american morse code การใช้

• Initially, train dispatchers issued train orders using American Morse code over telegraph wires.
• Most radio operators used the version of the Code that they were most familiar with the American Morse Code in the United States, and Continental Morse in Europe.
• "' American Morse Code "' also known as Railroad Morse is the latter-day name for the original version of the Morse Code developed in the mid-1840s, by Samuel Morse and Alfred Vail for their electric telegraph.
• The contacts could operate an audio oscillator for the study of International Morse Code ( used by radio ), or a sounder for the study of American Morse Code ( used by railroads ), or a light bulb ( Aldis Lamp-used by Navy ship to ship or by Heliograph ).
• :The article " American Morse code " ( under History ) says the following : The first public message " What hath God wrought " was sent on May 24, 1844, by Morse in Washington to Alfred Vail at the B & O Railroad " outer depot " ( now the B & O railroad museum ) in Baltimore, Maryland.
• An early report on " The International Radio-Telegraphic Convention " in the January 12, 1907, " Electrical World " stated that " Vessels in distress use the special signal, SOS, repeated at short intervals . " ( In American Morse code, which was used by many coastal ships in the United States through the first part of the twentieth century, three dahs stood for the numeral " 5 ", so in a few cases the distress signal was informally referred to as " S5S " .)