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| Nixie & Gas Discharge Displays |
Gas discharge displays are low pressure neon lamps with multiple, shaped or shape-shaded cathodes. Tubes in this family include Nixie, Pixie and Panaplex displays, as well as more exotic technologies like gas thyratron and Self-Scan displays. |
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| Burroughs 4021L & 7977 | |
Devices included in this entry: A related device is the Burroughs 7977 Nixie tube, which has an identical internal construction and envelope to the 4021, but is encased in a black silicone sleeve to reduce back-lighting of the displayed digit. The 7977 is designed to be used with a socket, and lacks the flying leads of the 4021L. |  |
| Burroughs B4998 | |
The Burroughs B4998 is the smallest Nixie tube ever mass produced, it's tiny elliptical envelope is only 15mm high and 10mm wide. The B4998 contains the same 8mm digits as the 4021L tube shown above, but the elliptical envelope reduces the overall size of the tube and allows for tighter side-by-side installation of multiple digit displays. B4998 nixie tubes are highly coveted among modern hobbyists for use in construction of 'Nixie watches' and other tiny Nixie displays. Ironically, the integrated driver modules provided by Burroughs for use with the B4998 are much bulkier than those manufactured for it's larger tubes. |  |
| Rodan Elfin MG-17F & MG-17G | |
The MG-17F represents a point of transitional evolution for neon displays; a short lived period where manufacturers began to switch to flat segmented displays, but still packaged them in tubular envelopes. Unlike other Nixie tubes, the MG-17F does not have stacks of shaped cathodes to form it's digits. Instead simple bar cathodes are arranged to form a seven segment pattern. This tube has upper and lower decimal points, allowing it to be mounted normally or with the leads exiting the top of the envelope. Despite being a transitional device, the MG-17F saw use in a number of consumer products, most likely due to lower manufacturing costs when compared to competing stacked cathode Nixie tubes. Rodan also produced the MG-17G, a variant of this tube with smaller digits and only a single decimal point. The MG17-G lacks the front anode screen present in the MG-17F, resulting in a brighter and more visible display. The MG-17F and MG-17G were both released in 1969, and competed directly with first generation LED displays like the Monsanto MAN1. |  |
| Rodan MG-19B | |
The Rodan MG-19B is a small segmented nixie display, likely intended for use in calculators. Produced in Japan, the MG-19B was sold under the Elfin trade name in the US. The tube's most noteworthy feature is the inclusion of two additional diagonal segment in the middle of the tube, which allows for the display of a more pleasing '7' character as well as several additional alphanumeric symbols. Each of the diagonal segments is brought out to a separate pin on the base, allowing them to be controlled individually. Digit height on this tube is 11mm and the entire envelope is 49mm long including the nipple. Unlike it's close neon display relative, the MG-17F, the MG-19B has only a single lower decimal point, which makes the tube a poor choice for inverse mounting. The example shown here is an Alco branded variant of this tube. The MG-19B appears to have been sold by several different manufacturers. |  |
| Burroughs B7971 | |
The large and unwieldy Burroughs 7971 is the iconic example of an alphanumeric Nixie tube. The display contains a series of wire cathodes arranged into an array of 15 segments and an underscore character, unlike modern 17-segment LED displays, the top and bottom vanes have been ganged together on a single control line. Despite their staggeringly high price on the resale market, 7971's are a relatively common tube, the tube's large size and high functionality have made it the display choice for nixie projects and demand has increased accordingly. In the time before the Nixie clock craze, 7971's could regularly be bought from electronics suppliers for less than a dollar per tube. Despite electronics lore to the contrary, 7971 nixie tubes were never used in the marquee at the New York Stock Exchange. The primary (possibly only) commercial use for the 7971 is in Ultronic Letrascan stock tickers, which collectively generated sales for hundreds of thousands of tubes. The Lectrascan display contained a staggering 48 7971 display tubes, along with a veritable hardware store of transistors and other discrete driver circuitry. |  |
| 8422 / CK8422 Series | |
Devices included in this entry: Raytheon also made a symbol tube companion to the CK8422, the CK1903. This tube displays plus and minus symbols and has a special reduced size anode mesh to match the size of the digit stack. |  |
| Burroughs B5971 | |
Devices included in this entry: |  |
| Burroughs HB-105 | |
The problem with Nixie tubes, both in the 1960s and now, is that they are simply far too expensive. Pixie tubes are a curious technological dead-end, an attempt by Burroughs to make a cheaper, more affordable gas discharge display. Instead of having a series of shaped cathodes for each digit, a Pixie tube has a single shaped anode with number shaped holes over each of the pins in the stamped glass base. Stub cathodes are attached to the top of each pin, which glow through the holes in the anode during operation to indicate a numeric value. Pixie tubes cost only about a quarter as much to manufacture as a Nixie tube of similar size. The low cost did not win over users however, a Pixie tube produces a remarkably tiny and unreadable display, and most early Nixie tubes were used in equipment costing many multiples of thousands of dollars where the expense of the display could be justified. Nobody knows what the first Pixie tube part number is, but given the HB105's Haydu part number and ridiculous oversized envelope, it is definitely an early example. Ironically, Pixie tubes are now quite a bit more expensive than the Nixie tubes they were originally designed to undercut; they are quite popular among electronics hobbyists for making clocks and other novelty items. Burroughs originally marketed the tube's ability to be controlled by a five volt differential in an attempt to make the tubes seem more 'transistor friendly', but modern hobbyists typically drive them with standard Nixie circuits instead. |  |
| Burroughs B9012 | |
The B9012 pixie tube, made by Burroughs, is the replacement for the short-lived HB-105. The B9012 has the same display face as the HB-105 and uses the same obscure double-ring 13 pin base, but has a long life mercury doped fill gas and more refined internal construction. The tube dispenses with the high domed envelope of the HB105 and replaces it with a more conventional envelope that only has a height of 20mm. While still rare, the B9012 is not pure unobtainium like the HB-105, and its long life makes it the obvious choice for any sort of Nixie clock-style electronics project. Variations were made with both blue and black print. |  |
| Phillips Z550 | |
The Z550 is a pixie tube with a twist, it is a display that includes its own switching thyratrons for easy control from a 5 volt TTL signal. Each digit contains a small starter electrode that pierces a ring anode and cathode plates to poke into the cavity behind the digit stamp. By controlling the voltages present on the anode and cathode, it is possible to put the tube in a state where a mere five volt pulse on the starter electrode will trigger the glow discharge for the selected digit. The entire display assembly is constructed on a thick glass billet which is then sealed in the tube's 13 pin envelope; unlike the Burroughs HB-105 and 9012, the Z550 envelope is relatively devoid of empty space. As with the Burroughs pixie tubes discussed above, the 5 volt control scheme is almost never used by modern experimenters, who typically use a traditional Nixie control system connected to the tube's starter electrodes instead. It should be noted that all Z550 tubes were made by Phillips in their Eindhoven plant, regardless of the manufacturer's stamp. Z550 tubes were restamped near the time of sale to match the nameplate for the target country. |  |
| Burroughs HB-106 | |
The HB-106, as indicated by its Haydu part number, is an early model of Burroughs top view nixie tube. Burroughs parts which were manufactured at the Haydu plant begin with the "HB" prefix; Burroughs only made use of the Haydu brand name for a short amount of time, and later part numbers were prefixed with a "B" instead. This tube has a silicone surround that is integral to the part and was designed to increase readability in high brightness conditions. The part number is printed on a plastic wrapper affixed to the surround. Unfortunately, as this example shows, the plastic wrapper is just as prone to disintegration as the water soluble paint used on most other models of tubes. |  |
| National Union GI-10 Inditron | |
The GI-10 'Inditron' is an historical curiosity, a Nixie-style numerical indicator tube which was developed in parallel to the more successful Burroughs Nixie, and may actually predate the Burroughs Nixie by as much as a year. Beginning in 1954, National Union produced a small number of neon-filled indicator tubes which used bent wire cathodes to indicate a numeric value. The tubes had very short operational lifespans and were difficult to drive with the then existing technology, which prevented widespread use and ultimately doomed the tube to failure in the market. |  |
| Philips ZM1000 | |
The ZM1000 is a common, European model of Nixie tube, which was used in a number of different products. This tube's most notable feature is its unusual white glass base, which is equipped with a non-standard gird-shaped array of pins. This strange base serves a purpose; most tubes will fail if their pins are heated with a soldering iron, but the ZM1000 can withstand being directly soldered to a printed circuit board due to its unusual base design. Sockets were also produced for ZM1000, allowing it to be mounted in a more traditional fashion. The tube is otherwise fairly conventional in construction, and has a digit height of 14mm and a total height of 50mm. The ZM1000 was produced by multiple manufacturers in Europe, including Philips and Amperex. |  |
| Philips ZM1010 | |
The Philips ZM1010 is a mundane side view Nixie tube with an unusual feature; a cylindrical anode screen. Unlike most other Nixies, the ZM1010 does not have an opaque backing or mica sheet at the top of the tube, the anode mesh is a cylinder that surrounds the digits on all sides. This give the tube an exceptional 360 degree viewing angle, a useful trait for modern Nixie clocks which typically feature fully exposed tubes mounted to a slab-shaped case. The ZM1010 contains a standard decimal numeric character set and also has a left-side decimal point. Digit height is 14mm and the tube envelope is 18mm in diameter and 32mm high, not including nipple or pins. The ZM1010 uses the same specialized temperature-resistant base as the ZM1000, and is designed to be soldered directly to a printed circuit board. |  |
| Philips ZM1015 | |
The ZM1015 is an uncommon special purpose Nixie tube produced by Phillips for the European market. Built around the same envelope as a Philips ZM1000, the ZM1015 contains digit cathodes shaped into an unusual 'OCR'-style character font. The unusual display font, combined with a circular anode cage, make this a very visually attractive tube, if not a particularly useful one. The tube has the same white glass wafer base as the ZM1000, but unfortunately only displays digits from zero to eight, the other pins are unused and unconnected. The lack of a '9' and '0' character is an unfortunate decision on the part of Phillips, as home builders who wish to make use of this tube's unusual font in their projects will face serious design issues in dealing with the lack of a full character set. Electronics lore has that the ZM1015 was originally produced as a channel indicator for satellite television receivers. Special thanks to Audrey Stroud for providing this unusual part. |  |
| Sperry SP-152 & SP-353 Series | |
Devices included in this entry: |  |
| Sperry SP-332 & SP-333 Series | |
Devices included in this entry: |  |
| Beckman SP-450 Panaplex Display | |
This late model panaplex display shows many of the manufacturing changes that Beckman and others made to their designs as panaplex manufacturing techniques matured. Instead of using the black glass "bathtub" style envelope seen on earlier displays, the SP-450 uses a glass sandwich which is almost identical to the package seen on early LCD displays. All of the leads exit along the edge of the envelope instead of out of the back, and no provision is provided to socket the display for easy replacement. The display itself is 6 digit 7 segment with decimal points. There are also twelve triangular indicators on the sides of the display, normally the small triangle shaped cathodes inside of such a display are intended to be used as "keepalive" electrodes for faster striking, but the location of these cathodes in the package suggests that they may be intended for actual information display. |  |
| Burroughs C6016 Circular Panaplex | |
Though nearly every flat-package neon display ever made is rectangular, circular Panaplexes are apparently a real thing that actually exists in a non-imaginary world, and they get very strange. The C6016, made by Burroughs, is a circular Panaplex that can display both numeric data and directional magnitude on a set of four self-scan bargraph displays. A self scan display is a glow transfer device that functions similarly to a dekatron tube, in which an area of ionized neon gas is bumped along a series of rails in discrete increments. Each bar in the display is linked up to a sequential series of guides, by sending overlapping square waves to each guide, the illuminated section can be pushed up or down the bargraph. Unlike a dekatron tube, which typically contains only two or three guides, the bargraphs in the C6016 are built around 4 guides, which makes them incompatible with common dekatron drive circuits. The C6016 also contains two three-digit displays, which are controlled in a more conventional manner using multiplexed anodes printed on the front glass of the display. With all four of its bargraphs lit, the C6016 looks less like a real device and more like an alien artifact from science-fiction fantasy. Connections to the C6016 are made with a series of right-angle leads that enter the envelope around the circumference of the display. The example shown here was intended for use in a piece of navigation equipment, and the display has been soldered to a carrier PCB with normal pin headers for this purpose. The C6016 appears to have been produced rather late into the era in which Panaplexes were commercially viable; the device shown here was manufactured in 1977. |  |
| Melz ITM2M | |
The ITM2M (also sometimes called the ITM2-M) is a strange device, a Soviet-manufactured indirect gas discharge display. Like a Nixie, the ITM2M is filled with low pressure ionizing gas, but all similarities to more common displays end there. ITM2M tubes contain an array of 16 tiny thyratrons, each painted with one of four colored phosphors. Activating one of the thyratrons causes the gas within to ionize, resulting in illumination of the associated phosphor. These tubes have complex power supply requirements and must be supplied with separate -300VDC, 150VDC, and 75VDC signals to function properly. However, once those needs are met, individual rows and columns are self-latching and can be controlled with a low voltage 10VDC signal due to the switching action of the internal thyratrons.The ITM2M is packaged in a tiny cubical envelope, allowing for the construction of large tiled displays. |  |
| Melz ITS1A | |
Another very unusual Soviet tube, the ITS1A is an indirect gas discharge display configured for seven-segment number generation. Despite appearances the ITS1A is closer to a Nixie tube than a VFD; the device contains seven gas thyratrons, one for each segment, which are painted with green phosphor. When the tube is energized with a high voltage source and a given thyratron is triggered, the neon fill gas will ionize and excite the phosphor in the triggered segment, producing a piercing green glow. As with the ITM2M display shown above, these tubes have complex power supply requirements and must be supplied with separate -300VDC, 100VDC, and 50VDC signals to function properly. Once these needs are met the tube can be controlled with a 5VDC signal, resulting in a neon display that can be directly attached to a microcontroller with no intermediate hardware. The ITS1A is also self-latching, which eliminates the need to multiplex large displays. Related: An ITS1A 'Thyratron' Clock Project |  |
| Beckman SP-450 Alphanumeric Variant | |
Beckman produced a number of late-era, flat packed panaplex displays with the SP-450 part number, all of which have a similar construction style but differ dramatically in layout. This SP-450 variant is particularly large, and is equipped with 32 alphanumeric characters arranged in two rows. A small evacuation nipple is present on the back of the the display from the pumpdown and neon-filling process, but all other connections exit the sides of the display along the sealing seam. These connections are a combination of printed conductive traces and spring loaded leads, the latter of which are fused to the display with a bead of solidified frit. This display is so large that the manufacturer had to include four internal glass pillars between the two rows of characters for added structural support. |  |
| Plasma Display Panel Prototype | |
It is often forgotten that a branch of the Nixie tube family tree terminates in a modern day consumer product; the flat panel plasma TV. The link between these two outwardly disparate devices is the cold cathode plasma display panel, or PDP. A plasma display panel is in effect, a flat 'Nixie' tube; crossed wire cathodes in a glass neon filled envelope result in a device that can display both text and graphics on a matrix of neon pixels. The first plasma display panel prototype was produced in 1966 by researchers at the University of Illinois, and as could be expected was a crude device by any standards. With a resolution of only 4x4 pixels and a package made from plate glass and vacuum epoxy, the University of Illinois prototype could only display a single character. It was not until 1971 that the first viable plasma bitmap product, a 512x512 panel produced for the PLATO computer system, entered the market. The unidentified example shown here, made in 1972, is likely a prototype or short run product due to it's somewhat crude construction. Sadly this example has a broken nipple and no longer functions, though the soft-seal epoxy bonding the two glass plates together would have likely failed even if the tube was otherwise intact. We are unsure as to the manufacturer of this display, but suspect it was made by Fujitsu due to its construction style. Overall, this display is small, ugly, and low resolution, but in a world without liquid crystal panels, it was the only game in town. |  |
