The 210RC from Cossor is a high impedance triode broadcast receivers. The original Point One series introduced the RC valve for resistance capacity coupled circuits. The Cossor 'New Process' was introduced in 1929 and our other 210RC carries the diamond label proclaiming this new process. This exhibit is of earlier manufacture and has the wrap around label and the horizontal electrodes.
The BVA logo.
The box anode and single V filament.
Here the close wound grid is easier to see, as is the join in the bright sheet that forms the anode.
The anode seen from below and in this image the grid spacing is mre easily seen. The filament is hooked over a support on the left and anchored in place in folded strips that can be seen on the right.
The balloon envelope is 41 mm in diameter, and excluding the B4 base pins is 80 mm tall.
References: Data-sheet, 1043 & 1040. Type 210RC was first introduced in 1929.