The ZM1175 is a cold cathode numerical indicator tube with flying leads for direct soldering into circuit.
The construction is of a common electrode normally the anode, and a series of shaped cathodes. Each cathode being in the shape of a number from 0 to 9. This were stacked on support rods and each cathode was brought out to its own pin. Energised by 170 volts a open collector based TTL chip would interface between the digital circuitry and the display. As each cathode was connected to ground the glow of the neon gas filling would form round the cathode and through the end window the shape of the numeral would be visible.
Seen face on the array of anode wires are clear. The numerals seem to be jumble of metal when not in operation but once energised and the discharge is seen through a red or orange filter the numerals are clear and distinct.
This image is the clearest example of the construction of these cold cathode indicator tubes. The anode wires are curved to the shape of the envelope. The individual numeral shaped cathodes are held on support struts and insulated from each other by the ceramic rings.
As this exhibit is ex equipment the wires are shorter than originally mede. The remains of the circuit board copper pads can be seen on the wires.
The thin glass tube envelope is 18 mm in diameter, and excluding the base wires is 45 mm tall.
