1798:
1843:(who conceived Colossus) wrote that most radio equipment was "carted round, dumped around, switched on and off and generally mishandled. But I'd introduced valves into telephone equipment in large numbers before the war and I knew that if you never moved them and never switched them on and off they would go on forever". Colossus was "that reliable, extremely reliable". On its first day at BP a problem with a known answer was set. To the amazement of BP (Station X), after running for four hours with each run taking half an hour the answer was the same every time (the Robinson did not always give the same answer). Colossus I used about 1600 valves, and Colossus II about 2400 valves (some sources say 1500 (Mk I) and 2500 (Mk II); the Robinson used about a hundred valves; some sources say fewer).
1375:. This 1920s device has three triodes in a single glass envelope together with all the fixed capacitors and resistors required to make a complete radio receiver. As the Loewe set had only one tube socket, it was able to substantially undercut the competition, since, in Germany, state tax was levied by the number of sockets. However, reliability was compromised, and production costs for the tube were much greater. In a sense, these were akin to integrated circuits. In the United States, Cleartron briefly produced the "Multivalve" triple triode for use in the Emerson Baby Grand receiver. This Emerson set also has a single tube socket, but because it uses a four-pin base, the additional element connections are made on a "mezzanine" platform at the top of the tube base.
2490:"Special quality" versions of standard tubes were often made, designed for improved performance in some respect, such as a longer life cathode, low noise construction, mechanical ruggedness via ruggedized filaments, low microphony, for applications where the tube will spend much of its time cut off, etc. The only way to know the particular features of a special quality part is by reading the datasheet. Names may reflect the standard name (12AU7==>12AU7A, its equivalent ECC82==>E82CC, etc.), or be absolutely anything (standard and special-quality equivalents of the same tube include 12AU7, ECC82, B329, CV491, E2163, E812CC, M8136, CV4003, 6067, VX7058, 5814A and 12AU7A).
2108:, also extended to transistors, uses a letter, followed by one or more further letters, and a number. The type designator specifies the heater voltage or current (one letter), the functions of all sections of the tube (one letter per section), the socket type (first digit), and the particular tube (remaining digits). For example, the ECC83 (equivalent to the 12AX7) is a 6.3V (E) double triode (CC) with a miniature base (8). In this system special-quality tubes (e.g., for long-life computer use) are indicated by moving the number immediately after the first letter: the E83CC is a special-quality equivalent of the ECC83, the E55L a power pentode with no consumer equivalent.
650:: the voltage applied to the control grid affects the current between the cathode and the plate. When held negative with respect to the cathode, the control grid creates an electric field that repels electrons emitted by the cathode, thus reducing or even stopping the current between cathode and anode. As long as the control grid is negative relative to the cathode, essentially no current flows into it, yet a change of several volts on the control grid is sufficient to make a large difference in the plate current, possibly changing the output by hundreds of volts (depending on the circuit). The solid-state device which operates most like the pentode tube is the
2517:
2460:, may be incorporated in the equipment's heater supply or a ramp-up circuit may be employed to allow the heater or filaments to reach operating temperature more gradually than if powered-up in a step-function. Low-cost radios had tubes with heaters connected in series, with a total voltage equal to that of the line (mains). Some receivers made before World War II had series-string heaters with total voltage less than that of the mains. Some had a resistance wire running the length of the power cord to drop the voltage to the tubes. Others had series resistors made like regular tubes; they were called ballast tubes.
1237:
1233:, eliminating the need for neutralizing circuitry at medium wave broadcast frequencies. The screen grid also largely reduces the influence of the plate voltage on the space charge near the cathode, permitting the tetrode to produce greater voltage gain than the triode in amplifier circuits. While the amplification factors of typical triodes commonly range from below ten to around 100, tetrode amplification factors of 500 are common. Consequently, higher voltage gains from a single tube amplification stage became possible, reducing the number of tubes required. Screen grid tubes were marketed by late 1927.
940:
2300:
1545:
1702:
the cathode circuit to be separated from the heater circuit. The filament, no longer electrically connected to the tube's electrodes, became simply known as a "heater", and could as well be powered by AC without any introduction of hum. In the 1930s, indirectly heated cathode tubes became widespread in equipment using AC power. Directly heated cathode tubes continued to be widely used in battery-powered equipment as their filaments required considerably less power than the heaters required with indirectly heated cathodes.
1650:
2117:
1858:
37:
1751:, "discovered that, so long as valves were switched on and left on, they could operate reliably for very long periods, especially if their 'heaters' were run on a reduced current". In 1934 Flowers built a successful experimental installation using over 3,000 tubes in small independent modules; when a tube failed, it was possible to switch off one module and keep the others going, thereby reducing the risk of another tube failure being caused; this installation was accepted by the
2775:
569:, will attract those electrons if it is at a more positive voltage. The result is a net flow of electrons from the filament to plate. However, electrons cannot flow in the reverse direction because the plate is not heated and does not emit electrons. The filament has a dual function: it emits electrons when heated; and, together with the plate, it creates an electric field due to the potential difference between them. Such a tube with only two electrodes is termed a
287:
1606:
483:
2425:
1906:
cutoff with the heater on accelerates cathode poisoning and the output current of the tube will be greatly reduced when switched into conduction mode. The 7AK7 tubes improved the cathode poisoning problem, but that alone was insufficient to achieve the required reliability. Further measures included switching off the heater voltage when the tubes were not required to conduct for extended periods, turning on and off the heater voltage with a slow ramp to avoid
460:
143:
2600:, comes from helium infiltration. The effect appears as impaired or absent functioning, and as a diffuse glow along the electron stream inside the tube. This effect cannot be rectified (short of re-evacuation and resealing), and is responsible for working examples of such tubes becoming rarer and rarer. Unused ("New Old Stock") tubes can also exhibit inert gas infiltration, so there is no long-term guarantee of these tube types surviving into the future.
922:(or simply "grid") was lowered from the cathode's voltage to somewhat more negative voltages, the amount of current from the filament to the plate would be reduced. The negative electrostatic field created by the grid in the vicinity of the cathode would inhibit the passage of emitted electrons and reduce the current to the plate. With the voltage of the grid less than that of the cathode, no direct current could pass from the cathode to the grid.
131:
2638:
vacuum tubes were more efficient than solid-state circuits at RF power levels above approximately 20 kilowatts, this is no longer the case, especially in medium wave (AM broadcast) service where solid-state transmitters at nearly all power levels have measurably higher efficiency. FM broadcast transmitters with solid-state power amplifiers up to approximately 15 kW also show better overall power efficiency than tube-based power amplifiers.
1962:
3461:
3139:
857:
2718:(being a highly reactive metal) is effective against many atmospheric gases but has no (or very limited) chemical reactivity to inert gases such as helium. One progressive type of failure, especially with physically large envelopes such as those used by camera tubes and cathode-ray tubes, comes from helium infiltration. The exact mechanism is not clear: the metal-to-glass lead-in seals are one possible infiltration site.
769:
2241:
but was only permitted to conduct when the igniter in contact with the mercury had enough current to vaporize the mercury and complete the circuit. Because this was used in resistance welding there were two
Ignatrons for the two phases of an AC circuit. Because of the mercury at the bottom of the tube they were extremely difficult to ship. These tubes were eventually replaced by SCRs (Silicon Controlled Rectifiers).
2506:
663:
3290:
2573:
on the inside of the glass envelope, leaving a silver-colored metallic patch that continues to absorb small amounts of gas that may leak into the tube during its working life. Great care is taken with the valve design to ensure this material is not deposited on any of the working electrodes. If a tube develops a serious leak in the envelope, this deposit turns a white color as it reacts with atmospheric
1763:, with over 17,000 tubes, had a tube failure (which took 15 minutes to locate) on average every two days. The quality of the tubes was a factor, and the diversion of skilled people during the Second World War lowered the general quality of tubes. During the war Colossus was instrumental in breaking German codes. After the war, development continued with tube-based computers including, military computers
3061:
1723:
872:
1314:
1196:
514:, although ceramic and metal envelopes (atop insulating bases) have been used. The electrodes are attached to leads which pass through the envelope via an airtight seal. Most vacuum tubes have a limited lifetime, due to the filament or heater burning out or other failure modes, so they are made as replaceable units; the electrode leads connect to pins on the tube's base which plug into a
2026:
5343:
1573:
827:) when the plate was at a positive voltage with respect to the cathode. Electrons could not pass in the reverse direction because the plate was not heated and not capable of thermionic emission of electrons. Fleming filed a patent for these tubes, assigned to the Marconi company, in the UK in November 1904 and this patent was issued in September 1905. Later known as the
2034:
1453:
2581:. Early gettered tubes used phosphorus-based getters, and these tubes are easily identifiable, as the phosphorus leaves a characteristic orange or rainbow deposit on the glass. The use of phosphorus was short-lived and was quickly replaced by the superior barium getters. Unlike the barium getters, the phosphorus did not absorb any further gases once it had fired.
880:
719:, that became well known. Although Edison was aware of the unidirectional property of current flow between the filament and the anode, his interest (and patent) concentrated on the sensitivity of the anode current to the current through the filament (and thus filament temperature). It was years later that
1360:(at a high voltage). Many designs use such a screen grid as an additional anode to provide feedback for the oscillator function, whose current adds to that of the incoming radio frequency signal. The pentagrid converter thus became widely used in AM receivers, including the miniature tube version of the "
2947:
was marketed, but did not last.) However, eventually, Philips of the
Netherlands developed the EFP60 tube that had a satisfactory lifetime and was used in at least one product, a laboratory pulse generator. By that time, however, transistors were rapidly improving, making such developments superfluous.
2464:
lower-powered tubes. The result was that heaters that warmed up faster also temporarily had higher resistance, because of their positive temperature coefficient. This disproportionate resistance caused them to temporarily operate with heater voltages well above their ratings, and shortened their life.
2965:
made a high-performance wideband oscilloscope CRT with a channel electron multiplier plate behind the phosphor layer. This plate was a bundled array of a huge number of short individual c.e.m. tubes that accepted a low-current beam and intensified it to provide a display of practical brightness. (The
2691:
included in the circuit. Tubes intended for series-string operation of the heaters across the supply have a specified controlled warm-up time to avoid excess voltage on some heaters as others warm up. Directly heated filament-type cathodes as used in battery-operated tubes or some rectifiers may fail
2675:
A catastrophic failure is one that suddenly makes the vacuum tube unusable. A crack in the glass envelope will allow air into the tube and destroy it. Cracks may result from stress in the glass, bent pins or impacts; tube sockets must allow for thermal expansion, to prevent stress in the glass at the
2637:
external cavity klystron in the visual circuit of its transmitter; this is the highest documented service life for this type of tube. It has been said that transmitters with vacuum tubes are better able to survive lightning strikes than transistor transmitters do. While it was commonly believed that
2240:
The
Ignatron tube was used in resistance welding equipment in the early 1970s. The Ignatron had a cathode, anode and an igniter. The tube base was filled with mercury and the tube was used as a very high current switch. A large current potential was placed between the anode and cathode of the tube
2100:
is a double triode (two sets of three electrodes plus heater) with a 12.6V heater (which, as it happens, can also be connected to run from 6.3V). The "AX" designates this tube's characteristics. Similar, but not identical, tubes are the 12AD7, 12AE7...12AT7, 12AU7, 12AV7, 12AW7 (rare), 12AY7, and the
2095:
comprise a number, followed by one or two letters, and a number. The first number is the (rounded) heater voltage; the letters designate a particular tube but say nothing about its structure; and the final number is the total number of electrodes (without distinguishing between, say, a tube with many
1905:
pentode of 1948 (these replaced the 7AD7, which was supposed to be better quality than the standard 6AG7 but proved too unreliable). Computers were the first tube devices to run tubes at cutoff (enough negative grid voltage to make them cease conduction) for quite-extended periods of time. Running in
1480:
electrons to the anode when the anode potential is less than that of the screen grid. Formation of beams also reduces screen grid current. In some cylindrically symmetrical beam power tubes, the cathode is formed of narrow strips of emitting material that are aligned with the apertures of the control
1459:
designed for radio frequency use. The tube plugs in to a socket that creates an air-tight seal around the outer periphery. A blower and duct work in the chassis force air through the tube's fins to carry away heat. This type of tube is sometimes referred to as a "doorknob" tube, owing to its shape
958:
brought the Audion for demonstration to AT&T's engineering department. Dr. Harold D. Arnold of AT&T recognized that the blue glow was caused by ionized gas. Arnold recommended that AT&T purchase the patent, and AT&T followed his recommendation. Arnold developed high-vacuum tubes which
2572:
to evolve any remaining gas from the metal parts. The tube is then sealed and the getter trough or pan, for flash getters, is heated to a high temperature, again by radio frequency induction heating, which causes the getter material to vaporize and react with any residual gas. The vapor is deposited
2086:
In many cases, manufacturers and the military gave tubes designations that said nothing about their purpose (e.g., 1614). In the early days some manufacturers used proprietary names which might convey some information, but only about their products; the KT66 and KT88 were "kinkless tetrodes". Later,
2057:
The internal elements of tubes have always been connected to external circuitry via pins at their base which plug into a socket. Subminiature tubes were produced using wire leads rather than sockets, however, these were restricted to rather specialized applications. In addition to the connections at
1499:
Beam power tubes offer the advantages of a longer load line, less screen current, higher transconductance and lower third harmonic distortion than comparable power pentodes. Beam power tubes can be connected as triodes for improved audio tonal quality but in triode mode deliver significantly reduced
1249:
grid since it is also at a positive voltage, robbing them from the plate current and reducing the amplification of the tube. Since secondary electrons can outnumber the primary electrons over a certain range of plate voltages, the plate current can decrease with increasing plate voltage. This is the
2950:
One variant called a "channel electron multiplier" does not use individual dynodes but consists of a curved tube, such as a helix, coated on the inside with material with good secondary emission. One type had a funnel of sorts to capture the secondary electrons. The continuous dynode was resistive,
2946:
For decades, electron-tube designers tried to augment amplifying tubes with electron multipliers in order to increase gain, but these suffered from short life because the material used for the dynodes "poisoned" the tube's hot cathode. (For instance, the interesting RCA 1630 secondary-emission tube
2756:
into the signal. Leakage current due to internal contamination may also inject noise. Some of these effects make tubes unsuitable for small-signal audio use, although unobjectionable for other purposes. Selecting the best of a batch of nominally identical tubes for critical applications can produce
2717:
is used to absorb gases evolved during tube operation but has only a limited ability to combine with gas. Control of the envelope temperature prevents some types of gassing. A tube with an unusually high level of internal gas may exhibit a visible blue glow when plate voltage is applied. The getter
2385:
As a cost reduction measure, especially in high-volume consumer receivers, all the tube heaters could be connected in series across the AC supply using heaters requiring the same current and with a similar warm-up time. In one such design, a tap on the tube heater string supplied the 6 volts needed
2295:
construction and typically came in 22.5-, 45-, 67.5-, 90-, 120- or 135-volt versions. After the use of B-batteries was phased out and rectified line-power was employed to produce the high voltage needed by tubes' plates, the term "B+" persisted in the US when referring to the high voltage source.
2065:
High-power tubes such as transmitting tubes have packages designed more to enhance heat transfer. In some tubes, the metal envelope is also the anode. The 4CX1000A is an external anode tube of this sort. Air is blown through an array of fins attached to the anode, thus cooling it. Power tubes using
1973:
A considerable amount of heat is produced when tubes operate, from both the filament (heater) and the stream of electrons bombarding the plate. In power amplifiers, this source of heat is greater than cathode heating. A few types of tube permit operation with the anodes at a dull red heat; in other
1683:
to a dull red heat (around 700 °C), which in turn reduced thermal distortion of the tube structure and allowed closer spacing of tube elements. This in turn improved tube gain, since the gain of a triode is inversely proportional to the spacing between grid and cathode. Bare tungsten filaments
2283:
batteries, giving nominal heater voltages of 2 V, 4 V or 6 V. In portable radios, dry batteries were sometimes used with 1.5 or 1 V heaters. Reducing filament consumption improved the life span of batteries. By 1955 towards the end of the tube era, tubes using only 50 mA down to as little as 10 mA
1701:
A superior solution, and one which allowed each cathode to "float" at a different voltage, was that of the indirectly heated cathode: a cylinder of oxide-coated nickel acted as an electron-emitting cathode and was electrically isolated from the filament inside it. Indirectly heated cathodes enable
1172:
was developed whereby the RF transformer connected to the plate (anode) would include an additional winding in the opposite phase. This winding would be connected back to the grid through a small capacitor, and when properly adjusted would cancel the Miller capacitance. This technique was employed
1156:
However C batteries continued to be included in some equipment even when the "A" and "B" batteries had been replaced by power from the AC mains. That was possible because there was essentially no current draw on these batteries; they could thus last for many years (often longer than all the tubes)
993:
and used it to settle the question of thermionic emission and conduction in a vacuum. Consequently, General
Electric started producing hard vacuum triodes (which were branded Pliotrons) in 1915. Langmuir patented the hard vacuum triode, but de Forest and AT&T successfully asserted priority and
526:
which performs poorly as an insulator in humid conditions. Other reasons for using a top cap include improving stability by reducing grid-to-anode capacitance, improved high-frequency performance, keeping a very high plate voltage away from lower voltages, and accommodating one more electrode than
2698:
between tube elements can destroy the tube. An arc can be caused by applying voltage to the anode (plate) before the cathode has come up to operating temperature, or by drawing excess current through a rectifier, which damages the emission coating. Arcs can also be initiated by any loose material
1592:
base. In 1938 a technique was developed to use an all-glass construction with the pins fused in the glass base of the envelope. This allowed the design of a much smaller tube profile, known as the miniature tube, having seven or nine pins. Making tubes smaller reduced the voltage where they could
1531:
resemble hard vacuum tubes and fit in sockets designed for vacuum tubes. Their distinctive orange, red, or purple glow during operation indicates the presence of gas; electrons flowing in a vacuum do not produce light within that region. These types may still be referred to as "electron tubes" as
1248:
from the plate. In any tube, electrons strike the plate with sufficient energy to cause the emission of electrons from its surface. In a triode this secondary emission of electrons is not important since they are simply re-captured by the plate. But in a tetrode they can be captured by the screen
1160:
When triodes were first used in radio transmitters and receivers, it was found that tuned amplification stages had a tendency to oscillate unless their gain was very limited. This was due to the parasitic capacitance between the plate (the amplifier's output) and the control grid (the amplifier's
3086:
to solid-state models, often due to the way they tend to distort when overdriven. Any amplifier can only accurately amplify a signal to a certain volume; past this limit, the amplifier will begin to distort the signal. Different circuits will distort the signal in different ways; some guitarists
2447:
hardness and proper selection of construction materials are the major influences on tube lifetime. Depending on the material, temperature and construction, the surface material of the cathode may also diffuse onto other elements. The resistive heaters that heat the cathodes may break in a manner
2319:
voltage. Since no current flows through a tube's grid connection, these batteries had no current drain and lasted the longest, usually limited by their own shelf life. The supply from the grid bias battery was rarely, if ever, disconnected when the radio was otherwise switched off. Even after AC
1132:
operating point in the linear region. This was called the idle condition, and the plate current at this point the "idle current". The controlling voltage was superimposed onto the bias voltage, resulting in a linear variation of plate current in response to positive and negative variation of the
953:
De Forest's original device was made with conventional vacuum technology. The vacuum was not a "hard vacuum" but rather left a very small amount of residual gas. The physics behind the device's operation was also not settled. The residual gas would cause a blue glow (visible ionization) when the
2732:
Cathode depletion is the loss of emission after thousands of hours of normal use. Sometimes emission can be restored for a time by raising heater voltage, either for a short time or a permanent increase of a few percent. Cathode depletion was uncommon in signal tubes but was a frequent cause of
2455:
The heater's failure mode is typically a stress-related fracture of the tungsten wire or at a weld point and generally occurs after accruing many thermal (power on-off) cycles. Tungsten wire has a very low resistance when at room temperature. A negative temperature coefficient device, such as a
2751:
refers to internal vibrations of tube elements which modulate the tube's signal in an undesirable way; sound or vibration pick-up may affect the signals, or even cause uncontrolled howling if a feedback path (with greater than unity gain) develops between a microphonic tube and, for example, a
1782:
Advances using subminiature tubes included the
Jaincomp series of machines produced by the Jacobs Instrument Company of Bethesda, Maryland. Models such as its Jaincomp-B employed just 300 such tubes in a desktop-sized unit that offered performance to rival many of the then room-sized machines.
598:
Early tubes used the filament as the cathode; this is called a "directly heated" tube. Most modern tubes are "indirectly heated" by a "heater" element inside a metal tube that is the cathode. The heater is electrically isolated from the surrounding cathode and simply serves to heat the cathode
1296:
and became generally favored over the simple tetrode. Pentodes are made in two classes: those with the suppressor grid wired internally to the cathode (e.g. EL84/6BQ5) and those with the suppressor grid wired to a separate pin for user access (e.g. 803, 837). An alternative solution for power
1124:
The non-linear operating characteristic of the triode caused early tube audio amplifiers to exhibit harmonic distortion at low volumes. Plotting plate current as a function of applied grid voltage, it was seen that there was a range of grid voltages for which the transfer characteristics were
2463:
Following World War II, tubes intended to be used in series heater strings were redesigned to all have the same ("controlled") warm-up time. Earlier designs had quite-different thermal time constants. The audio output stage, for instance, had a larger cathode and warmed up more slowly than
3307:. This space charge cloud supplies the electrons that create the current flow from the cathode to the anode. As electrons are drawn to the anode during the operation of the circuit, new electrons will boil off the cathode to replenish the space charge. The space charge is an example of an
1678:
led to the development of high-vacuum tubes. After World War I, specialized manufacturers using more economical construction methods were set up to fill the growing demand for broadcast receivers. Bare tungsten filaments operated at a temperature of around 2200 °C. The development of
633:
Except for diodes, additional electrodes are positioned between the cathode and the plate (anode). These electrodes are referred to as grids as they are not solid electrodes but sparse elements through which electrons can pass on their way to the plate. The vacuum tube is then known as a
895:
which used an external magnetic deflection coil and was intended for use as an amplifier in telephony equipment. This von Lieben magnetic deflection tube was not a successful amplifier, however, because of the power used by the deflection coil. Von Lieben would later make refinements to
2008:
In a water-cooled tube, the anode voltage appears directly on the cooling water surface, thus requiring the water to be an electrical insulator to prevent high voltage leakage through the cooling water to the radiator system. Water as usually supplied has ions that conduct electricity;
2662:. An electric heater is inserted into the cathode sleeve and insulated from it electrically by a coating of aluminum oxide. This complex construction causes barium and strontium atoms to diffuse to the surface of the cathode and emit electrons when heated to about 780 degrees Celsius.
