Jump to content

File:Marconi crystal radio receiver.jpg

Page contents not supported in other languages.
This is a file from the Wikimedia Commons
From Wikipedia, the free encyclopedia

Marconi_crystal_radio_receiver.jpg (754 × 552 pixels, file size: 134 KB, MIME type: image/jpeg)

Summary

Description
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.
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
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.

United States
United States
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the rule of the shorter term for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See Wikipedia:Public domain and Wikipedia:Copyrights for more details.

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

image/jpeg

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current15:08, 3 May 2021Thumbnail for version as of 15:08, 3 May 2021754 × 552 (134 KB)MaterialscientistFFT
06:28, 17 May 2010Thumbnail for version as of 06:28, 17 May 2010754 × 552 (74 KB)Chetvorno{{Information |Description={{en|Marconi type 103 Wikipedia:crystal radio receiver}} |Source=Downloaded 2010-03-15 from [http://books.google.com/books?id=avXNAAAAMAAJ&pg=PA68 Elmer Eustice Bucher (1917) ''How to Pass U.S. Government Wireless Lice

The following 2 pages use this file:

Global file usage

The following other wikis use this file: