▼ Menu

    
Extras ▼

This exhibit is an early type T Pliotron for transmitter use. The pinch has the designation VT-12 written on it.

VT-12 is a low power oscillating triode used for telephone transmitters and was made by General Electric as a substitute for the Western Electric VT2.

The type no VT-12 was designated by the US Signal Corps. It was only used briefly before being replaced with the VT-14 which has a different filament design.

Thanks to Joe Gruber for sending the image.

The balloon envelope is 35 mm in diameter and, excluding the UV base pins, is 101 mm tall.

References: J Gruber, ³⁰⁰² & ¹⁰⁴⁷. Type VT-12 was first introduced in 1918. See also 1918 adverts.

Absolute Maximum Operating Conditions^¶