|
 |  |  |  |
| Dekatron Glow Transfer Counting Tubes |
For technical data, please refer to the Dekatrons of the World reference. |
|
| Ericsson GC10A | |
The GC10A (also known as the GC10/A), is widely considered to be the world's first commercially released dekatron. Designed and manufactured by Ericsson and released in 1949, the GC10A is a two guide, ten position device, and is packaged in the archetypal Ericsson elongated envelope that is used in many of their later dekatron products. Unlike most other dekatrons, the GC10A is filled with helium, which gives the tube its distinctive illumination color. The GC10A's complex internal construction included cathodes that were spot-welded to suspended rings and fixed in place with perforated mica supports. This labor-intensive process was abandoned in later tubes, which use a series of ceramic disks and stamped plates to support the cathodes. |  |
| ETL GC10B Series | |
Devices included in this entry: |  |
| Transitional GC10B | |
This mysterious device is an undocumented transitional form between the first generation Ericsson GC10A and GC10B glow transfer counters. This tube is marked as being a "GC10B" in the standard early Ericsson white print, but instead of neon, the tube is filled with helium much like a GC10A. This strange device also has an identical internal construction to the Ericsson GC10A shown above. We are unsure how this tube came to exist; it could be an early prototype or engineering sample of the GC10B that predates the decision to use a neon fill gas, or it could be a manufacturing error or specialty item for a specific vendor. |  |
| Sylvania 6802 & 6909 | |
Devices included in this entry: Raytheon made second-source versions of these tubes, prefixed by a CK identifier in the part number. The CK variants of these tubes are electrically identical, despite their vastly different internal construction. |  |
| ETL GC12/4B | |
The GC12/4B is a counting tube oddity: a 'dekatron' that is designed to count in base-12 instead of base-10. Base-12 tubes served an important niche function, since the hour of the day is typically measured in 12 or 24 positions, they allowed designers to save an entire tube in any device that measured the time of day. |  |
| ETL GC10D | |
The GC10D is a single pulse tube with three guides and forty cathode positions. The maximum counting speed is rated at 20kHz, but only when fed with a sine wave input pulse. When driven with a square wave, the maximum speed is only 10kHz. This is one of the most failure-prone dekatrons ever built; the tube's fill gas is over seventy percent helium, and is almost always absent by the time the tube falls into the hands of a collector. |  |
| ETL GS12C | |
The GS12C is a strange card in the Ericsson dekatron family: a base-12 selector with a maintenance base. This unusual base allows for connection of wire leads directly to the base of the tube, without any need for a socket. The duodecal sockets used on other ETL selector dekatrons will not work in their standard form on a tube like the GS12C, as a base-12 selector would require 14 pins to connect all of its cathodes. |  |
| Ericsson GC10/2P | |
Ericsson's sole entry into the miniature counting tube arena, the GC10/2P is a rather unusual device. This tube uses a unique construction style in which cathode and guide rings are constructed from single sheets of folded sheet metal, similar to the method employed by the 'Wales Counter' described above. The cathodes are held in a ceramic sandwich that confines the glow to the top portion of the tube, taken together the entire counting ring is much easier to manufacture than the complex arrays of welded cathode pins seen in many tubes. This tube is a bidirectional double pulse device, with a full 30 cathodes and a neon fill gas. The tube's 1khz counting speed puts it squarely at the bottom of the pack compared to other miniature counting tubes, though to be fair, many of those tubes are much less versatile unidirectional devices. The GC10/2P was a rather short-lived tube, and it is fairly rare as a result. ETL GC10/2P Datasheet (PDF) |  |
| ETL GS10E | |
The GS10E, despite its pedestrian appearance, is a quite rare tube; as it appears to be the last model of dekatron Ericsson manufactured before switching over to compact envelope counting tubes. In outward appearance this tube looks like a standard ETL bidirectional selector with no shade ring, there is no obvious enhancement to explain the existence of this part within ETL's vast array of dekatron products. This tube appears to use some sort of Penning mixture, the exact gas mix is unknown, but the tube illuminates with a pale orange hue that is noticeably different from the earlier neon filled ETL tubes like the GC10B. The tube's 10Khz counting speed is slower than the hydrogen-rich ETL high speed tubes, but faster than neon filled tubes like the GS10C. The near total lack of GS10E's in the tube collector marketplace suggests that very few units were actually manufactured. |  |
| ETL GS10H | |
The GS10H is a two-guide compact envelope dekatron, manufactured by ETL and it's various subsidiaries. GS10H tubes are neon filled but slightly faster than ETL's earlier dekatrons, the GS10H has a rated counting speed of 5khz, compared to the GS10C's 4khz count speed. The GS10H utilizes a 17 pin base, and will fit into 27 pin beam switching tube sockets as well as the 17 pin sockets specifically designed for this tube. |  |
| ETL GC10/4C | |
The GC10/4C neon-filled bidirectional counter is a later model British dekatron, no doubt intended to be a replacement for the GC10/4B. Though the GC10/4C is nearly identical to the GC10/4B from an electrical standpoint, it is quite different in construction. The tube abandons the long, phallic envelope common to previous Ericsson counters in favor of a short, compact envelope that is no longer than a standard octal tube. The 8 pin base is actually the same diameter as the tube envelope: the bottom of the glass envelope narrows to allow it to fit within the inside diameter of the base. The result is an aesthetically pleasing tube that will fit in any device designed for a standard-length octal tube, while still maintaining a distinctive shape. The lineage of the GC10/4C is a bit of a mystery... it is a fairly hard to find tube, and does not appear in any of the standard Ericsson databooks. Collectors are still unsure of exactly how or where it fits into Ericsson's dekatron product line. |  |
| ETL GS12D | |
Devices included in this entry: |  |
| ETL GCA10G & GSA10G | |
Devices included in this entry: The GCA10G is an earlier counting-only variant of Ericcson direct drive technology, and lacks many refinements, such as the finned primary anode and curved secondary anodes. (GCA10G's with late date codes seem to adopt these features.) The GCA10G's lack of selector output cuts the pins on the base down to 18, compare this to the GSA10G, which has a monstrous modified 27 pin base with an extra pin in the center of the socket. Unfortunately the GSA10G and GCA10G were a technology that few actually felt was necessary. Dekatrons already directly indicate their count position, and few felt the substantial additional cost of a Nixie tube was worth it just to give counter operators an Arabic character to stare at. Very few direct drive dekatron part numbers were made and fewer still were used in products. The GSA10G example shown here is actually an Ericsson development sample; the label includes terse warnings about the lack of future supply. |  |
| Burroughs BG08220-K | |
The BG08220-K, manufactured by Burroughs, is a glow transfer counting display that defies all conventions of dekatron construction. The most obvious difference between the BG08220-K and other dekatron tubes is that the BG08220-K is not even a "tube"; Burroughs constructed the device using a glass sandwich system similar to the construction style used in their Panaplex displays. The BG08220-K is a base-24 device, the only base-24 counting tube such known, and the non-guide cathode positions are elongated and easily seen through the front of the device. The tube also has four guides, double the amount used in a standard dekatron, and is filled with neon gas for easily visibility. The BG08220-K is designed primarily for display instead of counting, and has only a single output cathode located at the 6-o'clock position. |  |
| Mullard Z302C | |
The Z302C is one of the only dekatron tubes manufactured by Mullard that was not merely a clone of a more popular Ericsson part number. It's internal construction is somewhat unusual, as Z302C tubes are designed to be directly coupled into multi-stage counters with no intermediate active components. Though the tube has 30 cathodes it is not intended to be driven in a 2-guide fashion, as the tube only has one set of guides, located in the first position after each main cathode. The second electrode positions are designated as 'extinguishing electrodes' and are wired in two groups, based on whether the given extinguishing electrode precedes an even numbered cathode position or an odd numbered position. In normal operation the extinguishing electrodes are not tied to a phase shifted version of the input pulse signal, they are driven by the successive charge and discharge of an external capacitor network. The zero position extinguishing electrode , shown in the inset photo to the left, sits outside the count loop and is tied to a -300 volt supply. When the glow transfer reaches the zero position electrode, the sudden increase in current draw produces a pulse at the anode of the tube, which can be directly propagated into the guide of an adjacent counter. Overall, this system of counting is rather clumsy, requires a separate -300 volt supply, and limits the tube's count speed to a mere 1kHz. |  |
| Mullard Z504S & Z505S | |
Devices included inMullard Z504S Series this entry: The Z504S is the standard 4kHz counterpart to the Z505S and is identical in envelope and internal construction other than its more stable neon fill gas |  |
| Raytheon 7978 & 8262 | |
Devices included in this entry: |  |
| RFT Z562S | |
The Z562S is a German made compact envelope dekatron selector. The Z562 is a neon filled tube very similar to the Sylvania 8353, but has a faster maximum counting speed of 5kHz. The taller than average envelope of the Z562 has a high domed top and heavy shade ring, this tube is a uncommon but visually appealing choice for use in a project. |  |
| RFT Z563C | |
The Z563C is RFT's counting only variant of the Z562S selector tube shown above. This tube has the same envelope and identical stats to the Z562S; a 5kHz maximum counting speed with a neon fill gas. Unlike the Z562S which has a 13 pin base, this tube has a standard 9 pin 'Magnoval' base, and uses commonly available sockets. Four of the pins on the base are stubs and not connected to anything, this tube has only a single output cathode. |  |
| Rodan DK23 | |
Even the Japanese joined the dekatron market with tubes like the DK23, a single-pulse counter with three guides and forty cathode positions. Counting speed is rated at a capable 20 kHz and the fill gas is unknown, but appears to be some sort of Penning mixture consisting of a melange of hydrogen, neon, and other trace gases. Though difficult to find, these tubes are much more robust than ETL's competing single-pulse GC10D, and rarely fail from outgassing. |  |
| Rodan DK24 | |
Another uncommon Japanese counting tube, the DK24 is Rodan's selector counterpart to the single-output DK23. The most striking feature of the DK24 is its unusual base, a 14 pin loctal style with a metal keying post and ring epoxied to the bottom of the tube. The DK24 has similar specs to the DK23; single pulse configuration with forty cathodes, a 20kHz counting speed, and a Penning style fill. |  |
| Soviet Anod OG-3 | |
The OG-3 is a single-pulse dekatron with 40 cathodes and an unusual extra output cathode. This dekatron's 20 kHz counting speed is largely due to its helium-hydrogen fill, which gives the tube a purple discharge. The OG3 is currently the most common dekatron in the world, as Soviet surplus floods the international market. This example is a somewhat rarer metal base variant. It should be noted that while it was historically common to blindly refer to all Soviet tubes as being manufactured by 'Sovtek', the example shown here was actually manufactured by Anod. |  |
| Soviet Anod OG-4 Series | |
Devices included in this entry: |  |
| Soviet Melz OG-8 | |
The OG-8 is a very unusual high speed counting tube. The tube is a single guide, unidirectional design with a metal octal base. The tube has 20 bent cathodes under a heavy shade ring, five of which are brought out to individual pins on the base. The tube's rated counting speed is 100Khz and the fill gas in unknown, though it appears to contain a mix of hydrogen and other gases. The OG-8's anode voltage is much higher than other dekatrons: the tube must be driven at over 500 volts to achieve ionization. Normal dekatron driver circuits have trouble spinning the OG-8, and the home experimenter should not expect a stock spinner design to work reliably with this tube. |  |
| Soviet Anod A-101 Series | |
Devices included in this entry: The A-101 design saw significant improvements in the A-102, which introduced an argon fill, and the A-103, which incorporates some minor internal changes. |  |
| Soviet Anod A106 | |
The A-106 is the selector companion to the Soviet-made OG-8 counter tube shown above. Like the OG-8, the A-106 is a unidirectional tube with 20 shaped cathodes that angle in the direction the tube is intended to spin. Unlike the OG-8, the A-106 has a large phenolic 13 pin base, and each output cathode is brought out to a separate pin. The A-106 is a fast tube; it's maximum rated counting speed is 100kHz, but it also requires a higher anode voltage than many dekatrons and will not function reliably with most of the spinner circuits available on the Internet. |  |
| Soviet Anod A108 Series | |
Devices included in this entry: The Soviets did have a scheme to use this tube as a base-10 counter, in which no cathodes were designated as outputs. To pull it off, even and odd number cathodes were each fed half of an out-of-phase signal from a flip-flop circuit. Standard dekatron offset guide pulses will not work for this, the signals on the even and odd numbered cathodes must be exactly 180 degrees out of phase for the tube to count correctly. Such a system was highly impractical, as it required a transistor across every cathode that needed to double as an output as well as the active components necessary to generate the flip-flop signal. |  |
| Soviet A-201 Polyatron | |
