Sylvania 721B  
Written by Accutron on 2017-05-02  

Introduced in the early 1940s, the Sylvania 721B is a large external cavity disc-seal TR cell with an operating frequency range of 2.7-3.3GHz. The 721B is a long-life variant, while the 721A is a standard variant of the same device.

Sylvania 721B disc-seal TR cell.

This article is part of the [Spark Gap Tubes, Trigger Tubes & Passives] exhibit.

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