Arcturus 551  
Written by Accutron on 2009-05-19  

From 1927 to 1933, Arcturus Radio Company manufactured a family of radio tubes sealed in blue glass balloon envelopes. While most of their devices were various types of triode, Arcturus was also a pioneer of both the variable mu tetrode and the pentode. Introduced in 1931, the Arcturus 551 was the first commercially available variable mu tetrode, and was later copied by numerous other manufacturers. Clones of the 551 include the RCA UY235 and the General Electric 35/51.

Arcturus 551 variable mu tetrode.

This article is part of the [Diodes, Triodes, Tetrodes & Pentodes] exhibit.

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