Marconi_crystal_radio_receiver.jpg
Summary
Description Marconi crystal radio receiver.jpg |
English:
Marconi type 103
crystal radio
receiver, used with the Marconi company's spark transmitter systems during the pioneering
wireless telegraphy
era of radio around 1920. The
cat's whisker detector
is visible at top. This radio used an inductively-coupled antenna transformer circuit, which improved the selectivity (Q factor) of the receiver, allowing interfering stations near the desired station to be rejected. The "short wave condenser" tuned the primary coil, the "intermediate condenser" tuned the secondary. The "aerial tuning inductance" knob selected taps on the coil winding to adjust the
impedance match
between the antenna and the receiver. The "Billi condenser" was a decoupling capacitor across the earphone leads, which smoothed the audio signal from the detector, removing the residual RF carrier pulses. The "potentiometer" applied an adjustable bias voltage from a battery across the detector, to make it more sensitive.
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Date | |
Source | Downloaded 2010-03-15 from Elmer Eustice Bucher (1917) How to Pass U.S. Government Wireless License Examinations, 4th Ed. revised , Wireless Press, Inc., New York, p.68 on Google Books |
Author | Elmer Eustice Bucher |
Permission
( Reusing this file ) |
Public Domain in USA - published prior to 1923 in USA |
Licensing
Public domain Public domain false false |
This media file is in the
public domain
in the
United States
. This applies to U.S. works where the copyright has expired, often because its first
publication
occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See
this page
for further explanation.
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