File:Large loop antenna 1926.png

From Wikimedia Commons, the free media repository
Jump to navigation Jump to search

Original file (314 × 753 pixels, file size: 67 KB, MIME type: image/png)

Captions

Captions

Add a one-line explanation of what this file represents

Summary

[edit]
Description
English: A large indoor loop antenna for broadcast receivers, from a 1926 advertisement in a radio magazone. Dimensions: 8 in x 7 in x 30 in. high. It consists of many turns of fine wire on a mahogony frame, with a second loop inside the first. The second loop could be used to apply feedback from the detector tube of a regenerative receiver to the loop, increasing the Q. Before World War 2 most medium wave (AM) radios used air-core loop antennas, which had to be large to bring in distant stations. The invention of high permeability ferrite cores allows the loop antennas used in modern AM radios, called ferrite loopsticks, to be much smaller, and be enclosed inside the radio's case. This antenna was called the Aero-Loop, manufactured by Utt-Williams Electrical Products Co. and distributed by Scott Sales Co. and sold for $12.50.
Date
Source Retrieved July 6, 2014 from Radio News magazine, Ziff-Davis Publishing Co., New York, Vol. 7, No. 9, March 1926, p. 1340 on American Radio History site
Author Unknown authorUnknown author
Permission
(Reusing this file)		 This image is from an advertisement for Scott Sales Co. without a copyright notice published in a 1926 magazine. In the United States, advertisements published in collective works (magazines and newspapers) are not covered by the copyright notice for the entire collective work. (See U.S. Copyright Office Circular 3, "Copyright Notice", page 3, "Contributions to Collective Works".) Since the advertisement was published before 1978 without a copyright notice, it falls into the public domain.

Licensing

[edit]
This work is in the public domain in the United States because it was published in the United States between 1929 and 1977, inclusive, without a copyright notice. For further explanation, see Commons:Hirtle chart as well as a detailed definition of "publication" for public art.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.

العربية ∙ беларуская (тарашкевіца) ∙ čeština ∙ Deutsch ∙ Ελληνικά ∙ English ∙ español ∙ français ∙ Bahasa Indonesia ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ Nederlands ∙ português ∙ русский ∙ sicilianu ∙ slovenščina ∙ ไทย ∙ Tiếng Việt ∙ 中文（简体） ∙ 中文（繁體） ∙ +/−

Flag of the United States
Flag of the United States

File history

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

Date/TimeThumbnailDimensionsUserComment
current03:16, 7 July 2014Thumbnail for version as of 03:16, 7 July 2014314 × 753 (67 KB)Chetvorno (talk | contribs)User created page with UploadWizard

You cannot overwrite this file.

There are no pages that use this file.

File usage on other wikis

The following other wikis use this file:

Metadata

This file contains additional information such as Exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.

Retrieved from "https://commons.wikimedia.org/w/index.php?title=File:Large_loop_antenna_1926.png&oldid=934373221"