Though the A-201 looks similar to a dekatron, this strange device is actually a polyatron tube, also known as an inverse dekatron. The A-201 operates in reverse of a normal dekatron; the tube has a ring of ten anodes surrounding a central cathode and an encircling screen electrode. The polarity of all supply voltages and incoming pulses are reversed, and removal of the tube's cathode from active participation in the counting process prevents the cathode poisoning that can foul normal dekatrons. The encircling screen electrode provides an additional layer of protection against cathode poisoning, by collecting the majority of the sputter material from the cathode and preventing it from fouling the glass of the envelope. The A-201 is not designed for direct view of count position, as the glow transfer occurs in a slot approximately halfway down the length of the tube. Much like a magnetic beam switching tube, the A-201 can be directly coupled to a Nixie display for indication of count position. However, the A-201 is slow compared to its dekatron contemporaries: the tube's maximum counting speed is only 10kHz. Unlike most other Soviet glow transfer counters, which were manufactured at the Anod (Anode) factory, these A-201's were made by Plasma Labs, which is best known for it's lasers and high power transmitting tubes. |  |
| Sylvania 6476A | |
The Sylvania 6476A is an early USA-made neon filled selector. This tube is double guide, with a run-of-the mill 4kHz counting speed and a 12 pin duodecal base. The example shown here has seen heavy use, resulting in a very uneven glow discharge across the cathodes. Sylvania was a prolific manufacturer of dekatrons and the 6476 was one of their most common models. |  |
| Sylvaina CT-783 | |
Most Sylvania CT-prefixed counting tubes, like the CT-4251, are merely internal part number versions of more common production parts. The CT-783 is different however, in that it appears to be the only internal part number Sylvaina tube which never saw a commercially released companion. The CT-783 is a three guide tube with forty cathodes, possibly the only 3 guide tube that Sylvania manufactured. In all other regards the CT-783 bears much in common with the much more readily available 6802, including the same envelope, base, and internal structure. |  |
| Sylvania 6910 | |
Devices included in this entry: |  |
| Sylvania 8035 / CT-4251 Series | |
Devices included in this entry: |  |
| Sylvania 7155 & 6879 | |
Devices included in this entry: |  |
| Elesta EZ10A & EZ10B | |
Devices included in this entry: |  |
| STC G10/241E | |
If a dekatron and a pixie tube were fused together in some sort of horrible, The Fly-style matter transporter accident, a nomotron would probably be the result. Nomotrons function on the principles of glow transfer in the same manner as dekatron tubes do, but instead of relying on an external surround to indicate count position, a nomotron has a metal shield inside the tube which directly indicates count through punched or stamped numbers. The G10/241E, made by STC, is a fairly standard representative example of the nomotron form factor. The G10/241E is a unidirectional tube, with angled sheet metal cathodes hidden under its metal shroud. Unlike many other unidirectional tubes, the direction of the glow transfer is not controlled by the slant of the cathodes. Instead, each guide cathode has extremities constructed of different alloys with different maintaining voltages. These multi-alloy cathodes are reported to substantially increase the count accuracy of the tube, but require numerous additional external components in the form of resistor-capacitor networks attached to the guide cathodes. The count position indicators on this tube are not stamped on the metal, but rather printed on a mica disc mounted above the shroud. The tube has a stubby wide envelope and an attractive metal duodecal base. |  |
| Tesla 11TU7 | |
Tesla's 11TU7 nomotron represents what would seem to be a final logical endpoint for a world that contains both dekatron counting tubes and pixie tubes, a glow transfer counter with actual numeral-shaped discharge indicators like a pixie tube. Despite appearances the numerals at the top of this tube are not actually cut into the shield, but are instead printed on a mica sheet. Holes punched in the shield backlight each numeral when the given cathode is selected. The 11TU7 is a 20khz unidirectional device; the tube's shaped cathodes are hidden below it's metal shroud. The tube is attractively packaged in a stubby blue painted envelope with yellow print and a metal duodecal base. Unfortunately, the example shown here is outgassed, so you will have to use your imagination to picture what an functioning 11TU7 looks like. In operation, the tube produces an orange discharge beneath the currently selected number. |  |
| Elesta EZ10 | |