3335:
electrons driven off the heated cathode are strongly attracted by the positive anode. The control grid(s) in a tube mediate this current flow by combining the small AC signal current with the grid's slightly negative value. When the signal sine (AC) wave is applied to the grid, it
2926:
causing more electrons to be released from that dynode. Those electrons are accelerated toward another dynode at a higher voltage, releasing more secondary electrons; as many as 15 such stages provide a huge amplification. Despite great advances in solid-state photodetectors (e.g.
3045:
In military applications, a high-power vacuum tube can generate a 10–100 megawatt signal that can burn out an unprotected receiver's frontend. Such devices are considered non-nuclear electromagnetic weapons; they were introduced in the late 1990s by both the U.S. and Russia.
1742:
of tubes were limiting factors. "The common wisdom was that valves—which, like light bulbs, contained a hot glowing filament—could never be used satisfactorily in large numbers, for they were unreliable, and in a large installation too many would fail in too short a time".
1885:
coating. This "cathode interface" is a high-resistance layer (with some parallel capacitance) which greatly reduces the cathode current when the tube is switched into conduction mode. Elimination of silicon from the heater wire alloy (and more frequent replacement of the
606:
The filaments require constant and often considerable power, even when amplifying signals at the microwatt level. Power is also dissipated when the electrons from the cathode slam into the anode (plate) and heat it; this can occur even in an idle amplifier due to the
2620:
to the surface to replace them. Such thoriated tungsten cathodes usually deliver lifetimes in the tens of thousands of hours. The end-of-life scenario for a thoriated-tungsten filament is when the carbonized layer has mostly been converted back into another form of
599:
sufficiently for thermionic emission of electrons. The electrical isolation allows all the tubes' heaters to be supplied from a common circuit (which can be AC without inducing hum) while allowing the cathodes in different tubes to operate at different voltages.
2155:
is a special-purpose tube filled with low-pressure gas or mercury vapor. Like vacuum tubes, it contains a hot cathode and an anode, but also a control electrode which behaves somewhat like the grid of a triode. When the control electrode starts conduction, the
611:
necessary to ensure linearity and low distortion. In a power amplifier, this heating can be considerable and can destroy the tube if driven beyond its safe limits. Since the tube contains a vacuum, the anodes in most small and medium power tubes are cooled by
1593:
safely operate, and also reduced the power dissipation of the filament. Miniature tubes became predominant in consumer applications such as radio receivers and hi-fi amplifiers. However, the larger older styles continued to be used especially as higher-power
3302:
When a cathode is heated and reaches an operating temperature around 1,050 K (780 °C; 1,430 °F), free electrons are driven from its surface. These free electrons form a cloud in the empty space between the cathode and the anode, known as the
2049:
have also been used. A first version of the 6L6 used a metal envelope sealed with glass beads, while a glass disk fused to the metal was used in later versions. Metal and ceramic are used almost exclusively for power tubes above 2 kW dissipation. The
2497:'s main Northern Ireland transmitter at Lisnagarvey. The valve was in service from 1935 until 1961 and had a recorded life of 232,592 hours. The BBC maintained meticulous records of their valves' lives with periodic returns to their central valve stores.
2480:) and glasses had been developed for light bulbs that expanded and contracted in similar amounts, as temperature changed. These made it easy to construct an insulating envelope of glass, while passing connection wires through the glass to the electrodes.
1637:. The nuvistor was developed to compete with the early transistors and operated at higher frequencies than those early transistors could. The small size supported especially high-frequency operation; nuvistors were used in aircraft radio transceivers,
1153:, avoiding the need for a separate negative power supply. For cathode biasing, a relatively low-value resistor is connected between the cathode and ground. This makes the cathode positive with respect to the grid, which is at ground potential for DC.
2536:
between the tube electrodes and cause overheating of the electrodes, producing more gas, damaging the tube and possibly other components due to excess current. To avoid these effects, the residual pressure within the tube must be low enough that the
1868:
To meet the reliability requirements of the 1951 US digital computer
Whirlwind, "special-quality" tubes with extended life, and a long-lasting cathode in particular, were produced. The problem of short lifetime was traced largely to evaporation of
1653:
Commercial packaging for vacuum tubes used in the latter half of the 20th century including boxes for individual tubes (bottom right), sleeves for rows of the boxes (left), and bags that smaller tubes would be put in by a store upon purchase (top
814:
because it passed current in only one direction. The cathode was a carbon lamp filament, heated by passing current through it, that produced thermionic emission of electrons. Electrons that had been emitted from the cathode were attracted to the
2616:. An extremely thin (molecular) layer of thorium atoms forms on the outside of the wire's carbonized layer and, when heated, serve as an efficient source of electrons. The thorium slowly evaporates from the wire surface, while new thorium atoms
2000:
The anode is often treated to make its surface emit more infrared energy. High-power amplifier tubes are designed with external anodes that can be cooled by convection, forced air or circulating water. The water-cooled 80 kg, 1.25 MW
2386:
for the dial light. By deriving the high voltage from a half-wave rectifier directly connected to the AC mains, the heavy and costly power transformer was eliminated. This also allowed such receivers to operate on direct current, a so-called
1697:
introduced mains-frequency (50 or 60 Hz) hum into audio stages. The invention of the "equipotential cathode" reduced this problem, with the filaments being powered by a balanced AC power transformer winding having a grounded center tap.
2415:
To avoid the warm-up delay, "instant on" television receivers passed a small heating current through their tubes even when the set was nominally off. At switch on, full heating current was provided and the set would play almost immediately.
1146:, for which the letter denotes its size and shape). The C battery's positive terminal was connected to the cathode of the tubes (or "ground" in most circuits) and whose negative terminal supplied this bias voltage to the grids of the tubes.
1977:
The requirements for heat removal can significantly change the appearance of high-power vacuum tubes. High power audio amplifiers and rectifiers required larger envelopes to dissipate heat. Transmitting tubes could be much larger still.
2721:
Gas and ions within the tube contribute to grid current which can disturb operation of a vacuum-tube circuit. Another effect of overheating is the slow deposit of metallic vapors on internal spacers, resulting in inter-element leakage.
2541:
of an electron is much longer than the size of the tube (so an electron is unlikely to strike a residual atom and very few ionized atoms will be present). Commercial vacuum tubes are evacuated at manufacture to about 0.000001 mmHg
842:, the Fleming valve offered advantage, particularly in shipboard use, over the difficulty of adjustment of the crystal detector and the susceptibility of the crystal detector to being dislodged from adjustment by vibration or bumping.
2324:, eliminating the need for a third power supply voltage; this became practical with tubes using indirect heating of the cathode along with the development of resistor/capacitor coupling which replaced earlier interstage transformers.
1948:
air-defense computer system. By the late 1950s, it was routine for special-quality small-signal tubes to last for hundreds of thousands of hours if operated conservatively. This increased reliability also made mid-cable amplifiers in
1992:
Tubes which generate relatively little heat, such as the 1.4-volt filament directly heated tubes designed for use in battery-powered equipment, often have shiny metal anodes. 1T4, 1R5 and 1A7 are examples. Gas-filled tubes such as
2998:
produced by giant solar flares. This property kept them in use for certain military applications long after more practical and less expensive solid-state technology was available for the same applications, as for example with the
925:
Thus a change of voltage applied to the grid, requiring very little power input to the grid, could make a change in the plate current and could lead to a much larger voltage change at the plate; the result was voltage and power
3702:
The electronics age may be said to have been ushered in with the invention of the vacuum diode valve in 1902 by the Briton John
Fleming (himself coining the word 'electronics'), the immediate application being in the field of
5793:
1382:). Constraints due to the number of external pins (leads) often forced the functions to share some of those external connections such as their cathode connections (in addition to the heater connection). The RCA Type 55 is a
1684:
remain in use in small transmitting tubes but are brittle and tend to fracture if handled roughly—e.g. in the postal services. These tubes are best suited to stationary equipment where impact and vibration is not present.
2824:
and industrial heating. Traveling-wave tubes (TWTs) are very good amplifiers and are even used in some communications satellites. High-powered klystron amplifier tubes can provide hundreds of kilowatts in the UHF range.
1692:
The desire to power electronic equipment using AC mains power faced a difficulty with respect to the powering of the tubes' filaments, as these were also the cathode of each tube. Powering the filaments directly from a
646:, etc., depending on the number of grids. A triode has three electrodes: the anode, cathode, and one grid, and so on. The first grid, known as the control grid, (and sometimes other grids) transforms the diode into a
518:. Tubes were a frequent cause of failure in electronic equipment, and consumers were expected to be able to replace tubes themselves. In addition to the base terminals, some tubes had an electrode terminating at a
1624:
Sub-miniature tubes with a size roughly that of half a cigarette were used in consumer applications as hearing-aid amplifiers. These tubes did not have pins plugging into a socket but were soldered in place. The
2471:
in the air reacts chemically with the hot filament or cathode, quickly ruining it. Designers developed tube designs that sealed reliably. This was why most tubes were constructed of glass. Metal alloys (such as
2078:
The generic name " valve" used in the UK derives from the unidirectional current flow allowed by the earliest device, the thermionic diode emitting electrons from a heated filament, by analogy with a non-return
1214:
in 1919. He showed that the addition of an electrostatic shield between the control grid and the plate could solve the problem. This design was refined by Hull and
Williams. The added grid became known as the
1287:
of the pentode was usually connected to the cathode and its negative voltage relative to the anode repelled secondary electrons so that they would be collected by the anode instead of the screen grid. The term
970:
process in Berlin, Germany. Tigerstedt's innovation was to make the electrodes concentric cylinders with the cathode at the centre, thus greatly increasing the collection of emitted electrons at the anode.
1240:
The useful region of operation of the screen grid tube (tetrode) as an amplifier is limited to anode potentials in the straight portions of the characteristic curves greater than the screen grid potential.
2016:
The screen grid may also generate considerable heat. Limits to screen grid dissipation, in addition to plate dissipation, are listed for power devices. If these are exceeded then tube failure is likely.
