Summary

Valve # 1: Radiotron, Heptode Type 6A7, circa 1935
Valve # 2: Mullard, Heptode Type 6A7, circa 1935

Physical Description

Shouldered glass bulb with top cap and American small 7 pin base, sectioned to reveal the internal structure (Valve # 1). Mounted on display block with an intact example of the same type of valve (Valve # 2).

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