The DG12B is a VFD tube manufactured in Japan by the Itron Corporation, the company that originally invented VFD technology in 1966. What makes this tube stand out in particular is the distinctive appearance of its digits. Rather than using the seven-segment design still commonly found in digital readouts today, it employs a more intricate nine-segment arrangement that gives the digits an almost hand-written look. Among collectors, VFD tubes featuring this design are commonly referred to as “Alien VFDs.”

The GR10K is an early Nixie tube manufactured by ETL in Great Britain sold under the brand name ‘Digitron’. It is identical to the GR10H except for the omission of an anode grid. While this gives the tube a highly unique and appealing appearance with great visibility of the digits, it also means that there is nothing preventing sputter from the cathodes accumulating on the inside of the glass envelope. As this happens, it forms a thin reflective layer which may eventually obstruct visibility entirely. According to its datasheet, the GR10K is a long-life tube and it does emit the characteristic blue-ish light typically associated with the inclusion of mercury vapor. This means that the tube’s effective lifespan under nominal conditions is likely limited more by sputter buildup than by cathode disintegration.

The 6G-E12A is peculiar magic eye tube manufactured by the Japanese company TOYO. Unlike most top-viewing magic eyes tubes, such as the common 6E5, which feature circular screens, the 6G-E12A’s screen is rectangular. It is the successor to the 6G-E12 tube, which features a similar rectangular screen design but has a different display characteristic.

The 6G-E12A is a so-called double indicator tube, meaning it has two independently controlled shadow angles. This allows it to visualize two signals simultanously which made it particularly suitable for FM stereo indication. For simplicity, I connected both channels together in the video shown below.

The HB-105 is a so-called Pixie tube manufactured by Burroughs. Unlike a Nixie tube, which forms numerals from a stack of digit-shaped cathodes, the Pixie tube uses a single anode plate perforated with digit-shaped holes, through which a neon discharge can be seen. The tube’s datasheet lists its various supposed advantages over Nixie tubes which included the ability to display multiple digits simultaneously and its low operating current. Additionally, it was significantly cheaper than conventional Nixie tubes at the time.

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.

The LD-836 is a medium-sized Nixie tube manufacured by NEC in Japan, notable for its highly unusual, nearly rectangular glass envelope. This distinctive shape makes the tube’s front face significantly narrower than that of comparable Nixies and allows multiple tubes to be placed closer together in display assemblies. In addition to displaying the digits 0 through 9, the LD-836 also includes a right-hand decimal point. Its internal design closely resembles that of NEC’s CD66A, sharing a similar wire anode assembly, which leads to significantly improved digit visibility compared to the more typical grid design. The LD-836 is an exceptionally rare Nixie tube, with barely any information being available on it publicly.

The ZIN-70 is a modern Nixie tube and, with its 70mm digits, ranks among the largest ever produced. Handmade in limited quantities by the Ukrainian company Millclock, it is available both as part of their Nixie clock range and as a standalone component. Its construction bears a strong resemblance to another contemporary Nixie tube: the R|Z568M, manufactured by Dalibor Farný and his company. A comparison image below shows the ZIN-70 on the left and the R|Z568M on the right.

The B-5441A is a medium-sized Nixie tube manufactured by Burroughs. What sets this tube apart is the fact that it was evacuated from the bottom, a feature usually only found in larger side-viewing Nixie tubes. This design results in a perfectly dome-shaped top. In addition to displaying digits zero through nine, the B-5441A also includes both left and right decimal points. These distinctive features make it highly sought after by collectors, particularly fans of the popular anime Steins;Gate, who consider its shape ideal for recreating the “Divergence Meter” device featured in the series.

The GA12 is a large Nixie tube distributed by Swiss manufacturer Cerberus, though it was not originally produced by them. Instead, it is a rebranded version of the GR10J tube manufactured by ETL in Great Britain as part of their DIGITRON line of display tubes.

This tube stands out for several reasons. Firstly, it features a copper-colored anode, an unusual characteristic shared by only a handful of other Nixie tubes, such as the XN12. Secondly, the base of the tube is wrapped in black shrinkwrap, concealing the internal electrode connections to both the anode and cathodes. This covering might serve a functional purpose, as occasional discharges can occur at the electrodes themselves, and the shrinkwrap could be intended to hide it in such cases.