2439:" by gas molecules from other elements in the tube, which reduce its ability to emit electrons. Trapped gases or slow gas leaks can also damage the cathode or cause plate (anode) current runaway due to
702:, such tubes were only used in scientific research or as novelties. The groundwork laid by these scientists and inventors, however, was critical to the development of subsequent vacuum tube technology.
2083:
in a water pipe. The US names "vacuum tube", "electron tube", and "thermionic tube" all simply describe a tubular envelope which has been evacuated ("vacuum"), has a heater and controls electron flow.
3377:
Every tube has a unique set of such characteristic curves. The curves graphically relate the changes to the instantaneous plate current driven by a much smaller change in the grid-to-cathode voltage (
2584:
Getters act by chemically combining with residual or infiltrating gases, but are unable to counteract (non-reactive) inert gases. A known problem, mostly affecting valves with large envelopes such as
2037:
Triode tube type GS-9B; designed for use at radio frequencies up to 2000 MHz and rated for 300 watts anode power dissipation. The finned heat sink provides conduction of heat from anode to air stream.
630:
in klystrons) at ground potential to facilitate cooling, particularly with water, without high-voltage insulation. These tubes instead operate with high negative voltages on the filament and cathode.
616:
through the glass envelope. In some special high power applications, the anode forms part of the vacuum envelope to conduct heat to an external heat sink, usually cooled by a blower, or water-jacket.
4905:
2725:
Tubes on standby for long periods, with heater voltage applied, may develop high cathode interface resistance and display poor emission characteristics. This effect occurred especially in pulse and
1048:) is defined as the change in the plate(anode)/cathode current divided by the corresponding change in the grid to cathode voltage, with a constant plate(anode) to cathode voltage. Typical values of
791:
as scientific advisor in 1899. Fleming had been engaged as scientific advisor to Edison
Telephone (1879), as scientific advisor at Edison Electric Light (1882), and was also technical consultant to
2160:, after which the control electrode can no longer stop the current; the tube "latches" into conduction. Removing anode (plate) voltage lets the gas de-ionize, restoring its non-conductive state.
1364:". Octodes, such as the 7A8, were rarely used in the United States, but much more common in Europe, particularly in battery operated radios where the lower power consumption was an advantage.
240:
devices, which are smaller, safer, cooler, and more efficient, reliable, durable, and economical than thermionic tubes. Beginning in the mid-1960s, thermionic tubes were being replaced by the
2983:
devices in most amplifying, switching, and rectifying applications, there are certain exceptions. In addition to the special functions noted above, tubes still have some niche applications.
2793:
Most small signal vacuum tube devices have been superseded by semiconductors, but some vacuum tube electronic devices are still in common use. The magnetron is the type of tube used in all
2843:(CRT) is a vacuum tube used particularly for display purposes. Although there are still many televisions and computer monitors using cathode-ray tubes, they are rapidly being replaced by
2676:
pins. Stress may accumulate if a metal shield or other object presses on the tube envelope and causes differential heating of the glass. Glass may also be damaged by high-voltage arcing.
2204:
equipment may use a focused cathode and a rotating anode to dissipate the large amounts of heat thereby generated. These are housed in an oil-filled aluminum housing to provide cooling.
2397:
Where the mains voltage was in the 100–120 V range, this limited voltage proved suitable only for low-power receivers. Television receivers either required a transformer or could use a
1705:
Tubes designed for high gain audio applications may have twisted heater wires to cancel out stray electric fields, fields that could induce objectionable hum into the program material.
3625:
2699:
inside the tube, or by excess screen voltage. An arc inside the tube allows gas to evolve from the tube materials, and may deposit conductive material on internal insulating spacers.
2320:
power supplies became commonplace, some radio sets continued to be built with C batteries, as they would almost never need replacing. However more modern circuits were designed using
2175:; some can switch thousands of amperes. Thyratrons containing hydrogen have a very consistent time delay between their turn-on pulse and full conduction; they behave much like modern
1120:
5789:
1261:
which can itself cause instability. Another undesirable consequence of secondary emission is that screen current is increased, which may cause the screen to exceed its power rating.
2692:
if the filament sags, causing internal arcing. Excess heater-to-cathode voltage in indirectly heated cathodes can break down the insulation between elements and destroy the heater.
3331:. Due to the high voltage placed on the anode, a relatively small anode current can represent a considerable increase in energy over the value of the original signal voltage. The
2797:. In spite of the advancing state of the art in power semiconductor technology, the vacuum tube still has reliability and cost advantages for high-frequency RF power generation.
2013:, a good insulator, is required. Such systems usually have a built-in water-conductance monitor which will shut down the high-tension supply if the conductance becomes too high.
182:. It contains only a heated electron-emitting cathode and an anode. Electrons can flow in only one direction through the device—from the cathode to the anode. Adding one or more
2679:
Tube heaters may also fail without warning, especially if exposed to over voltage or as a result of manufacturing defects. Tube heaters do not normally fail by evaporation like
1833:). Colossus was able to break in a matter of hours messages that had previously taken several weeks; it was also much more reliable. Colossus was the first use of vacuum tubes
2062:
between the grid and the plate leads. Tube caps were also used for the plate (anode) connection, particularly in transmitting tubes and tubes using a very high plate voltage.
1658:
The earliest vacuum tubes strongly resembled incandescent light bulbs and were made by lamp manufacturers, who had the equipment needed to manufacture glass envelopes and the
1409:
The introduction of the miniature tube base (see below) which can have 9 pins, more than previously available, allowed other multi-section tubes to be introduced, such as the
522:. The principal reason for doing this was to avoid leakage resistance through the tube base, particularly for the high impedance grid input. The bases were commonly made with
5460:
Blank, M.; Borchard, P.; Cauffman, S.; Felch, K.; Rosay, M.; Tometich, L. (1 June 2013). "Experimental demonstration of a 527 GHZ gyrotron for dynamic nuclear polarization".
4485:
is the amount the signal at the control grid is increased in amplitude after passing through the tube, which is also referred to as the Greek letter μ (mu) or voltage gain (V
2931:), the single-photon detection capability of photomultiplier tubes makes this vacuum tube device excel in certain applications. Such a tube can also be used for detection of
1001:' and later the English type 'R' which were in widespread use by the allied military by 1916. Historically, vacuum levels in production vacuum tubes typically ranged from 10
2487:
is universally a sign of an overloaded tube. However, some large transmitting tubes are designed to operate with their anodes at red, orange, or in rare cases, white heat.
2066:
this cooling scheme are available up to 150 kW dissipation. Above that level, water or water-vapor cooling are used. The highest-power tube currently available is the
4429:
2745:
Vacuum tubes may develop defects in operation that make an individual tube unsuitable in a given device, although it may perform satisfactorily in another application.
2986:
In general, vacuum tubes are much less susceptible than corresponding solid-state components to transient overvoltages, such as mains voltage surges or lightning, the
2752:
loudspeaker. Leakage current between AC heaters and the cathode may couple into the circuit, or electrons emitted directly from the ends of the heater may also inject
2088:
3235:
In the early years of the 21st century there has been renewed interest in vacuum tubes, this time with the electron emitter formed on a flat silicon substrate, as in
2855:), although traditional analog scopes (dependent upon CRTs) continue to be produced, are economical, and preferred by many technicians. At one time many radios used "
2070:
4CM2500KG, a forced water-cooled power tetrode capable of dissipating 2.5 megawatts. By comparison, the largest power transistor can only dissipate about 1 kilowatt.
7513:
807:, but the magnetic detector only provided an audio frequency signal to a telephone receiver. A reliable detector that could drive a printing instrument was needed.
936:) for such a three-electrode version of his original Audion for use as an electronic amplifier in radio communications. This eventually became known as the triode.
1057:
for a small-signal vacuum tube are 1 to 10 millisiemens. It is one of the three 'constants' of a vacuum tube, the other two being its gain μ and plate resistance
2713:
Overheating of internal parts, such as control grids or mica spacer insulators, can result in trapped gas escaping into the tube; this can reduce performance. A
2263:
provided the voltages required by tubes in early radio sets. Three different voltages were generally required, using three different batteries designated as the
2625:
and emission begins to drop off rapidly; a complete loss of thorium has never been found to be a factor in the end-of-life in a tube with this type of emitter.
1894:) allowed the production of tubes that were reliable enough for the Whirlwind project. High-purity nickel tubing and cathode coatings free of materials such as
1367:
To further reduce the cost and complexity of radio equipment, two separate structures (triode and pentode for instance) can be combined in the bulb of a single
5652:
5338:, Fitzgerald, William V., "Power supply stabilization circuit with separate AC/DC negative feedback paths", published 1995-10-31, assigned to
3826:
2404:
Transformer-less power supplies required safety precautions in their design to limit the shock hazard to users, such as electrically insulated cabinets and an
4912:
1797:
1424:
electrodes which deflected the current towards either of two anodes. They were sometimes known as the 'sheet beam' tubes and used in some color TV sets for
2955:
consists of an array of single stage electron multipliers over an image plane; several of these can then be stacked. This can be used, for instance, as an
1244:
However, the useful region of operation of the screen grid tube as an amplifier was limited to plate voltages greater than the screen grid voltage, due to
6013:
2687:
when the heater is first energized causes stress in the heater and can be avoided by slowly warming the heaters, gradually increasing current with a NTC
1413:/ECF82 triode-pentode, quite popular in television receivers. The desire to include even more functions in one envelope resulted in the General Electric
1481:
grid, reducing control grid current. This design helps to overcome some of the practical barriers to designing high-power, high-efficiency power tubes.
267:, and amplifiers for electric musical instruments such as guitars (for desired effects, such as "overdriving" them to achieve a certain sound or tone).
3797:
2412:
was a power cord ending in the special socket used by the safety interlock; servicers could then power the device with the hazardous voltages exposed.
959:
were tested in the summer of 1913 on AT&T's long-distance network. The high-vacuum tubes could operate at high plate voltages without a blue glow.
225:
for computing, it was the invention of the thermionic vacuum tube that made these technologies widespread and practical, and created the discipline of
4315:
2597:
5948:
1177:
radio during the 1920s. However, neutralization required careful adjustment and proved unsatisfactory when used over a wide range of frequencies.
887:
In the 19th century, telegraph and telephone engineers had recognized the need to extend the distance that signals could be transmitted. In 1906,
6098:
5415:
1420:
Some otherwise conventional tubes do not fall into standard categories; the 6AR8, 6JH8 and 6ME8 have several common grids, followed by a pair of
189:
These devices became a key component of electronic circuits for the first half of the twentieth century. They were crucial to the development of
4996:
4863:. Proceedings of Symposium on Improved Quality Electronic Components. Vol. 1. Radio-Television Manufacturers Association. pp. 222–233.
4343:
4771:
3389:
The V-I characteristic depends upon the size and material of the plate and cathode. Express the ratio between voltage plate and plate current.
