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Morse code. Morse code is a telecommunications method which encodes text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs. [3] [4] Morse code is named after Samuel Morse, one of the early developers of the system adopted for electrical telegraphy .
World War II cryptography. Cryptography was used extensively during World War II because of the importance of radio communication and the ease of radio interception. The nations involved fielded a plethora of code and cipher systems, many of the latter using rotor machines. As a result, the theoretical and practical aspects of cryptanalysis, or ...
Wireless telegraphy or radiotelegraphy, commonly called CW ( continuous wave ), ICW (interrupted continuous wave) transmission, or on-off keying, and designated by the International Telecommunication Union as emission type A1A or A2A, is a radio communication method. It was transmitted by several different modulation methods during its history.
The earliest practical use of crystal radio was to receive Morse code radio signals transmitted from spark-gap transmitters by early amateur radio experimenters. As electronics evolved, the ability to send voice signals by radio caused a technological explosion around 1920 that evolved into today's radio broadcasting industry.
The procedure signs below are compiled from the official specification for Morse Code, ITU-R M.1677, International Morse Code, [1] while others are defined the International Radio Regulations for Mobile Maritime Service, including ITU-R M.1170, [8] ITU-R M.1172, [4] and the Maritime International Code of Signals, [5] with a few details of their ...
Golden Age of Radio. Girl listening to vacuum tube radio during the Great Depression. Prior to the emergence of television as the dominant entertainment medium in the 1950s, families gathered to listen to the home radio in the evening. The Golden Age of Radio, also known as the old-time radio ( OTR) era, was an era of radio in the United States ...
Visual mnemonic charts have been devised over the ages. Baden-Powell included one in the Girl Guides handbook in 1918. A contemporary Morse code chart. Here is a more up-to-date version, ca. 1988: Other visual mnemonic systems have been created for Morse code, mapping the elements of the Morse code characters onto pictures for easy memorization.
Signal lamp training during World War II. A signal lamp (sometimes called an Aldis lamp or a Morse lamp) is a visual signaling device for optical communication by flashes of a lamp, typically using Morse code. The idea of flashing dots and dashes from a lantern was first put into practice by Captain Philip Howard Colomb, of the Royal Navy, in 1867.