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  2. Spark-gap transmitter - Wikipedia

    en.wikipedia.org/wiki/Spark-gap_transmitter

    The transmitter works in a rapid repeating cycle in which the capacitor is charged to a high voltage by the transformer and discharged through the coil by a spark across the spark gap. [ 11 ] [ 16 ] The impulsive spark excites the resonant circuit to "ring" like a bell, producing a brief oscillating current which is radiated as electromagnetic ...

  3. Damped wave (radio transmission) - Wikipedia

    en.wikipedia.org/wiki/Damped_wave_(radio...

    A damped wave was an early method of radio transmission produced by the first radio transmitters (spark gap transmitters) which consisted of a series of damped radio waves. Information was carried on this signal by telegraphy, turning the transmitter on and off (on-off keying) to send messages in Morse code.

  4. Spark gap - Wikipedia

    en.wikipedia.org/wiki/Spark_gap

    Spark gap tube. A spark radiates energy throughout the electromagnetic spectrum. Nowadays, this is usually regarded as illegal radio frequency interference and is suppressed, but in the early days of radio communications (1880–1920), this was the means by which radio signals were transmitted, in the unmodulated spark-gap transmitter.

  5. Electronic countermeasure - Wikipedia

    en.wikipedia.org/wiki/Electronic_countermeasure

    The spark-gap transmitters in the Russian stations generated senseless noise while the Japanese were making attempts to coordinate their efforts in the bombing of a Russian naval base. Germany and United Kingdom interfered with enemy communications along the western front during World War I while the Royal Navy tried to intercept German naval ...

  6. File:Spark gap transmitter-Marconi patent 763772 fig 1.png

    en.wikipedia.org/wiki/File:Spark_gap_transmitter...

    English: Spark-gap transmitter circuit from Guglielmo Marconi's controversial patent no. 763772 for a "four circuit" wireless telegraphy radio communication system. The significant innovation of this circuit was the use of two tuned circuits, coupled by a resonant transformer (d,d'), which Marconi called a "jigger".

  7. Radio jamming - Wikipedia

    en.wikipedia.org/wiki/Radio_jamming

    Radio jamming is the deliberate blocking of or interference with wireless communications. [1] [2] In some cases, jammers work by the transmission of radio signals that disrupt telecommunications by decreasing the signal-to-noise ratio.

  8. Wireless telegraphy - Wikipedia

    en.wikipedia.org/wiki/Wireless_telegraphy

    The primitive spark-gap transmitters used until 1920 transmitted by a modulation method called damped wave. As long as the telegraph key was pressed, the transmitter would produce a string of transient pulses of radio waves which repeated at an audio rate, usually between 50 and several thousand hertz. [33]

  9. Magnetic detector - Wikipedia

    en.wikipedia.org/wiki/Magnetic_detector

    The primitive spark gap radio transmitters used during the first three decades of radio (1886-1916) could not transmit audio (sound) and instead transmitted information by wireless telegraphy; the operator switched the transmitter on and off with a telegraph key, creating pulses of radio waves to spell out text messages in Morse code. So the ...