kite-supported antenna to recieve and a spark-gap transmitter using a frequency of approximately 500KHz; it was Morse code for the letter "S." 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.