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Query: spark gap
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Details Guglielmo Marconi's foundational contributions to radio communication, highlighting his 1898 Patent **7777** which introduced tuning circuits for independent simultaneous communications. Chronicles the historic transatlantic reception of the Morse code letter 'S' on December 12, 1901, from Poldhu, Cornwall, to St. John's, Newfoundland, a distance of over _3,500 kilometers_. The exhibit showcases early Marconi 10-inch spark transmitters, identical to those used on the _Titanic_, alongside Canadian Marconi crystal detector models. It also features high-end commercial receivers like the IP501, weighing **87 pounds** and originally priced at $595.00, demonstrating the robust construction and technological advancements of the era.
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The details of the spark gap transmitter and its history: how it was invented, developed and used.
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Chronicles the operational history of Cullercoats Radio, established in 1906 under _Marconi_ license, detailing its initial use of a spark-gap transmitter feeding a **200-foot** wooden mast. Documents the station's transition in 1915 to Marconi Wireless and a 1929 upgrade to a valve-type transmitter. Explains its later role as a British Telecom (BT) Maritime Radio Station, callsign GCC, serving as a receiving site with transmitting aerials at Hartley. Highlights the demolition of the commercial mast in 2000 and the site's subsequent sale. Features the Tynemouth Radio Club (GX0NWM) operating special event stations like GB4MPC for International Marconi Day from Marconi Point. Includes a historical QSL card confirming a QSO on **7.016 MHz** in 1936.
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Morse News reads RSS/Atom messages and translates them into Morse code, playable as CW radio tones, spark-gap sounds, telegraph clicks, or via a physical telegraph sounder. It supports Farnsworth effects, natural American Morse timing, and realistic audio enhancements. Twitter integration allows user-generated Morse messages.
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Early 20th-century transatlantic wireless communication efforts involved distinct technical approaches by Reginald Fessenden and Guglielmo Marconi. Marconi's systems, operational until approximately 1912, primarily utilized _spark technology_ for wireless telegraphy, facilitating Morse code communication between ships and across oceans. His Poldhu station in December 1901 radiated signals in the MF band around 850 kHz, later evolving to 272 kHz in October 1902, and eventually 45 kHz by late 1907 with increasingly larger antenna structures like the pyramidal monopole and capacitive top-loaded arrays. Fessenden, conversely, focused on _continuous wave transmission_ for wireless telephony, recognizing its necessity for speech. His transatlantic experiments in 1906 employed synchronous rotary-spark-gap transmitters and 420-foot umbrella top-loaded antennas at Brant Rock, MA, and Machrihanish, Scotland, tuned to approximately 80 kHz. Fessenden later utilized the _Alexanderson HF alternator_ at 75 kHz by late 1906 for pure CW transmission, integrating a carbon microphone for amplitude modulation. Receiver technology also differed, with Marconi initially relying on untuned coherer-type detectors, later developing the magnetic detector in 1902, while Fessenden's CW approach necessitated more advanced detection methods.