2087:
consumer tubes were given names that conveyed some information, with the same name often used generically by several manufacturers. In the US,
4455:
2157:
1402:
is a dual "high mu" (high voltage gain) triode in a miniature enclosure, and became widely used in audio signal amplifiers, instruments, and
119:, and are used for such purposes as the detection of light intensities. In both types, the electrons are accelerated from the cathode to the
5906:
Philips
Technical Library. Books published in the UK in the 1940s and 1950s by Cleaver Hume Press on design and application of vacuum tubes.
4158:
2408:
tying the power cord to the cabinet back, so the line cord was necessarily disconnected if the user or service person opened the cabinet. A
3990:
3072:
1378:
By 1940 multisection tubes had become commonplace. There were constraints, however, due to patents and other licensing considerations (see
1229:
to ground with a capacitor of low impedance at the frequencies to be amplified. This arrangement substantially decouples the plate and the
5380:
7148:
2532:
when struck by an electron and can adversely affect the cathode, reducing emission. Larger amounts of residual gas can create a visible
1997:
may also use a shiny metal anode since the gas present inside the tube allows for heat convection from the anode to the glass enclosure.
5059:
2884:
effect, due to the high voltage, is used for bunching the electrons. Gyrotrons can generate very high powers (hundreds of kilowatts).,
5991:
5766:
2760:
Tube pins can develop non-conducting or high resistance surface films due to heat or dirt. Pins can be cleaned to restore conductance.
2565:
being the most common. For glass tubes, while the tube envelope is being evacuated, the internal parts except the getter are heated by
4381:
4248:
6972:
5432:
4807:. Symposium on Commercially Available General-Purpose Electronic Digital Computers of Moderate Price. The Pentagon, Washington, D.C.
1394:
in early AC powered radios. These sets often include the 53 Dual Triode Audio Output. Another early type of multi-section tube, the
4075:
2943:
tube widely used in television studios prior to the development of modern CCD arrays also used multistage electron multiplication.
2483:
When a vacuum tube is overloaded or operated past its design dissipation, its anode (plate) may glow red. In consumer equipment, a
1755:(who operated telephone exchanges). Flowers was also a pioneer of using tubes as very fast (compared to electromechanical devices)
4360:
1708:
Heaters may be energized with either alternating current (AC) or direct current (DC). DC is often used where low hum is required.
6613:
5320:
4298:
3584:
3281:
As of 2014, NASA's Ames Research Center was reported to be working on vacuum-channel transistors produced using CMOS techniques.
2729:, where tubes had no plate current flowing for extended times. Tubes designed specifically for this mode of operation were made.
5633:"... geomagnetic storms, on occasion, can induce more powerful pulses than the E3 pulse from even megaton type nuclear weapons."
2892:, are highly relativistic vacuum tubes driven by high-energy particle accelerators. Thus, these are sorts of cathode-ray tubes.
1279:
The dynatron region of the screen grid tube was eliminated by adding a grid between the screen grid and the plate to create the
414:
Vacuum tubes may have other components and functions than those described above, and are described elsewhere. These include as
1398:, is a "dual triode" which performs the functions of two triode tubes while taking up half as much space and costing less. The
792:
2163:
Some thyratrons can carry large currents for their physical size. One example is the miniature type 2D21, often seen in 1950s
1206:
To combat the stability problems of the triode as a radio frequency amplifier due to grid-to-plate capacitance, the physicist
5875:
5477:
5053:
4753:
4741:
4475:
4412:
4097:
3695:
1922:
1830:
6062:
2816:, combine magnetic and electrostatic effects. These are efficient (usually narrow-band) RF generators and still find use in
2737:. Usable life of this expensive component was sometimes extended by fitting a boost transformer to increase heater voltage.
7431:
6530:
3498:
2401:
circuit. Where 230 V nominal mains voltage was used, television receivers as well could dispense with a power transformer.
2105:
5818:
5626:
3769:
3203:
2528:
vacuum, from X-ray terminology) to avoid the consequences of generating positive ions within the tube. Residual gas atoms
750:, such tubes were instrumental in long-distance telephony (such as the first coast-to-coast telephone line in the US) and
654:(JFET), although vacuum tubes typically operate at over a hundred volts, unlike most semiconductors in most applications.
6311:
6091:
3128:
2058:
the base of the tube, many early triodes connected the grid using a metal cap at the top of the tube; this reduces stray
4656:
4433:
4139:
4060:
3175:
2279:
or LT (low-tension) battery provided the filament voltage. Tube heaters were designed for single, double or triple-cell
5863:
5444:
4888:
4197:
3752:
3727:
3609:
3578:
1738:
Vacuum tubes used as switches made electronic computing possible for the first time, but the cost and relatively short
4016:
3919:
2390:. Many different US consumer AM radio manufacturers of the era used a virtually identical circuit, given the nickname
2225:, rather than thermionic emission, to generate and amplify electrical signals. Nuclear medicine imaging equipment and
6294:
6190:
5922:, RC15, RC26 (1947, 1968) Issued every two years, contains details of the technical specs of the tubes that RCA sold.
5853:
5569:
5263:
4681:
4238:
J.Jenkins and W.H.Jarvis, "Basic Principles of Electronics, Volume 1 Thermionics", Pergamon Press (1966), Ch.1.10 p.9
3851:
3820:
3222:
1945:
1641:
television tuners, and some HiFi FM radio tuners (Sansui 500A) until replaced by high-frequency capable transistors.
3976:
3251:). With these devices, electrons are field-emitted from a large number of closely spaced individual emission sites.
6434:
6161:
5911:
4543:
4045:
3671:
3602:
Fundamental Amplifier Techniques with Electron Tubes: Theory and Practice with Design Methods for Self Construction
3182:
1428:
875:
Triodes as they evolved over some 45 years of tube manufacture, from the RE16 in 1918 to a 1960s era miniature tube
651:
202:
5075:
2918:
whose sensitivity is greatly increased through the use of electron multiplication. This works on the principle of
2190:, which is used for rapid high-voltage switching. Krytrons are used to initiate the detonations used to set off a
330:, and so forth, which have multiple additional functions made possible by the additional controllable electrodes.
7141:
6482:
6281:
4029:
2183:
due to their functional similarity to thyratrons. Hydrogen thyratrons have long been used in radar transmitters.
5309:
5297:
5285:
5238:
5173:
4604:
4122:
2966:
electron optics of the wideband electron gun could not provide enough current to directly excite the phosphor.)
2880:
or vacuum masers, used to generate high-power millimeter band waves, are magnetic vacuum tubes in which a small
2200:
are used in medical imaging among other uses. X-ray tubes used for continuous-duty operation in fluoroscopy and
810:
As a result of experiments conducted on Edison effect bulbs, Fleming developed a vacuum tube that he termed the
7498:
7426:
6084:
5205:
4621:
3658:
3160:
2493:
The longest recorded valve life was earned by a Mazda AC/P pentode valve (serial No. 4418) in operation at the
1950:
1523:
vacuum tubes, though are always filled with gas at less than sea-level atmospheric pressure. Types such as the
186:
within the tube allows the current between the cathode and anode to be controlled by the voltage on the grids.
4976:
1078:
438:(which rely on electron flow through a vacuum where electron emission from the cathode depends on energy from
3875:
3493:
3189:
2928:
2226:
1717:
918:(anode), he discovered the ability of the resulting device to amplify signals. As the voltage applied to the
710:
5790:"The vacuum tube strikes back: NASA's tiny 460GHz vacuum transistor that could one day replace silicon FETs"
5732:
2435:
One reliability problem of tubes with oxide cathodes is the possibility that the cathode may slowly become "
6513:
6265:
5339:
3156:
2176:
2096:
electrodes, or two sets of electrodes in a single envelope—a double triode, for example). For example, the
1759:. Later work confirmed that tube unreliability was not as serious an issue as generally believed; the 1946
1548:
Miniature tube (right) compared to the older octal style. Not including pins, the larger tube, a 5U4GB, is
6048:
5710:
779:
At the end of the 19th century, radio or wireless technology was in an early stage of development and the
7508:
7503:
7493:
6317:
6254:
5614:
Broad, William J. "Nuclear Pulse (I): Awakening to the Chaos Factor", Science. 29 May 1981 212: 1009–1012
2852:
1033:
403:
275:
274:
are similar devices, but containing a gas, typically at low pressure, which exploit phenomena related to
6010:
3402:
AC plate resistance of the plate—resistance of the path between anode and cathode of alternating current
3171:
1264:
The otherwise undesirable negative resistance region of the plate characteristic was exploited with the
1225:. The screen grid is operated at a positive voltage significantly less than the plate voltage and it is
713:, it was Thomas Edison's apparently independent discovery of the phenomenon in 1883, referred to as the
7134:
6977:
6524:
2864:
1432:
906:
is credited with inventing the triode tube in 1907 while experimenting to improve his original (diode)
5412:
5335:
3030:
provide amplification at power levels unattainable using current semiconductor devices. The household
2702:
Tube rectifiers have limited current capability and exceeding ratings will eventually destroy a tube.
2516:
2350:
Battery replacement was a major operating cost for early radio receiver users. The development of the
2171:. A cold-cathode version of the thyratron, which uses a pool of mercury for its cathode, is called an
1891:
754:, and introduced a far superior and versatile technology for use in radio transmitters and receivers.
7441:
6731:
6445:
6288:
6173:
4989:
3934:
Guarnieri, M. (2012). "The age of vacuum tubes: Early devices and the rise of radio communications".
3523:
3087:
prefer the distortion characteristics of vacuum tubes. Most popular vintage models use vacuum tubes.
2201:
1379:
947:
423:
4779:
2936:
375:
7488:
7290:
6740:
6598:
6450:
6306:
4467:
3399:
DC plate resistance of the plate—resistance of the path between anode and cathode of direct current
3075:, performance when overdriven, and ability to replicate prior-era tube-based recording are prized:
2922:, whereby a single electron emitted by the photocathode strikes a special sort of anode known as a
1325:
1272:
to oscillate. The dynatron oscillator operated on the same principle of negative resistance as the
943:
4189:
1236:
6751:
6471:
6270:
5829:
Basic theory and application of Electron tubes Department of the army and air force, AGO 2244-Jan
4154:
3244:
3149:
3119:
technology soon took the place of CRTs in these devices. By 2010, most CRT production had ended.
2980:
2680:
2405:
1202:
symbol. From top to bottom: plate (anode), screen grid, control grid, cathode, heater (filament).
1142:. Many early radio sets had a third battery called the "C battery" (unrelated to the present-day
531:
418:, which create a beam of electrons for display purposes (such as the television picture tube, in
237:
4558:
4065:. Annapolis, MD: United States Naval Institute. p. 124 fig. 84; pp. 131, 132. Retrieved Nov 2021
3994:
3885:
2296:
Most of the rest of the English speaking world refers to this supply as just HT (high tension).
2127:
Some special-purpose tubes are constructed with particular gases in the envelope. For instance,
1349:
1345:
7421:
6920:
6487:
6352:
6328:
3812:
Innovation and the Communications Revolution: From the Victorian Pioneers to Broadband Internet
3513:
3275:
3113:
3038:
tube to efficiently generate hundreds of watts of microwave power. Solid-state devices such as
2874:
is a type of cathode-ray tube that generates X-rays when high voltage electrons hit the anode.
