The IV-12 (“NB-12”) is a large seven segment VFD tube produced in Soviet Union by Reflector (known today as Sovtek). It closely resembles the IV-11 but lacks a decimal point and has solid pins instead of flying leads. This allows the tube to be installed in a common 10-pin socket still being produced in China. Like most VFD tubes, the IV-12 includes a grid that can be negatively charged to interrupt electron flow without disabling the filament. This capability allows for multiplexed operation (see schematic shown below) and effectively turns the tube into a triode.

The IV-17 (“NB-17”) is a medium-sized sixteen-plus-two segment VFD tube manufactured in the Soviet Union by Reflector, known today as Sovtek. Unlike the IV-12 seven-segment tube, the IV-17 can display all letters of the English alphabet in addition to the numbers zero through nine. Sixteen segments are dedicated to displaying characters, while the remaining two are used for the left and right decimal points. The character set used in the photos below is based on the one suggested by the datasheet of the Burroughs B-7971 fourteen-segment Nixie tube.

The 8894 is an early vacuum fluorescent display (VFD) tube manufactured in the united States by Sylvania and sold under the brand name “Flurotron”. Its most distinctive feature is the use of “floating” segments; unlike most other VFDs, where the segments are held on a continuous backplane. Another notable difference from later VFD designs is the absence of a control grid. Because of this, multiplexed driving is not possible, resulting in more complex drive circuitry.