| Pantek NCR08501 | |
It is hard to think of a time when VFDs would have commanded such a premium over neon-filled Panaplex displays that a manufacturer would actually try to paint a Panaplex display to make it look more like a VFD, yet the NCR08501 is just such a boondoggle device. Every one of the NCR08501's eight digits has been painted with a white stencil, to trick the user into thinking they are looking at a VFD. Make no mistake though, the NCR08501 is a Panaplex device, it is filled with neon, it lacks filaments and control grids, and the digits light up with an orange gas discharge. The display has 84 pins and is quite large; much of the display's surface area is taken up by the illuminated arrows that ring the numeric portion of the display. Though the display panels are welded together with a fritted glass barrier that should be nearly indestructible, the evacuation nipple appears to soft-sealed with nothing more than a blob of epoxy. This example still has it's original fill gas, but soft-seal epoxy is notoriously failure prone; it is unknown how much extended use such a display could endure. |  |
| Babcock SP-101 | |
The SP-101 is a large single digit bathtub panaplex, one of only a handful of single digit panaplex models that was produced in any quantity. Alternately manufactured by Sperry, Beckman, and Babcock, the SP-101 has a digit height of 25mm, about twice that of the industry standard SP-352. The SP-101 also has colon separators, an uncommon feature for bathtub panaplexes, which makes this an ideal display for a clock projects. This display saw use in survey and construction equipment as well as other outdoor applications, where its large size and sunlight readability gave it a distinct advantage even well after the introduction of LEDs. A common accessory, custom fitted heater coils, were used to prevent the display from freezing in cold weather. |  |
| ETL GR10A | |
Though it resembles a dekatron, the GR10A is actually a register tube - basically a Nixie or Pixie tube shaped like a dekatron. Register tubes were designed to provide a consistent display when dekatrons were used in conjunction with beam switching tubes or hard valve decades in the same counter. The visible glow extinguishes above ~50 kHz, and reappears at lower speeds. |  |
| NEO5000 Gas Discharge Display (Unknown Mfr.) | |
The NEO-5000 (also sometimes called the NEO5000), is a neon-filled seven segment display in a flat, 'Panaplex'-style glass planar envelope. This display is quite large; digit height is 50mm and the tube envelope is 84mm tall. The NEO-5000 uses fairly modern construction techniques; the envelope is made of a glass plate sandwich with fritted seals and epoxied leads. Lifespan is rated at about 35,000 hours, which, while much better than various 'short life' early nixie tubes, is shorter than many other gas discharge displays. Special care should be taken with this display's exposed top nipple, which is quite fragile and easily broken. |  |
| Soviet Anod IN-1 | |
The IN-1 is a large Soviet nixie tube with an end-view envelope and phenolic base. The IN-1, unlike most other gas discharge displays, does not contain any mercury in it's fill gas, which substantially shortens the tube's lifespan. Under normal conditions, the number cathodes in an IN-1 will completely dissolve after only a few thousand hours of operation. The IN-1 is a larger nixie; digit height is 12mm and the tube has a diameter of 30mm and a height of 60mm. The tube's unusual 11 pin phenolic base is practically impossible to find a socket for, though the truly desperate can repurpose Molex pins from an ATX power supply to act as a socket stand-in. The combination of the IN-1's short operational lifespan, obscure base, and abysmally poor, "prop from The Dark Crystal"-style construction make this tube almost universally loathed by electronics hobbyists. |  |
| Soviet Anod IN-2 | |
The IN-2 is the Soviet equivalent of tiny American tubes like the Burroughs 4021. The digit height on the IN-2 is 10mm and the envelope diameter is 17mm, which makes it slightly larger than a 4021. The IN-2 has a high domed front and a side nipple that exits the tube at a 45 degree angle to the digit, for for side-by-side mounting in multiple tube displays. The print on the side of the tube is covered with a resinous coating, which protects the print from being wiped off by the person installing the tube. The main drawback of the tube is its tiny base, the socket for the tube is rather hard to find, and the pin spacing is very narrow, making attachment of leads difficult. It should be noted that while it is common to blindly refer to all Soviet tubes as being manufactured by 'Sovtek', the example shown here was actually manufactured by Anod. |  |
