The T15 triode is contained within a clear glass balloon. The filament is rated at up to 6.0 Volts depending on use. The construction follows the earliest designs in that a horizontal bright cylinder anode has a stout wire helix grid running through it which is in turn pierced by a single strand of tungsten filament.

The balloon envelope is 53 mm in diameter and, excluding the B4 base pins, is 94 mm tall.

This exhibit was last updated on 07 August 2006