The Burroughs B-5092 is a medium-sized Nixie tube that shares pin compatibility with other common top-view types such as the ZM1020, Z560M, and GN-4. Unlike these, however, it features a taller, more slender glass envelope. Its most distinctive element is the unusual anode cage, which leaves the cathode stack clearly visible from the side.

Another detail that can be seen from the side is the so-called “giver pill,” a tiny glass bead that originally held mercury vapor. After the tube was sealed, the pill was heated by running current through the wire it is wrapped in, causing the bead to rupture and release the mercury inside. The presence of mercury helps suppress sputtering, significantly extending the tube’s service life. This long-life characteristic made the B-5092 especially popular for Nixie clocks, though today the tube has become quite rare.

The B6037 is an unusual Nixie tube manufactured by Burroughs, making it an “official” Nixie tube as indicated by the labeling on its glass envelope. Unlike most Nixie tubes, which display only the digits 0–9, the B6037 includes an extra cathode shaped as a “1” placed next to the standard stack of digits. This allows the tube to display numbers from 0 to 19.

Its glass envelope is relatively large to accommodate the two digit stacks, though it still uses the same 15.5 mm characters found in many smaller Nixie tubes. The envelope is also covered with black shrink wrap. Interestingly, the anode grid was apparently not designed specifically for this model. In most tubes, the anode is supported by the same posts that hold the digits, but in this case it has been shifted to the right and is instead held in a somewhat awkward position at the upper right of the tube.

The ZM1070 is a neon-filled, double-pulse decadic counting tube manufactured by Valvo in Germany. It supports bi-directional counting and operates at speeds of up to 5,000 counts per second. Each of its ten stable cathodes is connected to a separate pin, allowing external actions (such as advancing a second stage Dekatron) to be triggered when a specific cathode is active. This design also enables the tube to be reset to any of its ten positions by applying a brief negative pulse to the desired electrode.

This document presents a price list of various common types of Nixie tubes and their corresponding sockets offered by Baird Atomic, effective July 7, 1966. The Nixie tubes were manufactured by National Electronics and distributed by Baird Atomic. Equivalent tubes were sold by National Electronics with the prefix ‘NL’ instead of ‘BA’.

As of July 25, 2025, the cumulative inflation rate of the U.S. dollar since 1966 is approximately 900%. To adjust the listed prices for inflation, multiply each by ten.

The XN10A is a medium-sized symbolic Nixie tube manufactured by Hivac in Great Britain as part of their ‘Numicator’ line of display tubes. It displays a plus sign, minus sign, and sine wave symbol. Its size made it compatible with other numeric tubes in the XN series, such as the XN1, XN3, and XN12. The tube also has the same restrictive anode cage found in the aforementioned tubes, which limits visibility primarily to front-facing angles. Tubes like the XN10A were commonly used in digital multimeters, where the sine wave symbol would have indicated the presence of an AC voltage.

The Z565M is a neon-filled decadic display tube manufactured by RFT in East Germany. Although it resembles a Dekatron, it lacks any kind of counting capability. Unlike the ZM1050/Z550M, it also cannot be controlled using logic-level signals. Instead, it operates more like a regular Nixie tube and is soemtimes referred to as a “Register tube”.

It features ten wire-formed cathodes arranged in a circle around a common anode. One or more cathodes can be ignited by connecting them to ground. When viewed from the front, the tube shows two empty holes between each cathode. In a full Dekatron tube, these positions would have been occupied by the transfer electrodes. To ensure consistent ignition regardless of ambient light or background radiation, the Z565M includes a small amount of radioactive material to improve the rate of spontaneous ionization of the neon gas.

The GN-5A (military code CV5351) is a large top-viewing Nixie tube produced by the British manufacturer STC and marketed under the “Nodistron” brand. It succeeds the GN-1 and GN-2 models, maintaining the same pinout and compatible electrical specifications. A distinguishing feature of the GN-5A is the faint bluish glow emitted by its illuminated digits, indicating the presence of mercury in the gas mixture which was absent from its predecessors. This mercury addition likely contributes to a significantly extended lifespan. Visually, the GN-5A closely resembles the GN-2, with the main external difference being the addition of a non-evaporative getter, a feature commonly found in later-generation Nixie tubes.

