The CV1343 is an indirectly heated HF pentode and the base valve for the design was a modified 1937 KTZ73. The old Army service code is ARP38 and the GPO code is POVT149. Note that this valve has a 4.0 Volt heater and the later KTZ73 has a 6.3 Volt heater.
The KB/Z identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the Z identifies the maker as MO Valve Company, Hammersmith.
The reverse is plain zinc paint.
Looking through the top the tops of the three grids can be seen as can the cylindrical cathode tube.
The wide glass tube envelope is 29 mm in diameter and, excluding the IO base pins, is 80 mm tall.
