Armstrong_circuit.png
Summary
Description Armstrong circuit.png |
English:
Armstrong's "feed back" drawing that convinced the patent courts to uphold his invention.
|
Date |
before 1922
date QS:P,+1922-00-00T00:00:00Z/7,P1326,+1922-00-00T00:00:00Z/9
; drawing copied from a 1922 magazine publication
|
Source | Radio Broadcast vol.1 no.1 |
Author | Edwin H. Armstrong |
Licensing
Public domain Public domain false false |
This work is in the
public domain
in the
United States
because it was
published
(or registered with the
U.S. Copyright Office
) before January 1, 1929.
Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file
must
have an additional
copyright tag
indicating the copyright status in the source country.
Note: This tag should not be used for sound recordings. PD-1923 Public domain in the United States //commons.wikimedia.org/wiki/File:Armstrong_circuit.png |