File:Parallel rod push-pull 120MHz oscillator.jpg

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Summary

Description	English: A UHF transmitter from 1938 consisting of two HK-354 triode vacuum tubes in a push-pull tuned-grid tuned-plate oscillator circuit using quarter-wave parallel rod resonant stubs for tuning the grid and plate. The source says the oscillator can produce "high power" on the 2.5 meter (120 MHz) and 5 meter (60 MHz) bands. The plate rods (right) are tuned by a movable shorting strap at the end, while the grid rods (left) are shorted at the bottom and tuned by moving the grid connections up or down. The rods are 2.25 ft (69 cm) long for the 2.5 m band, and 4.5 ft for the 5 m band.
Date	1938
Source	Retrieved October 12, 2014 from W. W. Smith, ed. The Radio Handbook, 5th Ed. published by Radio, Ltd., Los Angeles, 1938, p. 427, fig. 23 on American Radio History website
Author	Unknown authorUnknown author
Permission (Reusing this file)	This book published in 1938 would have the copyright renewed in 1966. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. [1] Search of the Renewals for books for 1965, 1966, and 1967 show no renewal entries for The Radio Handbook. Therefore the copyright was not renewed and it is in the public domain.

Licensing

This work is in the public domain because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the copyright was not renewed. For further explanation, see Commons:Hirtle chart and the copyright renewal logs.
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 (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.

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