The CV51 was based on the M-OV experimental type E1320 and here we have an A1320 - possibly the A indicating a production version. The Y65 is the normal M-OV commercial version.
The target voltage range is 180 to 250 Volts, and the control range on the grid is 11 Volts change.
The Osram paper label.
The triode voltage amplifier is in the centre of the vertical stack.
The heater is a single insulated strand, four lengths pass through the cathode tube. The anode of the triode is attached to the deflecting electrode within the target.
The screen end, note that the cathode tube is uncoated between the two sections.
The classic envelope is 38 mm in diameter, and excluding the IO base pins, is 90 mm tall.
