Image: Split-anode magnetron
Description: Split-anode magnetron tube, an obsolete microwave vacuum tube invented by Albert Hull at General Electric in 1920. One of the first oscillators that could produce frequencies in the gigahertz range, it was used until the modern cavity magnetron was invented in 1940. This tube, used in 1935 in early German experiments in radar was manufactured by AEG/Telefunken and could generate 10 centimeter (3 GHz) microwaves. The image on the right shows the bare tube, about 11 cm tall; on the left shows the tube mounted for use between the poles of a strong permanent magnet.
Title: Split-anode magnetron
Credit: Retrieved October 24, 2014 from "Microwaves to detect aircraft" in Electronics magazine, McGraw-Hill Publishing Co., New York, Vol. 8, No. 9, September 1935, p. 18 on http://www.americanradiohistory.com
Author: Unknown
Permission: This 1935 issue of Electronics magazine would have the copyright renewed in 1963. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. Search of the Renewals for Periodicals for 1962, 1963, and 1964 show no renewal entries for Electronics. Therefore the copyright was not renewed and it is in the public domain.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No
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