The Philips D-1 dates to 1920-21 and is a bright emitter triode. The basic operating details are written on the glass as is the fact that it was imported from Holland.
The anode cylinder has a flange at the base that connects to two supports anchored in the pinch.
The grid is fixed to the support along one edge. The filament is clamped into a fold in the support.
The single strand tungsten filament is still in place.
A closer view of the electrodes.
The wide glass tube envelope is 30 mm in diameter, and excluding the B4 base pins is 69 mm tall.
References: Observation & 3002. Type D-1 was first introduced in 1920. See also1920 adverts.