The GI-21 is the larger counterpart to the GI-10, both manufactured by National Union as part of their “Inditron” line of display tubes. This places it among the earliest Nixie-style tubes ever produced, even predating the term “Nixie” itself that was coined by Haydu Brothers (later Burroughs) in the late 1950s.

Like the GI-10, the GI-21 does not feature a dedicated anode cage, which became standard in later Nixie tubes. Instead, to illuminate a specific digit, all other digits must be held at anode potential while the desired digit is connected to ground. Interestingly, the GI-21 includes four metal rods connected to one of the pins on its phenolic base. In some examples, such as the one shown below, these rods can function as a dedicated anode, significantly simplifying the required driving circuitry. However, this functionality appears inconsistent across different units, suggesting that it may have been an experimental or partial implementation of a dedicated anode that did not fully meet expectations.

The SZ-8 is a medium-sized Nixie tube manufactured by the Chinese company Zhishiguan (somtimes called Universe). Among the few Nixie tube models produced in China, the SZ-8 is by far the most common. Alongside the Soviet Union, China was one of the last countries to continue manufacturing Nixie tubes in significant quantities into the early 1980s.

Visually and electrically, the SZ-8 resembles European models like the ZM1022 and Z5600M, and it shares the same pin configuration. However, unlike these European counterparts, the SZ-8 has a shorter lifespan due to the absence of mercury vapor in its gas mixture. This omission makes it unsuitable for continuous-use applications such as clocks. Nevertheless, the lack of mercury results in a uniquely vivid and pure orange glow from the digits which partly makes up for the poor internal construction many units exhibit.

The CK8650 is a Nixie tube manufactured by Raytheon in the USA and sold under their “datavue” line as a Numerical Indicator Tube. Compared to other Nixie tubes with similarly sized digits, the CK8650 has a notably short and stubby appearance. Its diamond-shaped anode grid extends significantly beyond the frontmost digit, giving the tube a distinctive look. Not visible to the camera, glowing digits are surrounded by the characteristic blueish haze typically associated with the inclusion of mercury vapor which greatly extends the lifespan of Nixie tubes. The tube uses a standard 9-pin Noval base, along with two additional pins in the center, providing just enough connections to display digits 0 through 9, but lacking any decimal points.

The XN3 is a medium-sized Nixie tube manufactured by Hivac in Great Britain and Lorenz in Germany and part of their ‘Numicator’ line of display tubes. According to its datasheet, it is the direct successor to the XN1, featuring pin compatibility and primarily differing in its increased lifespan. Unlike many later long-life tubes, however, the XN3’s discharge does not exhibit the characteristic bluish glow associated with mercury vapor. The XN3 also lacks the evaporative getter present in some XN1 units; instead, it uses a more conventional, non-evaporative getter positioned at the tube’s top, typical of Nixie tubes. Like the XN1, its anode cage restricts digit visibility, making the display primarily readable from straight-on viewing angles. In addition to the transparent version shown below, a variant coated in a red filter was also produced.

The 6ME5 (also known as 6M-E5) is a miniature magic eye tube manufactured by TOYO in Japan. It closely resembles the common 6E5 tube, but in a smaller form factor. It features the same basic display characteristic of a single shadow that opens or closes according to the supplied input voltage. The tube requires a relatively low target voltage of only 180V (opposed to the 250V typical for most magic eyes), the closely related 6ME10 even just 100V.

The CD11 is a medium-sized, top-viewing Nixie tube produced by the Japanese manufacturer Rodan Okaya. It serves as the direct successor to the GR-201 and maintains identical pinouts and electrical specifications. Like other Rodan tubes, the CD11 features a sleek, chrome-plated base with a gold-colored sticker displaying the manufacturer’s logo and the tube’s model number.

In keeping with Rodan’s signature style, the CD11 features an exceptionally elegant digit design and emits a pure, vibrant orange glow. Each tube was originally packaged with a compatible socket included.

The GR10G (also known as CV8090) is a large Nixie tube produced by the British manufacturer ETL. It stands out due to its unconventional design: notably, it lacks a solid back plate on the anode cage, allowing the digits to be viewed clearly even from behind the tube.

Its unusual characteristics extend to its electrical specifications. According to the datasheet, the recommended supply voltage is at least 220V, with an internal voltage drop of approximately 180V across the ionizing tube. Furthermore, the recommended minimum operating current of 6mA is higher than typical for Nixie tubes of similar size. Its gas mixture does not appear to contain mercury vapor, which likely contributes to its poor average lifespan rating of only 5000 hours. This short lifespan restricts its practical use in many projects, despite its distinctive visual appeal.

