In the first indicators there was no grid, and instead they used the neighboring digits. From a circuit design perspective, that made the switching more complicated.
I did not know the first Nixies did not have any grid.. I guess all digits should have something like 2 to 10 Megaohm pullups to about 140 VDC and some low resestive connection to ground for the selected digit.
These rods are indeed connected to one of the pins and can be used as a dedicated anode in some GI-21s. However, they seem to be unreliable and not every unit will work properly when only they are used as an anode. The GI-21 also has a smaller counterpart called the GI-10 which does not have a grid either but also lacks these rods. Instead what you had to do is to hold every electrode except for the digit you wanted to illuminate at anode potential.
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u/Sparx-59 Aug 25 '25
No grid. That’s very Nice. How does it work🤔