The CV5171 is a small three inch electrostatically focused cathode ray tube. This was probably used for an oscilloscope type instrument. The phosphor is a long persistence type and suitable for oscillography or taking photographs off of the screen.
It is typical of these small oscilloscope tubes that the final anode voltage is of the order of 800 Volts. Normally the final anode is held at + 200 V and the cathode and heater hang 600 V below ground. This arrangement has advantages for driving the deflection plates.
The close-up of the tube neck has the electron gun on the left and to the right of the image can be seen the Y deflection plates. The X plates ill follow the Y plates and be closer to the screen. The Y plates are closest to the electron gun as in this position the deflection sensitivity is greatest.
The front of the CRT showing the phosphor creeping round the edge of the envelope. The screen is 70 mm diameter.
See alsoDG7-5 for a phosphor variant of this tube.
The end window envelope is 32 mm in diameter, and excluding the B9G base pins is 142 mm tall.
Reference: Data-sheet. Type CV5171 was first introduced in 1950. See also1950 adverts.