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GUGLIELMO MARCONI
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Documents
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| The detector | ||
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The adoption of the detector in place of the coherer |
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The detector magnetic 1902
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The
increasing spread of broadcasting without and its commercial use
requiring high reliability of the equipment used. In 1902 Marconi
creates the magnetic detector, revealing a much more 'suitable to the
new state of radio communications. In this apparatus is connected
to a telephone receiver, thanks to which we listen to the points and
lines of the message which must be transcribed by hand.
In most popular model there are two distinct groups of revelation, for two different radio telegraph operators: whether and 'necessary, they can also hear the same message simultaneously and compare as received for greater security.
The magnetic detector reveals the radio signal in a way
completely different from the coherer. A braided wire thin flows
near the poles of two magnets, passing along the axis of two coaxial
windings. The winding more 'internal' linked to satellite and
land, and other 'connected to the telephone receiver. The radio
waves that hit the antenna to Winding cause internal currents
that abruptly change the status of magnetic metal braid: so with
Winding outer pulses are generated through the current perceptible
telephone receiver. The braided metal is scrolled by a drag
mechanism powered by a motor spring.
In 1901-1902 Guglielmo Marconi makes some experiences reception on
board the Cruiser "Carlo Alberto, comparing performance of two and
three coherer magnetic detector, by establishing the superiority of
magnetic devices. The transmitter was in Poldhu, Cornwall, and the
experiences demonstrate the ability to receive the signals even at 1500
km away, despite the intervention of extended continental areas and
mountain ranges.
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