The DV34 or CV127 is disc seal triode based on the commercial S30A or 3B/401J.
Radiomuseum gives the following details: 40 W max plate dissipation. 15 W output power at 600 MHz. Centre-tapped double-helix thoriated tungsten filament, center tapped for HF connection. Double disc-seal body.
Measuring this valve shows that the filament draws 2.5 A with just 2.0 Volts applied. It is thus possible that this unmarked valve is a special variant of the DV34.
The base pins: the two close together are the filament and the third above and to the left is the centre tap. The metal shell is the grid connection.
The 50 mm disc is the anode connection. It is interesting that this is part way to the final disc seal format as seen in the CV90 etc. Here the triode is quite conventional but the connections are discs.
The anode is connected to the disc with small clips.
The glass distorts the image but the close-wound grid can be seen with the top of the filament in the centre.
The wide glass tube envelope is 29 mm in diameter, and excluding the base pins is 97 mm tall.