The CV2006 is a EF55 pentode with flying leads and no screening can. The specification says that selected CV173's have tags welded to the pins and then a PTFE disc is added. This was a GPO requirement.
The valve is a single ended RF pentode with very high mutual conductance and a sharp cut-off. The mutual conductance was almost twice the value for the EF50. It was designed for video bandwidths where the high mutual conductance allows a flatter passband to be achieved whilst maintaining a reasonable stage gain.
The base with red paint location for pin one. The flying leads are attached to standard valve pins.
The control grid is fitted with cooling fins.
The wide glass tube envelope is 32 mm in diameter and, excluding the B9G base wires, is 79 mm tall.
Reference: Datasheet. Type CV2006 was first introduced in 1946.