The CV220 is a cold cathode four electrode neon discharge tube capable of producing very short duration pulses. The prototype is the 631-P1 and commercially it is the Ferranti NSP1. The circuit in the data-sheet suggests that the main use was in a stroboscope to inspect rotating machinery.
The KB/FRD identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the FRD identifies the maker and factory. The identification of FRD is as yet unknown at the museum.
The general geometry with the anode at the top with the support rods isolated within glass tubes.
The glass tube over one anode support. Other versions use an impregnated fabric sleeve to isolate the anode lead. Also this exhibit has two rods supporting the anode others have a single support.
The anode is a simple cap.
The cathode structure hides the control electrodes.
The wide glass tube envelope is 29 mm in diameter, and excluding the UX4 base pins is 83 mm tall.
