This pentode only carries the characters 10051 and MVA, no Type designation can be found.
Tests show that the heater, pins 2 and 7, takes 0.22 Amps at 6.3 Volts. The control grid is connected to the top cap as would be expected of a valve used for RF or IF amplification. However, the valve lacks a lower screen as would be found in the EF36 type. See VR56.
Looking face-on to the anode. The cooling fins on the control grid are at the top.
A close-up of the main construction. The anode has four fins at 90 drgrees to one another. The anode box is 15 mm tall and has a maximun width of 21 mm.
The classic envelope is 34 mm in diameter, and excluding the IO base pins is 95 mm tall.
Updated October 21, 2016.