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  2. Morse code - Wikipedia

    en.wikipedia.org/wiki/Morse_code

    Morse code is a method used in telecommunication to encode 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 . International Morse code encodes the 26 ...

  3. Amateur radio - Wikipedia

    en.wikipedia.org/wiki/Amateur_radio

    Morse Code is no longer tested in the U.S. Once the exam is passed, the FCC issues an Amateur Radio license which is valid for ten years. Studying for the exam is made easier because the entire question pools for all license classes are posted in advance.

  4. Morse code abbreviations - Wikipedia

    en.wikipedia.org/wiki/Morse_code_abbreviations

    An amateur radio Morse code conversation example. To make Morse code communications faster and more efficient, there are many internationally agreed patterns or conventions of communication which include: extensive use of abbreviations, use of brevity codes such as 92 Code, RST code, Q code, Z code as well as the use of Morse prosigns. The ...

  5. Telegraph key - Wikipedia

    en.wikipedia.org/wiki/Telegraph_key

    A telegraph key or Morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. Keys are used in all forms of electrical telegraph systems, including landline (also called wire) telegraphy and radio (also called wireless) telegraphy. An operator uses the telegraph key to ...

  6. American Morse code - Wikipedia

    en.wikipedia.org/wiki/American_Morse_code

    American Morse code. 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 "American" qualifier was added because, after most of the rest of the world adopted " International Morse Code ...

  7. Continuous wave - Wikipedia

    en.wikipedia.org/wiki/Continuous_wave

    Multiplexing. v. t. e. A continuous wave or continuous waveform ( CW) is an electromagnetic wave of constant amplitude and frequency, typically a sine wave, that for mathematical analysis is considered to be of infinite duration. [1] It may refer to e.g. a laser or particle accelerator having a continuous output, as opposed to a pulsed output.

  8. Beat frequency oscillator - Wikipedia

    en.wikipedia.org/wiki/Beat_frequency_oscillator

    Add-on 455 kHz homemade BFO board. In a radio receiver, a beat frequency oscillator or BFO is a dedicated oscillator used to create an audio frequency signal from Morse code radiotelegraphy ( CW) transmissions to make them audible. The signal from the BFO is mixed with the received signal to create a heterodyne or beat frequency which is heard ...

  9. Instructograph - Wikipedia

    en.wikipedia.org/wiki/Instructograph

    Instructograph. The Instructograph was a paper tape -based machine used for the study of Morse code . The paper tape mechanism consisted of two reels which passed a paper tape across a reading device that actuated a set of contacts which changed state dependent on the presence or absence of hole punches in the tape. The contacts could operate ...