The VT94 is a medium power RF triode designed for HF service up to 6 MHz. The carbonised anode is held in place by two T shaped supports. These supports fit to a circular band that fits around the pinch and is held in place by a nut and bolt. Clearly a hand assembled valve. At the top of the envelope is a reduced diameter section to the envelope. The top mica locates in this part of the envelope to give added mechanical stability.
Within the region above the pinch can be seen the multiple hairpin loops of the oxide coated filament.
My late father-in-law always referred to the Air Ministry stamp on objects as Arthur Mitchell.
This oblique look into the anode space shows the filament loops and substantial wire forming the grid. The T shaped anode support is also clearly seen.
Another view of the lower mica and grids etc.
The L4 base seen full on. The connections can be seen to be made to brass shim that connects to the sprung pins that are themselves securely attached to the composition base. The L4 base is 56 mm square and 25 mm thick. The locating circle at the base of the moulding is 43 mm in diameter and 11 mm thick.
The wide glass tube envelope is 50 mm in diameter, and excluding the L4 base pins is 100 mm tall.