Nikola Tesla
It has been hypothesized that he may have intercepted Guglielmo Marconi's European experiments
Colorado, U.S.
It has been hypothesized that he may have intercepted Guglielmo Marconi's European experiments in July 1899—Marconi may have transmitted the letter S (dot/dot/dot) in a naval demonstration, the same three impulses that Tesla hinted at hearing in Colorado—or signals from another experimenter in wireless transmission.