The CV452 was designed as a demodulator and first audio stage in superhet receivers. All stages share the cathode which would be held at ground potential. The prototype was the commercial 6AT6.
From the side the structure is revealed. The central dark cylinder is the triode section and the two wings are the diode anodes, one for AGC and the other for AM signal demodulation. The inverted U shaped wings are mounted on either side of the central cathode tube and are separated from one another by the mica discs.
The KB/DA identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the DA identifies the maker as Mullard Radio Valve Co., Blackburn.
Here the triode grid winding and the form of the diode anodes can be seen. The heater is an insulated wire coil.
Away from the gettering deposit the diode anode shape is clear.
The thin glass tube envelope is 18 mm in diameter and, excluding the B7G base pins, is 47 mm tall.
References: Data-sheet, 3002 & 1040. Type CV452 was first introduced in 1946. See also1946 adverts.