2375:
2128:
2120:
2092:
1985:
from the anode (plate) as infrared radiation, and by convection of air over the tube envelope.
1524:
1387:
1293:
799:, a device that extracts information from a modulated radio frequency. Marconi had developed a
695:
5043:
4802:
2863:
to indicate signal strength or input level in a tape recorder. A modern indicator device, the
1825:(BP) during World War II to substantially speed up the task of breaking the German high level
583:) will convert alternating current (AC) to pulsating DC. Diodes can therefore be used in a DC
7483:
7320:
6989:
6941:
6762:
6578:
6493:
6424:
6260:
6026:—1972 AES paper on audible differences in sound quality between vacuum tubes and transistors.
4749:
3810:
3340:
on this negative value, driving it both positive and negative as the AC signal wave changes.
3239:
technology. This subject is now called vacuum nanoelectronics. The most common design uses a
2987:
2387:
2332:
2280:
2260:
2255:
2230:
1680:
982:
939:
751:
218:
135:
5977:
5758:
5221:
5124:
4459:
4181:
3841:
3327:
applied to the control grid, while the resulting amplified signal appears at the anode as a
2951:
and its ends were connected to enough voltage to create repeated cascades of electrons. The
2299:
1496:, and use a pentode graphic symbol instead of a graphic symbol showing beam forming plates.
1268:
circuit to produce a simple oscillator only requiring connection of the plate to a resonant
7457:
7436:
7416:
7355:
7295:
7221:
7063:
6807:
6702:
6476:
6369:
6223:
6184:
6115:
6107:
5675:
5584:
5514:
4377:
3518:
3487:
3015:
3006:
Vacuum tubes are practical alternatives to solid-state devices in generating high power at
2911:
2901:
2881:
2847:
whose quality has greatly improved even as their prices drop. This is also true of digital
2710:
Degenerative failures are those caused by the slow deterioration of performance over time.
2577:. Large transmitting and specialized tubes often use more exotic getter materials, such as
2218:
2214:
1982:
1911:
1878:
1852:
1768:
1739:
1638:
1421:
788:
772:
747:
720:
613:
527:
allowed by the base. There was even an occasional design that had two top cap connections.
435:
233:
179:
155:
116:
883:
Triode symbol. From top to bottom: plate (anode), control grid, cathode, heater (filament)
368:
8:
7380:
7269:
7171:
6783:
6691:
6583:
6419:
6396:
5915:, 1953 (4th Edition). Contains chapters on the design and application of receiving tubes.
5109:
4460:
4182:
3320:
3248:
3196:
3027:
2885:
2805:
2630:
2520:
Dead vacuum fluorescent display (Air has leaked in and the getter spot has become white.)
1818:
1752:
1383:
1337:
1318:
1265:
1258:
1128:
To use this range, a negative bias voltage had to be applied to the grid to position the
706:
592:
552:
538:
535:
523:
503:
443:
419:
364:
222:
92:
6071:
5925:
Shiers, George, "The First Electron Tube", Scientific American, March 1969, p. 104.
5679:
5588:
5518:
4263:
Guarnieri, M. (2012). "The age of vacuum tubes: the conquest of analog communications".
3879:
2557:
To prevent gases from compromising the tube's vacuum, modern tubes are constructed with
2343:"Cheater cord" redirects here. For the three-prong to two-prong mains plug adapter, see
803:, which was less responsive to natural sources of radio frequency interference than the
555:. This can produce a controllable unidirectional current though the vacuum known as the
381:
by application (receiving, transmitting, amplifying or switching, rectification, mixing)
263:, and high end audio amplifiers, which many audio enthusiasts prefer for their "warmer"
7088:
6948:
6656:
6623:
6439:
6323:
6301:
5930:
5691:
5545:
5502:
5483:
5157:
4707:
4574:
4357:
4280:
3951:
3466:
3236:
3042:
are promising replacements, but are very expensive and in early stages of development.
3019:
3011:
2952:
2932:
2919:
2844:
2351:
2234:
2222:
1477:
1245:
1207:
511:
44:
vacuum tubes, mostly miniature style, some with top cap connections for higher voltages
19:
This article is about the electronic device. For experiments in an evacuated pipe, see
5666:
Keeports, David (9 February 2017). "The warm, rich sound of valve guitar amplifiers".
5141:
3565:
2467:
Another important reliability problem is caused by air leakage into the tube. Usually
1914:
the tubes during offline maintenance periods to bring on early failure of weak units.
1417:
which has 12 pins. A typical example, the 6AG11, contains two triodes and two diodes.
1149:
Later circuits, after tubes were made with heaters isolated from their cathodes, used
7390:
7375:
7083:
7004:
6895:
6847:
6676:
6603:
6565:
6034:
5936:
5871:
5849:
5550:
5532:
5473:
5440:
5201:
5179:
5049:
4938:
4884:
4737:
4677:
4471:
4408:
4193:
3924:. London, UK: Marshall, Morgan & Scott, Ltd. pp. 136 - 143. Retrieved Nov. 2021.
3857:
3847:
3816:
3748:
3723:
3691:
3654:
3605:
3574:
2995:
2991:
2956:
2940:
2569:
2449:
2436:
2391:
2359:
2355:
1802:
1792:
1748:
1694:
1663:
1533:
1361:
1002:
888:
800:
784:
728:
608:
319:
6043:
5695:
5644:
5487:
4711:
4500:
4284:
3955:
2452:
filaments, but rarely do, since they operate at much lower temperatures than lamps.
1544:
7340:
7280:
6799:
6746:
6573:
6212:
5944:
5683:
5592:
5540:
5522:
5465:
5027:
4963:
4699:
4528:
4514:
4272:
3943:
3781:
3425:—Instrument for converting alternating electric currents into continuous currents (
3347:(see example above,) which visually display how the output current from the anode (
3109:
3101:
2840:
2834:
2734:
2622:
2585:
1965:
The anode (plate) of this transmitting triode has been designed to dissipate up to
1934:
1756:
1435:
1403:
1329:
1226:
1021:
978:
966:
significantly improved on the original triode design in 1914, while working on his
955:
892:
839:
796:
724:
623:
415:
407:
291:
245:
214:
65:
6608:
6039:
5597:
5018:, J. L. Heilbron, Oxford University Press 2003, 9780195112290, "valve, thermionic"
4589:
4090:
3649:
John Algeo, "Types of English heteronyms", p. 23 in, Edgar Werner Schneider (ed),
2785:
Vacuum tubes can be tested outside of their circuitry using a vacuum tube tester.
1649:
7518:
7201:
7196:
7076:
7009:
6862:
6593:
6503:
6347:
6066:
6059:
5630:
5419:
5357:
5079:
4757:
4694:
Guarnieri, M. (2012). "The age of Vacuum Tubes: Merging with Digital Computing".
4660:
4364:
4214:
3538:
3112:
at the start of the 21st century. However, rapid advances and falling prices of
3083:
3079:
equipment, musical instrument amplifiers, and devices used in recording studios.
3065:
3039:
3007:
2726:
2659:
2651:
2566:
2398:
2010:
1772:
1675:
1508:
1469:
1333:
1284:
1036:, in which the controlling signal is a current and the output is also a current.
974:
963:
915:
817:
780:
687:
338:
271:
210:
6234:
6004:
5469:
4638:
4047:
Instrument for Converting Alternating Electric Currents into Continuous Currents
3411:
Size of electrostatic field is the size between two or more plates in the tube.
3274:
communication. As of 2012, they were being studied for possible applications in
2362:, reduced operating costs and contributed to the growing popularity of radio. A
1468:(or "beam power tube") forms the electron stream from the cathode into multiple
502:
in a vacuum inside an airtight envelope. Most tubes have glass envelopes with a
7360:
7335:
7051:
6832:
6822:
6588:
6391:
5687:
5623:
5381:"Remember when TVs weighed 200 pounds? A look back at TV trends over the years"
3790:
3507:
3308:
3031:
3022:. This is particularly true at microwave frequencies where such devices as the
2856:
2821:
2794:
2684:
2538:
2533:
2379:
2191:
2116:
1822:
1806:
1671:
1512:
1129:
990:
986:
399:
151:
124:
24:
5527:
5399:
1898:
and aluminum that can reduce emissivity also contribute to long cathode life.
1857:
835:
radio frequency current as the detector component of radio receiver circuits.
7477:
7400:
7395:
7285:
7206:
7176:
7113:
6936:
6852:
6671:
6498:
6466:
5536:
4703:
4653:
4276:
3947:
3900:
3441:
3433:
3426:
3421:
2655:
2484:
1907:
1840:
1826:
1814:
1744:
1162:
967:
932:
903:
861:
828:
735:
715:
683:
682:. The many scientists and inventors who experimented with such tubes include
675:
667:
557:
249:
175:
5981:; Van Valkenburgh, Nooger & Neville Inc.; John F. Rider Publisher; 1955.
5973:, Ziff Publishing, 1943, (reprint 1994 Prompt Publications), pp. 30–83.
4944:
4663:, Radio Constructor (See particularly the section "Glass Base Construction")
3861:
3785:
1829:. Colossus replaced an earlier machine based on relay and switch logic (the
783:
was engaged in development and construction of radio communication systems.
36:
7365:
7259:
7191:
7186:
6994:
6982:
6870:
6837:
6666:
6651:
6218:
5554:
5198:
Vacuum Technology Transactions: Proceedings of the Sixth National Symposium
5072:
3304:
3240:
2860:
2848:
2774:
2747:
2695:
2647:
2363:
2344:
2321:
1989:
is not possible inside most tubes since the anode is surrounded by vacuum.
1882:
1629:" (named due to its shape) was also very small, as was the metal-cased RCA
1516:
1473:
1465:
1456:
1447:
1391:
1353:
1298:
1273:
1230:
1150:
919:
691:
679:
674:
The 19th century saw increasing research with evacuated tubes, such as the
584:
541:
in an evacuated glass envelope. When hot, the filament in a vacuum tube (a
385:
183:
5940:
5255:
4141:
The Thermionic Valve and its Developments in Radiotelegraphy and Telephony
3970:
2974:
2054:
was a modern receiving tube using a very small metal and ceramic package.
356:
by power rating (small-signal, audio power, high-power radio transmitting)
7462:
7370:
7181:
7036:
6778:
6618:
6401:
6363:
3651:
Englishes Around the World: General studies, British Isles, North America
3533:
3475:
3446:
2809:
2779:
2769:
2428:
2367:
2059:
1926:
1862:
1659:
1605:
1425:
1217:
998:
600:
588:
515:
395:
391:
specialized functions (light or radiation detectors, video imaging tubes)
360:
298:
One classification of thermionic vacuum tubes is by the number of active
286:
226:
100:
96:
6076:
4091:"Robert von Lieben — Patent Nr 179807 Dated November 19, 1906"
2424:
1292:
means the tube has five electrodes. The pentode was invented in 1926 by
142:
7385:
7315:
7305:
7300:
7244:
7108:
7098:
7031:
6905:
6875:
6842:
6817:
6812:
6789:
6661:
6641:
6519:
6381:
6358:
6244:
6146:
6141:
6136:
6017:
3528:
3503:
3163: in this section. Unsourced material may be challenged and removed.