The ZM1040 is a large Nixie tube produced by various European manufacturers, with this particular unit made by Valvo. Tesla, a Czechoslovakian manufacturer, produced a version of the ZM1040 that featured a square anode grid, setting it apart from the one shown here. To enhance contrast and filter out blue light emitted by the included mercury vapor, the tube is covered with a red filter. A variant without this filter was also available under the designation ZM1042.

The DGM01 is a modern Nixie tube produced by Sadudu and his company iNixie LAB in China, comparable in size to the Soviet IN-18. Like the R|Z568M by Dalibor Farný, the DGM01 is assembled by hand in small quantities. Each digit in the tube has a distinctive design, with the numbers one and five standing out in particular. Notably, the DGM01 features a right decimal point which is unusual for tubes of this size and was specifically incorporated for use in replicas of the Divergence Meter from the popular anime series Steins;Gate. Unlike the R|Z568M and tubes made by Millclock, which have a large metal bases, the DGM01 utilizes proper pin-to-glass seals, enhancing its authentic appearance. The glow discharge exhibits the characteristic blue tint seen in tubes containing mercury vapor, which is indicative of long-life Nixie tubes.

The CD66A, produced by NEC in Japan, is a medium-sized Nixie tube capable of displaying all ten digits along with a right decimal point. It features a distinctive anode design made up of multiple horizontal wires, differing from the typical hexagonal or square grids stamped from sheet metal in most Nixie tubes. A variant of the CD66 with a left decimal point was also available. In Europe, the CD66 was sold as the ZM1242.

The B-7971 is a very large neon-filled alphanumeric display tube manufactured by Burroughs. Unlike ordinary Nixie tubes, which contain cathodes in the shape of symbols arranged on a stack, the B-7971 features 14 individual wire segments that can be combined to display every letter of the English alphabet in addition to digits 0 through 9. An additional segment in the bottom can be used to display an underscore. As opposed to the typical 16 segments found in most alphanumeric displays, the B-7971 only has a single segment in the top and bottom of the display area.

The N4 is a neon-filled decadic counting tube manufactured by the German company DGL Pressler (Deutsche Glimmlampen GmbH), which is mostly known for making discharge tubes and phototubes. The tube operates in a unidirectional, single-pulse mode and each of its ten stable cathodes is accessible externally via a separate pin. According to its datasheet, the N4 is capable of up to 25,000 counts per second, making it exceptionally fast for a neon-filled Dekatron.

The GC12/4B is a neon-filled counting tube manufactured by ETL in Great Britain. It is capable of bi-directional operation at up to 4,000 counts per second. It features twelve stable cathodes, unlike the usual ten found in most Dekatrons, which allowed it to be used for base-12 counting. Four of these cathodes are accessible via output pins, enabling them to trigger actions such as advancing another Dekatron when active. Divide-by-12 Dekatrons like the GC12/4B were ideal for timekeeping applications since the division of hours, minutes, and seconds in a day aligns with multiples of twelve.

This document released by Mullard explains the operating principles of glow discharge tubes and their internal construction. Additionally, it includes schematics for various applications, beginning with a simple static display and progressing to two different approaches for implementing a multiplexed display. In addition to describing the anode-scanning method, which is the most widely used approach today, it also presents an alternative cathode-scanning technique and discusses the various drawbacks associated with this method.

The XN1 is an early Nixie tube produced by Hivac in Great Britain and Lorenz in Germany. The earliest documentation referencing this tube I could find is dated September 9, 1961, shortly after the invention of Nixie tubes. This particular unit features an evaporative getter at the top, giving it a distinctive appearance typically associated with vacuum tubes (often seen in VFDs). However, versions with a getter located behind the anode cage were also manufactured. The tube’s anode cage is notably restrictive, limiting visibility to mostly straight-on angles. Unlike many other tubes of similar size, the XN1 does not include any decimal points.