Nomotrons are strange devices. However, even among the world of nomotrons, the EZ10 is unique. With its tiny miniature envelope and 50kHz counting speed, the EZ10 is the the smallest, fastest nomotron currently known. Like the more readily available EZ10A and EZ10B, the EZ10 has 20 shaped cathodes, an argon fill gas, and a tiny 13 pin base. The pinouts of the EZ10 are somewhat different than the more common EZ10A; the guide cathodes are tied into even and odd groups instead of left and right groups, which prevents the tube from operating in a base-5 configuration. Unlike other nomotrons, the tiny mask plate at the top of the tube does not have any number markings. Another unusual feature is that the mask plate in the EZ10 does not extend down to cover the tube's internal structure, which allows the cathode and guide structures to be easily seen through the side of the tube. |  |
| Elesta ECT100 | |
The EZ10 may be strange, but the ECT100 is truly bizarre. The ECT100 is a 1 MHz bidirectional hydrogen-filled selector with only 20 cathode positions. This seemingly impossible feat is accomplished by a highly innovative internal design in which both guides and cathodes are driven with pulse waveforms. The tube has four distinct cathode structures, each of which is arranged as a ring of five spade-shaped posts connected to a central disk. Two of the cathode structures are designated as output cathodes, and the other two are designated as guide cathodes. In operation, the two output cathodes are driven with alternating waveforms and the two guide cathodes are driven with slightly delayed signals from the output cathodes. By reversing the connections between the output cathodes and the guide cathodes, the rotation direction can be reversed, allowing for a complete bidirectional base-ten count operation to be carried out in a tube that has only 20 cathode positions. With all of the ECT100's cathodes tied up as waveform inputs, a rather interesting method must be used to read the tube's state. Below each of the tube's output cathode spades is a forked sense anode, which projects upward around either side of the spade. When a given spade is ionized, the glow will exit from slits on either side of the spade, enveloping the sense anode. This causes a probe current to flow back through the anode, which is sensed on one of the tube's ten supplemental anode pins. The ECT100's combination of speed, function, and size make it likely the most advanced dekatron ever made. Despite this, it was birthed into obsolescence, its release coinciding with the introduction of small-scale integrated circuits. As a result, the ECT100 was narrowly implemented in its time, and is virtually nonexistent today. |  |
| Western Electric 6167 | |
The Western Electric 6167 is a very unusual counting tube. Instead of having pins or bent cathodes like most other dekatrons, the 6167 uses tiny springs for its cathodes. Each spring has a small finger, which exits the top of the spring and hangs over the center of the adjacent cathode. It requires less maintaining voltage to hold a glow discharge within a tube-shaped cathode than upon the surface of rod-shaped cathode, and the 6167 is designed to take full advantage of this phenomenon. During operation the glow will rest in the center of each spring, jumping to the finger only during glow transfer. The 6167's unusual cathode construction makes it a unidirectional tube, with ten output cathodes and ten guide cathodes. The guide cathodes are spit into two groups of five, to allow for base five or base ten counting. The tube actually has 21 cathodes: a single "zeroing" cathode sits outside the counting ring and feeds into the first count position at an angle. The tube can be reset to the zero position by pulling the zeroing cathode to ground without interrupting the counting loop. The tube also has a supplemental anode, which sits between the normal anode and the final output cathode in the counting loop. This anode is used to provide a carry without interrupting the counting loop - the supplemental anode is pulled low as the glow transfer passes by it. It should be noted that even though this tube uses an unusual 16-pin base, it can be used with normal Cinch 13-pin nixie tube sockets due to the cylindrical void located in their center. The 6167 will also fit 20-pin sockets like those used for the MO-10R beam switching tube. |  |
| Ericsson RYG10 | |
This bizarre device could easily be considered the most unusual counting tube ever made. The Ericsson RYG10 is an early two-electrode magnetic beam switching tube, which utilizes the crossed-field effect to implement a 10 stage decade counter in a single tube envelope. Unlike a Dekatron, which displays its count through the ionization of a low pressure fill gas, the RYG10 is a hard vacuum device that uses phosphor coated targets to display count position. These funnel shaped targets, which are located in a ring at the top of the tube, are lit sequentially by the rotating electron beam projecting from the center of the tube. A specially designed socket and external magnetic ring are required for the RYG10 to function correctly; the socket includes a raised flange that centers the magnet in the proper position relative to the tube's axis. The RYG10 has a maximum counting speed of 1 MHz. |  |
| ©2000-2024 Industrial Alchemy. All rights reserved. | Switch to mobile version | Contact | |  |