3116:
3105:
3076:
3071:
Tube amplifiers remain commercially viable in three niches where their
3055:
2871:
2688:
2589:
2529:
2457:
2440:
2312:
2304:
2197:
2148:
1986:
1626:
1414:
1269:
1174:
699:
662:
427:
299:
264:
241:
217:. Although some applications had used earlier technologies such as the
194:
41:
28:
6020:. Fleming discovers the thermionic (or oscillation) valve, or 'diode'.
5462:
2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)
1536:
vapor to achieve a lower forward voltage drop than high-vacuum tubes.
954:
plate voltage was high (above about 60 volts). In 1912, de Forest and
482:
270:
Not all electronic circuit valves or electron tubes are vacuum tubes.
255:
Thermionic tubes are still employed in some applications, such as the
130:
7350:
7345:
7325:
7071:
6915:
6910:
6900:
6827:
6707:
6541:
6536:
6461:
6386:
3271:
3259:
3255:
3035:
2962:
2915:
2801:
2753:
2683:
filaments since they operate at much lower temperature. The surge of
2617:
2578:
2371:
2328:
2327:
The "C battery" for bias is a designation having no relation to the "
2303:
Three-battery array powering a vacuum-tube circuit (highlighting the
2288:
2276:
2180:
2152:
2132:
2123:
in operation. Low-pressure gas within tube glows due to current flow.
1994:
1961:
1594:
1528:
1372:
1143:
1138:
927:
832:
579:
574:
499:
459:
431:
350:
315:
307:
260:
256:
206:
112:
108:
104:
73:
20:
7126:
4184:
Radio Engineering for Wireless Communication and Sensor Applications
3884:. London and Glasgow: William Collins, Sons, & Company. p.
3138:
2291:
or the HT (high-tension) supply or battery. These were generally of
1775:(one of the first commercially available electronic computers), and
166:) that would be included in series with the C and B voltage sources.
7330:
7310:
7249:
7093:
7041:
7021:
6999:
6885:
6880:
6768:
6757:
6686:
6456:
6023:
3688:
The Penguin Encyclopedia of Modern Warfare: 1850 to the present day
3543:
3460:
3314:
3023:
2877:
2813:
2609:
2593:
2292:
2172:
2051:
1895:
1874:
1776:
1630:
1610:
1589:
1075:. The Van der Bijl equation defines their relationship as follows:
856:
619:
548:
163:
159:
3319:
All tubes with one or more control grids are controlled by an AC (
2287:
The high voltage applied to the anode (plate) was provided by the
1941:
calculators, and was designated as a general-purpose triode tube.
1846:
1024:
devices, in which the controlling signal applied to the grid is a
7264:
7254:
6953:
6890:
6712:
6697:
6551:
6508:
6156:
3676:. New York: W. W. Norton & Co. Inc. p. 58. Retrieved Oct 2021
2646:
Cathodes in small "receiving" tubes are coated with a mixture of
2626:
2613:
2505:
2477:
2187:
2164:
2046:
2041:
Most modern tubes have glass envelopes, but metal, fused quartz (
1938:
1870:
1801:
Vacuum tubes seen on end in a recreation of the World War II-era
1634:
1597:, in higher-power audio output stages and as transmitting tubes.
1357:
1280:
1199:
1190:
1186:
1028:, and the resulting amplified signal appearing at the anode is a
911:
804:
768:
643:
639:
577:. Since current can only pass in one direction, such a diode (or
543:
519:
469:
327:
323:
77:
5183:
4734:
Colossus: The Secrets of Bletchley Park's Codebreaking Computers
4732:
Copeland, B. Jack (2006). "Chapter 5: Machine against Machine".
4144:. London, UK: The Wireless Press Ltd. p. 115. Retrieved Oct 2021
3356:) can be affected by a small input voltage applied on the grid (
1877:
alloy to make the heater wire easier to draw. The silicon forms
1813:
Colossus I and its successor Colossus II (Mk2) were designed by
1532:
they do perform electronic functions. High-power rectifiers use
7275:
7239:
7234:
7211:
7026:
6717:
6681:
6646:
6206:
6178:
6151:
6126:
5162:, San Carlos, CA: CPI, EIMAC Div., p. 68. Retrieved 25 Oct 2021
5114:
New York: General Electric Review. p. 174. Retrieved Nov. 2021
4062:
Manual of Wireless Telegraphy for the use of Naval Electricians
3770:"Triode amplifiers in the frequency range 100 Mc/s to 420 Mc/s"
3481:
3289:
3000:
2923:
2905:
2714:
2574:
2562:
2558:
2509:
2473:
2468:
2444:
2140:
2042:
1944:
The tubes developed for Whirlwind were later used in the giant
1921:, also labeled as E180CC. This, according to a memorandom from
1667:
1644:
1341:
907:
897:
864:
851:
838:
While offering no advantage over the electrical sensitivity of
743:
739:
635:
488:
439:
388:
and low-noise audio amplification, rugged or military versions)
311:
147:
69:
6054:
4946:
Technical Manual TT-5 | Transmitting Tubes to 4 KW Plate Input
4548:, New York: McGraw-Hill, pp. 164 - 179. Retrieved 10 June 2021
4080:. London: The Wireless Press, Ltd. p. 74. Retrieved Nov. 2021.
3060:
1722:
1588:
Early tubes used a metal or glass envelope atop an insulating
1352:
have been used for this purpose. The additional grids include
1321:
contains five grids between the cathode and the plate (anode).
7103:
7014:
6773:
6546:
6339:
6201:
6196:
3484:—a solid-state, plug-compatible, replacement for vacuum tubes
3267:
3263:
3122:
2889:
2817:
2634:
2194:; krytrons are heavily controlled at an international level.
2168:
2136:
2097:
2080:
2067:
1764:
1760:
1727:
1557:
1399:
871:
823:
763:
570:
562:
507:
473:
465:
303:
198:
190:
171:
138:, the hot cathodes emitting their distinctive red-orange glow
120:
3686:
Macksey, Kenneth; Woodhouse, William (1991). "Electronics".
3278:
technology, but there were significant production problems.
2217:
is an extremely sensitive detector of light, which uses the
1340:
tube. Various alternatives such as using a combination of a
491:: voltage applied to the grid controls plate (anode) current
374:
by characteristic curves design (e.g., sharp- versus remote-
7046:
6429:
6375:
6276:
6229:
6167:
5809:, Merlin Blencowe, Wem Publishing (2012), 978-0-9561545-2-1
5073:
National Valve Museum: audio double triodes ECC81, 2, and 3
4772:"A lost interview with ENIAC co-inventor J. Presper Eckert"
2144:
2002:
1918:
1902:
1887:
1881:
at the interface between the nickel sleeve and the cathode
1410:
1395:
1020:
The triode and its derivatives (tetrodes and pentodes) are
1010:
910:. By placing an additional electrode between the filament (
5645:"The cool sound of tubes—vacuum tube musical applications"
5500:
5459:
5178:, Indianapolis, Indiana, USA: Howard W. Sams, p. 23,
4835:
4823:
3745:
Electronics: A General Introduction for the Non-Specialist
2025:
1666:'s mercury displacement pump, which left behind a partial
1313:
1195:
1039:
For vacuum tubes, transconductance or mutual conductance (
6029:
4951:
4811:
4628:, New York: RCA Institutes Technical Press, pp. 101 - 108
2494:
2374:(which may themselves be vacuum tubes), and large filter
1930:
1679:
oxide-coated filaments in the mid-1920s reduced filament
1572:
1476:
region between the anode and screen grid to return anode
879:
831:, the oscillation valve was developed for the purpose of
346:
342:
6024:"Tubes Vs. Transistors: Is There an Audible Difference?"
5503:"A simplified description of X-ray free-electron lasers"
4299:"The Shielded Plate Valve as a High-Frequency Amplifier"
2959:
in which the discrete channels substitute for focusing.
2229:
use photomultiplier tube arrays to detect low-intensity
2033:
1452:
734:
Amplification by vacuum tube became practical only with
723:
applied the rectifying property of the Edison effect to
5430:
5004:
The maximum anode dissipation rating is 2500 kilowatts.
2975:
Industrial, commercial, and military niche applications
2633:
achieved 163,000 hours (18.6 years) of service from an
2089:
Radio Electronics Television Manufacturers' Association
2005:
is among the largest commercial tubes available today.
1308:
5577:
Physical Review Special Topics: Accelerators and Beams
4594:, Schenectady, NY: Tube Division, General Electric Co.
4462:
Handbook for Sound Engineers: The New Audio Cyclopedia
2939:(itself not an actual vacuum tube). Historically, the
2888:, used to generate high-power coherent light and even
5501:
Margaritondo, G.; Rebernik Ribic, P. (1 March 2011).
5016:
The Oxford Companion to the History of Modern Science
3774:
Journal of the British Institution of Radio Engineers
1081:
248:(CRT) remained the basis for television monitors and
4559:"500-Mc. Transmitting Tetrode Design Considerations"
4253:. Washington D. C.: USGPO. p. 42. Retrieved Oct 2021
3456:
2979:
Although vacuum tubes have been largely replaced by
1662:
required to evacuate the enclosures. de Forest used
997:
Pliotrons were closely followed by the French type '
795:. One of Marconi's needs was for improvement of the
5807:
Designing Tube Preamps for Guitar and Bass, 2nd ed.
5090:
Certified by BBC central valve stores, Motspur Park
4906:
Memorandum M-2135: Some notes on current tube types
4378:"Philips Historical Products: Philips Vacuum Tubes"
3393:
V-I curve (Voltage across filaments, plate current)
3254:Such integrated microtubes may find application in
2969:
5651:. Vol. 35, no. 8. IEEE. pp. 24–35.
4943:
4937:
4247:Departments of the Army and the Air Force (1952).
4212:
3789:
1114:
4331:British Radio Valves The Classic Years: 1926-1946
3437:—Device for amplifying feeble electrical currents
2612:filaments containing a small trace (1% to 2%) of
2561:, which are usually metals that oxidize quickly,
2524:A vacuum tube needs an extremely high vacuum (or
603:invented the indirectly heated tube around 1913.
115:, however, achieve electron emission through the
7514:Telecommunications-related introductions in 1904
7475:
4358:Introduction to Thermionic Valves (Vacuum Tubes)
4053:
3685:
3478:—close to manufacturer's stated parameter values
3315:Voltage - Current characteristics of vacuum tube
3297:
2859:", a specialized sort of CRT used in place of a
259:used in microwave ovens, certain high-frequency
5759:"Vacuum tubes could be the future of computing"
5321:Analogue Oscilloscope: cathode ray oscilloscope
4881:AN/FSQ-7: The Computer that Shaped the Cold War
3914:
3912:
3910:
1730:computer used 17,468 vacuum tubes and consumed
1576:Subminiature CV4501 tube (SQ version of EF72),
1484:Manufacturer's data sheets often use the terms
742:" tube, a crude form of what was to become the
16:Device that controls current between electrodes
6035:O'Neill's Electronic museum—vacuum tube museum
4250:Basic Theory and Application of Electron Tubes
3406:
3365:), for any given voltage on the plate(anode) (
2382:voltages from the alternating current source.