The E1T is a decadic counting tube developed by Philips which predates the invention of gas-filled Dekatrons. Each pulse advances the tube’s internal count by one and generates a voltage spike, which can be used to trigger external actions such as advancing the next stage of a multi-tube counter. Internally, the E1T operates as a small cathode ray tube with a ribbon-shaped electron beam that occupies one of ten stable positions. The current position of the beam is indicated as a glowing strip, with each position marked with its corresponding value on a piece of film affixed to the tube’s glass envelope. The tube’s envelope is coated with a transparent protective layer, which is prone to cracking over time, particularly in damp environments. Consequently, E1Ts in pristine condition have become increasingly rare.

The DR2010 is a Numitron display tube developed by RCA. It is identical to the DR2000 except for the latter lacking a decimal point. As shown below, some units feature a flat top, while others have a convex top. This seems to be a manufacturing variation and does not necessarily correspond with different model numbers.

This series of Numitrons is renowned for its exceptional reliability and has a rated lifespan of at least 100,000 hours. Longevity can be further extended by operating the tubes at reduced currents and maintaining a small current through inactive filaments to minimize thermal cycling. Since Numitrons emit a wide spectrum of light, color filters can be used to change their color.

With its 40mm digits, the IN-18 (“NH-18”) is the largest Nixie tube mass-manufactured in the Soviet Union. It shares the same envelope diameter with smaller Nixie tubes, such as the ZM1040 and Z566M, which gives the IN-18’s digits a slightly elongated appearance. Today, the IN-18 is among the most popular Nixie tubes, often used in large Nixie clocks. Although vast quantities were manufactured and remain readily available on online marketplaces like eBay, IN-18 tubes have become quite expensive. Unlike many Soviet Nixie tubes, the IN-18 features a proper cathode for the number five rather than an inverted two. Its gas mixture includes trace amounts of mercury vapor, which significantly extends the tube’s lifespan and imparts a faint bluish tint to its glow.

The IN-1 (“NH-1”) is the first generation of Nixie tube mass-produced in the Soviet Union. Like some other Soviet Nixie tubes, the IN-1 utilizes an inverted two to represent the number five, although at least some earlier models featured a proper five. This tube is notable for its large phenolic base, with each pin conveniently numbered. As is typical of early Nixie tube designs, the IN-1’s gas mixture lacks mercury vapor, which results in a relatively poor lifespan. It is, however, pin-compatible with and visually very similar to the Polish Dolam LC-516, which could be considered as a longer-lasting alternative for those who appreciate the IN-1’s UFO-like design. Original U11 sockets are notoriously difficult to come by so building a device using either of them would likely require coming up with a custom made socket design.

The GN-2 is a large Nixie tube produced by STC as part of their ‘Nodistron’ line of display tubes. It is pin-compatible with and the direct successor to the GN-1 and already shows notable advancements in Nixie tube manufacturing. Unlike its predecessor, the GN-2 features digits stamped from sheet metal instead of ones made from bent wire. These digits are arranged in a more compact stack, separated by insulating rings. The thick wires previously used to connect the numerals to their corresponding pins have been replaced with the thinner leads seen in most later top-viewing Nixie tubes. Additionally, the GN-2 no longer employs evaporative getters and the pin connected to the anode meant for operation with rectified AC voltage on the GN-1 is now marked as NC in the tube’s datasheet. The tube’s numerals emit the same distinctive orange glow seen in the GN-1, indicative of a mercury-free production process suggesting a relatively short operational lifespan.

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 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 6E5 is one of the earliest examples of a magic eye tube, which were invented in 1932 by American electrical engineer Alan DuMont. They were designed as a cost-effective alternative to expensive needle indicators and were intended mostly for use in consumer devices such as radios that required user tuning without high precision. The first commercially available 6E5 tubes were made by RCA starting in 1935 and featured a coke-bottle-shaped glass envelope common in early vacuum tubes.

The GR-211 is a large Nixie tube produced by Rodan-Okaya in Japan. It ranks as the third-largest Nixie tube made by Rodan and succeeded the short-lived GR-11. Later models were rebranded as CD94. Notably, the GR-211 includes a left decimal point, which is uncommon for tubes of its size. In devices using larger Nixie tubes, a separate neon bulb typically represented the comma instead. Interestingly, the datasheet marks the decimal point’s pin as “not connected.”

