File:Small spark gap transmitter.jpg
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Summary
| Description |
English: Photo of a small spark-gap transmitter, an early type of radio transmitter used during the wireless telegraphy era before 1920. This example is a small demonstration unit from a 1909 book on radio. The source text says that in a practical transmitter the small inductor (coil) shown would be replaced by a larger coil. |
| Date | |
| Source | Downloaded 2010-03-02 from Walter Wentworth Massie and Charles Reginald Underhill (1909) Wireless Telegraphy and Telephony, Popularly Explained, D. Van Nostrand, New York, p.19, fig.7 on Google Books |
| Author | Charles Reginald Underhill |
| Permission (Reusing this file) |
Public domain in USA - published prior to 1923 in USA |
Licensing
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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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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.
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File history
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 00:48, 3 March 2010 | | 788 × 676 (91 KB) | Chetvorno | {{Information |Description=Photo of a small spark-gap transmitter. |Source=Downloaded 2010-03-02 from [http://books.google.com/books?id=2MA3AAAAMAAJ&pg=PA19 Walter Wentworth Massie and Charles Reginald Underhill (1909) ''Wireless Telegraphy and Telep |
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