The GA16 photocell from Baird was made in England probably in the 1930s. The paper label is the only information we have so far and it shows the maximum anode voltage as 160 Volts. The serial number is 4,075 indicating that a fair few were manufactured either for television or industrial use.
The anode is the wire ring. The anode is at right angles to the pin 1 and pin 2 axis of the base. The cap between the anode supports looks to have carried the photo-sensitive material that has been fired onto the inside of the glass.
Side view of the anode with the cathode coating the glass.
The wide glass tube envelope is 25 mm in diameter, and excluding the B4 base pins is 56 mm tall.
