The GC10B is a Dektron counting tube where the application of a pair of input pulses causes the neon discharge to move around the pin circle. The position of the glow is the readout. At the end of a revolution the tube generates an output pulse to drive another tube. The GC10B can accept pulses up to 4,000 per second.
The base and pinch showing the two getter holders.
The connections to the guides, where each set is welded to a disc held between ceramic spacers.
A closer look at the connections. The insulated centre is the connection for the common cathode.
The central cathode disc with the 10 anodes and 20 guides around the outside.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 85 mm tall.