The Tesla 11TU7 is a neon-filled Nomotron counting tube capable of up to 20,000 counts/second. It operates in a unidirectional, single-pulse mode, advancing the discharge by one position with each pulse and featuring ten stable positions. Unlike conventional decadic counting tubes (Dekatrons), its guiding electrodes are concealed behind a metal shell. Only the ten stable cathodes are visible through circular openings, each marked with its corresponding value on a transparent mica shield.

The R|Z568M is a massive modern Nixie tube produced by Dalibor Farný and his company. Each tube is manufactured by hand in the Czech Republic. As the name suggests, its design is meant to be reminiscent of the Z568M, the largest Nixie tube produced in the GDR. A picture below shows a comparison between the R|Z568M, an original Z568M, and a Z566M. Despite being the smallest of the three, the Z566M, with its 30mm digit height, is still considered a large tube. This makes the impressive scale of the R|Z568M, featuring 50mm digits, even more striking. The manufacturing process of an R|Z568M tube is documented in this video.

The DTF104B is a Numitron display tube developed by RCA. Internally, it is nearly identical to the more common DR2000 and similar to the DR2010, but it is designed to be read from the top rather than the side. A spot exists on the backplate where a left decimal point could have been included, but it lacks filaments and is therefore non-functional on this model. Its flat top gives the DTF104B a distinct look and helps reducing reflections from adjacent tubes.

This document provides information on STC’s GN-1 Nixie tube. It includes a datasheet outlining the electrical specifications for both DC and rectified AC operation, as well as mechanical details such as tube dimensions and digit height. Additionally, it features circuit diagrams illustrating how the tube can be used in conjunction with the G10/241E counting tube. This document describes a very early version of the GN-1 without an anode grid. Later units included one, likely to achieve more even illumination.

When the Nixie tube was introduced in the 1950s, it faced a significant drawback: its driving circuitry required transistors with relatively high breakdown voltages capable of handling the elevated operating voltages necessary to drive them. At the time, such transistors were not readily available. This limitation created a demand for an alternative display technology that could be operated with low-voltage, low-current logic circuitry. The solution was the Z550M, which was later renamed to ZM1050.

The Z566M is a large Nixie tube manufactured by RFT. It is pin compatible with the ZM1040 but differs in design, featuring a flatter top and a top-evacuation design, though some earlier units were evacuated from the bottom. In some instances, Z566Ms have even been rebranded and sold as ZM1040s (see picture at the end of this page). A variant without the pre-applied red filter was marketed as the Z5660M.

The Z566M was primarily utilized in laboratory equipment such as voltmeters and frequency counters. Its large size also made it well-suited for devices designed for use in educational settings, such as schools. A Nixie tube featuring various symbols, designed to complement the Z566M/Z5660M, was marketed under the names Z567M and Z5670M.

The MG-19B is a tiny, segmented neon-filled display tube produced by Rodan and marketed under the Elfin brand, designed for use in small electronic instruments. It features two additional diagonal segments, enabling it to display the digits ‘1’ and ‘7’ more naturally, as well as certain other alphanumeric characters. The tube also includes a right decimal point. Unlike Nixie tubes, each cathode in the MG-19B requires an individual resistor, as the current needed varies with the number of illuminated segments. With a 180V breakdown voltage and a recommended 230V anode voltage, the tube operates at significantly higher voltages than most Nixie tubes. This made driving the MG-19B more complex, as affordable high-voltage transistors were not readily available when the tube was introduced.

This document details the design, functionality, and application of the STC G10-241E Nomotron, a unidirectional single pulse counting and display tube. It describes its operation and highlights its applications in areas such as tachometry, counting and batching, and frequency and time measurement. Besides a general overview over its mechanism of operation, it also contains detailed diagrams of the tube and example circuits for many of its aforementioned use cases.

Detail pictures of the G10/241E can be found here.

The LC-516, produced by Polish tube manufacturer Dolam (later known as Unitra Dolam), is pin-compatible with and visually similar to the Soviet IN-1 Nixie tube. However, unlike the IN-1, an early model with a relatively short lifespan, the LC-516 contains small amounts of mercury, which significantly improves its longevity and gives its discharge a subtle bluish tint. The LC-516 features a slightly smaller glass envelope and digits compared to the IN-1; a comparison between the two is shown below. Notably, the LC-516 has a black base, which is also found in IN-1s intended for export. Dolam also manufactured a version without the phenolic base under the designation LC-513.

