Radio_receivers_used_in_1920s.png
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Summary
| Description |
English:
Pictures of different types of
radio receivers
used during the 1920s. Unlike today when most radios use a single type of circuit, the
superheterodyne
, during the 1920s many different circuits were used.
|
| Date | |
| Source | Retrieved July 6, 2014 from Radio News magazine, Experimenter Publishing Co., New York, Vol. 7, No. 11, May 1926 p. 1596 from http://www.americanradiohistory.com |
| Author | Unknown author |
|
Permission
( Reusing this file ) |
This image is from an advertisement without a copyright notice published in a 1926 US 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
|
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.
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