Electrical engineering milestone. Transatlantic Radio Signals. At Signal Hill on 12 December 1901 Guglielmo Marconi and his assistant George Kemp confirmed the reception of the first transatlantic radio signals with a telephone receiver and a wire antenna kept aloft by a kite. They heard morse code for the letter "S" transmitted from Poldhc Cornwall. Their experiments showed that radio signals extended far beyond the horizon giving radio a new global dimension for communication in the twentieth century