The experimental E4103/E/4 small CRT from GEC was later renamed the 408A and this example carries both designations on the paper label. We also have the E4103/B/4 that has the standard green trace.
Both anodes are connected together and need 1,000 Volts on them. With 1,000 Volts on the anodes the Y sensitivity is 0.09 mm/V and the X sensitivity is 0.1 mm/V. The grid voltage of -25 Volts is to achieve cut-off. The screen has a short persistence blue trace, aimed at the photographic recording of the trace.
The old discoloured adhesive of the label has obscured the electron gun. The Y deflection plates can be seen end on with the width of the X plates seen above.
The X plates seen end on with the Y plates below.
The screen end.
The end window envelope is 38 mm in diameter, and excluding the B9 base pins, is 144 mm tall.
References: Datasheet & 4018. Type E4103/E/4 was first introduced in 1936.