| Soviet Gazotron IN-12 | |
The IN12 is the Soviet analog to Western oval Nixie tubes such as the Burroughs B5991 and 8422. To save on costs, the tube does not have a cathode to represent the number '5', instead an additional '2' stencil is used, mounted upside down. Digit height is 19mm and the diameter of the tube is 30mm at it's widest point. This tube is actually mechanically compatible with the 14 pin sockets used by the B5991, though the underside nipple requires that said sockets have a centrally located perforation for clearance. This tube comes in two slightly different versions, the IN12B, which has a decimal point, and the IN12A, which does not. The IN-12 is widely used by hobbyists in projects, due to it's low cost and general ruggedness. |  |
| Soviet Gazotron IN-17 | |
The IN-17 is believed to be the smallest nixie tube that was manufactured in Russia. Digit height is 9mm and the envelope is only 10mm wide at its narrowest point. The IN-17 has a flying lead base with a colorful plastic spacer to hold the tube away from the board it is being attached to. The spacers on the IN-17 come in a wide array of different colors. |  |
| Soviet Gazotron IN-28 | |
The IN-28 is a top view Soviet neon display tube designed to be used as a single dot indicator in large tiled displays. Large numbers of IN-28 tubes would be chained together to form segmented and dot matrix patterns with each tube acting as a single pixel. The IN-28 uses the same size envelope as the popular Soviet-made IN-4 nixie tube but is equipped with a different base, a 7 pin flying lead type that required the tube to be directly soldered into the target device. The IN-28 is very bright, and displays built using this tube have excellent visibility. |  |
| Soviet Gazotron MTX-90 | |
The MTX90 is a small neon filled thyratron designed specifically for use as a latching single dot indicator, and has a curved glass magnifier incorporated into the top of the tube envelope for this function. The MTX90 was used in a myriad devices in the former Soviet Union, and a causal Google search will turn up examples of the tube lurking in everything from wall switches to quackery-medical skin care lamps. Interestingly, the tube's leads come pre-clipped to length from the factory and each lead has a ball of solder installed on it's base for easy soldering, much like a modern ball grid array integrated circuit. |  |
| Burroughs B-5560 | |
The B-5560 is an oddity, an upside-down mount tube. Unlike most side view nixie tubes, which have leads exiting the bottom of the envelope, the B-5560's leads exit at the top of the envelope. Digit height is 13mm and the height of the envelope is 30mm. Announced in 1967, Burroughs lauded the B-5560 as having a 24% narrower envelope than competing devices, allowing for tighter placement in multi-digit displays. The B-5560 is primarily used in Hewlett Packard test equipment. Note: Despite the color in the photo, the discharge from this tube is orange like other nixie tubes. The bright pink glow in the photo is an artifact of the high amount of UV generated from the glow discharge. |  |
| RFT Z560M | |
The Z560M is a top-view Nixie display in a compactron style envelope with a 13 pin base. Made by RFT, the Z560M is a shorter, stubbier analog to the Burroughs B5092, which is shown below. The upper surface of the Z560M is coated with a layer of translucent red paint, which increases the contrast of the displayed numbers. Digit height on this Z560M is 15mm, the tube has a diameter of 30mm and a height of 24mm. |  |
| Burroughs 7153 | |
The Burroughs 7153 is a large, top-view Nixie tube encased in a stubby cylindrical envelope. This tube is about 20% larger than Burroughs' more plentiful Nixie offerings like the B-5092, and has a digit height of 20mm. Interestingly this tube still uses a standard diameter 13 pin Burroughs socket... the pins are located in the center of a large glass button to accommodate the tube's increased envelope size. The example shown here has seen significant amounts of use, which has caused the glass to cloud over with disintegrated cathode material. |  |
| Burroughs B-5092 | |
The Burroughs B-5092 is a medium sized round top view Nixie with standard numerals and a 13-pin base. The digit height of this tube is 16mm and the envelope is 20mm in diameter. This is one of the most common models of Burroughs Nixie tubes, and saw use in a myriad products. In modern times this was a favorite tube for Nixie clock builders, though lack of availability eventually saw clock designs shifting over to more easily obtained Soviet tubes like the IN12. |  |
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