File:Marconi Valve Tuner.jpg

No higher resolution available.

Marconi_Valve_Tuner.jpg ‎(529 × 367 pixels, file size: 42 KB, MIME type: image/jpeg)

This is a file from the Wikimedia Commons. Information from its description page there is shown below.
Commons is a freely licensed media file repository. You can help.

Summary

DescriptionMarconi Valve Tuner.jpg	English: The Marconi Valve Tuner, an early unamplified radio receiver manufactured by the Marconi Company for use on ships to receive wireless telegraphy signals. It used the Fleming valve, the first vacuum tube, invented by John Ambrose Fleming as a detector to rectify the radio wave carrier and extract the Morse code "dots" and "dashes", The set had two valves (visible at top); one was a spare in case the other burned out.
Date	1914
Source	Retrieved December 30, 2015 from Rupert Stanley (1914) Textbook on Wireless Telegraphy, Longmans Green and Co., New York, p. 252, fig. 144 on Google Books
Author	Rupert Stanley

Licensing

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
	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.