The National Union GI-10 is likely the first Nixie tube ever produced, belonging to National Union’s Inditron series of display tubes. Patented applied for in 1954 (and granted in 1956), it predates the original “NIXI” tube developed by Haydu Brothers and later Burroughs by at least a few months. Similar to other early Nixie tubes, such as the STC GN-1, its digits are not stamped from sheet metal but are crafted from wire. These digits are connected to the tube’s 10 pins via long rods covered in an insulating layer of ceramic that also serve to hold them in place. In contrast to more modern Nixie tubes, where the digits are arranged to minimize obstruction of each other, the digits in the GI-10 are organized in a straightforward, sequential manner. The zero digit is positioned at the very front, while the one is located at the farthest point in the stack. Unlike most later Nixie designs, the GI-10 lacks a dedicated anode; instead, activating a specific digit requires all other electrodes to be held at anode potential, which complicates the driving circuitry and makes it difficult to achieve uniform brightness across all digits. The tube uses a standard Noval 9-pin socket with an additional central pin.

English title: Notes on the use of indicator tubes

This document contains information on various East German display tubes and examines their respective areas of application as well as their advantages and disadvantages. In particular, the different operating modes of Nixie tubes are discussed. At the end of the document the technical data of some common Nixie tubes can be found.

The content of the booklet differs from that of the similarly titled “Hinweise zur Anwendung von Anzeigeröhren - Sonderausgabe 3/1968”.

English title: Notes on the use of indicator tubes - Special issue 3/1968

This document contains an excerpt from the magazine “radio und fernsehen” (“radio and television”), published in the GDR, which discusses the use of various East German display tubes, with a particular focus on the Z570M and Z870M. It was released by RFT in March 1968.

The content of the booklet differs from that of the similarly titled “Hinweise zur Anwendung von Anzeigeröhren”.

The GR10H is an early Nixie tube produced by ETL, featuring digits visible through a small viewing window, with the majority of its envelope coated in black paint, likely intended to enhance contrast and minimize light bleed from adjacent tubes. Shown at the end of this page is a transparent GR10H revealing that, like in the STC GN-1, the digits are connected to the tube’s pins via thick wires and an evaporative getter was used.

The G10/241E is a neon-filled Nomotron made by the British manufacturer STC and capable of speeds of up to 20,000 counts/second. It operates in a unidirectional, single-pulse mode, advancing the discharge by one position with each pulse and featuring ten stable positions. Unlike conventional decadic counting tubes (Dekatrons), its guiding electrodes are concealed behind a metal shell. Only the ten stable cathodes are visible through circular openings, each marked with its corresponding value on a transparent mica shield.

The SAO M 40 is a so-called Sphericular Optic Display sold by OmniRay. Although similar in both appearance and application to projection displays such as the one-plane readouts sold by IEE, the underlying theory of operation is vastly differemnt.

A projection display contains a matrix of small light bulbs that can be turned on and off individually, with each bulb responsible for producing a specific character, usually a digit, on the readout screen. A character is thus selected by turning on its respective light bulb, which shines through a mask with a cutout in the appropriate shape. The light is then deflected by a specially shaped lens assembly, focused, and projected onto the back of the diffusion screen, creating a character visible from the front.

The GN-1 (also known as G10/201E) was among the earliest commercially available Nixie tubes. It was manufactured by the British company STC and sold under their brand name “Nodistron.” The oldest piece of documentation on the tube I could find is the original STC datasheet linked below, which is dated 1959. This places the tube towards the very beginning of Nixie tube manufacturing.

The tube’s age is reflected in its design and construction. Unlike virtually all Nixie tubes manufactured later, the digits on the GN-1, which are also quite large for a top viewing tube, are not stamped from sheet metal but are formed from pieces of wire that have been bent into the shape of digits. Furthermore, they are not arranged on a rod and separated from one another by insulators, but are mounted directly between two mica shields enclosing the anode cage at the top and bottom. The discharge surrounding them when active exhibits the characteristic orange glow typically associated with mercury-free neon fillings, which greatly limited the effective lifespan of early Nixie tubes. Other interesting features include the use of braided cables, which connects two of the tube’s cathodes to their respective pins, and the two evaporative getters clearly visible on the left and right sides of the glass envelope. Finally, the tube’s rugged base is partly made of sheet metal, which, while not unusual for early vacuum tubes, is very rare in Nixie tubes.