Sensibly equivalent¶ to:
2B21 2X2A 879 CV597 CV3748 VT-119
The 2X2 is an EHT half wave rectifier. We also have the 2X2A variant in the museum.
The 2.5 volt heater indicates that it would be powered by a special heater winding of high insulation. Such a valve would have found application in oscilloscopes etc.
Within the anode bell can be seen the coated cathode tube. This has a small diameter in relation to the bell as the emission required is low but the gap needs to be large to avoid breakdown when a high Voltage is applied.
The classic envelope is 36 mm in diameter and, excluding the UX4 base pins, is 97 mm tall.
References: Data-sheet, 3002 & 1043. Type 2X2 was first introduced in 1939. See also 1939 adverts.
Absolute Maximum Operating Conditions¶
Updated January 03, 2022.