The 3184 is a most unusual neon tuning indicator. Within the thin glass tube is a wire rod and a circular electrode. To function as a tuning indicator it produced a column of glowing plasma that changed length by virtue of a changing control potential.

The thin glass tube envelope is 12 mm in diameter and, excluding the base pins, is 91 mm tall.

 
Absolute Maximum Operating Conditions

Indicator	Va
	160

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 02 February 2008 {find valves by name}