1956:
1901:The first such "computer tube" was Sylvania's
1711:
595:(AM) radio signals and for similar functions.
371:(including "bright-emitter" or "dull-emitter")
367:type (indirectly heated, directly heated) and
150:vacuum tube and the polarities of the typical
7142:
6092:
6051:—Data manual for tubes used in North America.
5959:, Vestal Press, New York, 1982, pp. 3–9.
5868:Station X: The Codebreakers of Bletchley Park
5413:Diagram of continuum and characteristic lines
4854:
4852:
4850:
4643:. Harrison, NJ: Tube Division, RCA. pp. 1,2,6
4179:
1687:
1431:. The similar 7360 was popular as a balanced
727:of radio signals, as an improvement over the
5570:"Review of x-ray free-electron laser theory"
5437:Principles of Modern Radar: Basic Principles
5424:
4990:"MULTI-PHASE COOLED POWER TETRODE 4CM2500KG"
4977:GS-9B Oscillator Ultra-High Frequency Triode
4096:. Kaiserliches Patentamt. 19 November 1906.
3907:
3396:Plate current, plate voltage characteristics
2788:
2104:A system widely used in Europe known as the
1917:Another commonly used computer tube was the
1837:on such a large scale for a single machine.
1645:Improvements in construction and performance
384:specialized parameters (long life, very low
5928:
5431:Richards, Mark A.; William A. Holm (2010).
5216:
5214:
4770:Randall, Alexander 5th (14 February 2006).
4727:
4725:
4723:
4721:
4698:. Vol. 6, no. 3. pp. 52–55.
4466:(1st ed.). Howard W. Sams Co. p.
4050:. U. S. patent 803,684. Retrieved Nov 2021.
3839:
2512:in opened tube; silvery deposit from getter
1974:types, red heat indicates severe overload.
1556:-diameter base, while the smaller, a 9-pin
930:. In 1908, de Forest was granted a patent (
7149:
7135:
6099:
6085:
5964:History of the British Radio Valve to 1940
5846:Colossus: Bletchley Park's Greatest Secret
5334:
5143:Principles and Practice of Radio Servicing
4930:
4858:
4847:
4676:, 4th ed. Newnes-Butterworth, London 1976
4077:Direction and Position Finding by Wireless
3123:Vacuum tubes using field electron emitters
2867:(VFD) is also a sort of cathode-ray tube.
657:
64:(North America) is a device that controls
6106:
5596:
5544:
5526:
5150:
5111:Production and Measurement of High Vacuum
5035:
4874:
4872:
4870:
4693:
4430:"Mu, Gm and Rp and how Tubes are matched"
4320:. New York: McGraw-Hill. pp. 3-34 - 3-38.
4262:
3933:
3343:This relationship is shown with a set of
3223:Learn how and when to remove this message
2608:Large transmitting tubes have carbonized
2208:
738:'s 1907 invention of the three-terminal "
302:. A device with two active elements is a
5665:
5610:
5608:
5567:
5350:
5211:
4911:(Report). MIT. p. 3. Archived from
4731:
4718:
4579:, San Carlos, CA: CPI, EIMAC Div., p. 28
4180:Räisänen, Antti V.; Lehto, Arto (2003).
4155:"AT&T Labs Research | AT&T"
3904:"Electrical Indicator", Issue date: 1884
3510:sometimes misidentified as a vacuum tube
3288:
3104:was the dominant display technology for
3059:
2773:
2705:
2670:
2515:
2504:
2423:
2298:
2115:
2111:
2032:
2024:
1960:
1856:
1796:
1721:
1648:
1604:
1571:
1543:
1451:
1312:
1235:
1194:
1180:
1115:{\displaystyle g_{m}={\mu \over R_{p}}}
938:
878:
870:
855:
767:
661:
285:
154:operating potentials. Not shown are the
141:
129:
111:. Non-thermionic types such as a vacuum
35:
5711:"Flat Panels Drive Old TVs From Market"
5642:
5041:
4861:Component failure analysis in computers
4769:
4736:. Oxford University Press. p. 72.
4622:"New Developments in Audio Power Tubes"
4323:
4215:"General Electric Research Lab History"
4123:"Birth of the Electron Tube Amplifier".
3874:
3713:
3711:
3604:. Elektor Electronics. 1 January 2011.
2895:
2311:Early sets used a grid bias battery or
1336:, combined in the function of a single
530:The earliest vacuum tubes evolved from
7476:
5843:
5796:from the original on 17 November 2015.
5002:from the original on 11 October 2016.
4878:
4867:
4841:
4829:
4800:
4454:
4308:
3767:
1600:
1032:. Compare this to the behavior of the
498:A vacuum tube consists of two or more
146:Illustration representing a primitive
7156:
7130:
6080:
6011:The invention of the thermionic valve
5862:
5605:
5561:
5378:
5239:"Getter Materials for Electron Tubes"
5228:, pp. 519 - 525 Retrieved 25 Oct 2021
5224:New Jersey: Electron Tube Div., RCA.
5171:
5127:New Jersey: Electron Tube Div., RCA.
4903:
4817:
4674:Electronics Engineer's Reference Book
4402:
3829:from the original on 3 December 2016.
3742:
3717:
3563:
3258:devices including mobile phones, for
2603:
1847:Whirlwind and "special-quality" tubes
6531:Three-dimensional integrated circuit
5756:
5708:
5655:from the original on 4 January 2012.
5175:Getting the Most out of Vacuum Tubes
5159:Care and Feeding of Power Grid Tubes
4794:
4696:IEEE Industrial Electronics Magazine
4576:Care and Feeding of Power Grid Tubes
4483:Amplification factor or voltage gain
4427:
4384:from the original on 6 November 2013
3808:
3708:
3293:Typical triode plate characteristics
3161:adding citations to reliable sources
3132:
2828:
2284:for the heaters had been developed.
2244:
1309:Multifunction and multisection tubes
6312:Programmable unijunction transistor
5966:, MMA International, 1982, pp 9–13.
5787:
5439:. SciTech Pub., 2010. p. 360.
5266:from the original on 20 August 2013
4859:Rich, E. S.; Taylor, N. H. (1950).
4161:from the original on 5 October 2013
3979:from the original on 18 August 2012
3564:Reich, Herbert J. (13 April 2013).
3129:Nanoscale vacuum-channel transistor
3095:
2370:with several windings, one or more
1861:Circuitry from core memory unit of
1503:
1441:
709:was originally reported in 1873 by
626:often operate their anodes (called
13:
6213:Multi-gate field-effect transistor
5957:70 Years of Radio Tubes and Valves
5886:
5769:from the original on 25 March 2013
5062:from the original on 22 June 2013.
4588:GE Electronic Tubes, (March 1955)
3653:, John Benjamins Publishing, 1997
3590:from the original on 2 April 2017.
3284:
3012:industrial radio frequency heating
2641:
2029:Metal-cased tubes with octal bases
1539:
551:into the vacuum, a process called
310:. Devices with three elements are
281:
14:
7530:
6191:Insulated-gate bipolar transistor
5998:
5340:Thomson Consumer Electronics Inc.
5245:pp. 80 - 86 Retrieved 25 Oct 2021
5099:Mazda Data Booklet 1968 Page 112.
4801:Jacobs, Donald H. (14 May 1952).
4603:J. F. Dreyer, Jr., (April 1936).
4557:Winfield G. Wagener, (May 1948).
3972:United States Early Radio History
3968:
2851:(based on internal computers and
2740:
2733:failure of monochrome television
2315:which was connected to provide a
1133:input voltage around that point.
6435:Heterostructure barrier varactor
6162:Chemical field-effect transistor
5823:
5812:
5800:
5781:
5750:
5507:Journal of Synchrotron Radiation
5237:Espe, Knoll, Wilder (Oct. 1950)
4611:, Vol. 9, No. 4, pp. 18 - 21, 35
4564:, p. 612. Retrieved 10 June 2021
4103:from the original on 28 May 2008
3846:. Tokyo: Ohmsha. pp. 7–25.
3670:Hoddeson L., Riordan M. (1997).
3499:Mullard–Philips tube designation
3459:
3245:large-area field electron source
3137:
2970:Vacuum tubes in the 21st century
2665:
2106:Mullard–Philips tube designation
2020:
652:junction field-effect transistor
481:
458:
203:sound recording and reproduction
23:. For the transport system, see
6483:Mixed-signal integrated circuit
5836:
5725:
5702:
5659:
5636:
5617:
5494:
5453:
5406:
5391:
5372:
5328:
5314:
5302:
5290:
5278:
5248:
5231:
5190:
5165:
5134:
5117:
5102:
5093:
5084:
5066:
5021:
5009:
4982:
4970:
4897:
4763:
4687:
4666:
4646:
4631:
4614:
4597:
4582:
4567:
4551:
4536:
4522:
4508:
4494:
4448:
4421:
4396:
4370:
4351:
4336:
4314:Landee, Davis, Albrecht (1957)
4291:
4256:
4241:
4232:
4206:
4173:
4147:
4132:
4115:
4083:
4068:
4038:
4022:
4009:
3983:
3962:
3927:
3892:
3868:
3833:
3802:
3148:needs additional citations for
2546:10 Torr; 130 μPa; 1.3
1779:, also available commercially.
1633:from 1959, about the size of a
1157:without requiring replacement.
322:. Additional electrodes create
232:In the 1940s, the invention of
6060:Characteristics and datasheets
6055:Vacuum tube data sheet locator
5978:Basic Electronics: Volumes 1–5
5624:Y Butt, The Space Review, 2011
5568:Huang, Z.; Kim, K. J. (2007).
5433:"Power Sources and Amplifiers"
5147:pp. 252. Retrieved 25 Oct 2021
5131:, p. 34. Retrieved 25 Oct 2021
4348:. New York: McGraw-Hill. p. 88
4333:, Reading, UK: Speedwell, p. 3
4317:Electronic Designers' Handbook
4121:F. B. Llewellyn. (Mar. 1957).
3761:
3736:
3679:
3664:
3643:
3618:
3594:
3557:
3386:) as the input signal varies.
2419:
1173:and led to the success of the
746:. Being essentially the first
698:. With the exception of early
449:
252:until the early 21st century.
170:The simplest vacuum tube, the
1:
5929:Spangenberg, Karl R. (1948).
5912:Radiotron Designer's Handbook
5709:Wong, May (22 October 2006).
5598:10.1103/PhysRevSTAB.10.034801
4342:Happell, Hesselberth (1953).
3921:Memories of a Scientific Life
3626:"RCA Electron Tube 6BN6/6KS6"
3550:
3494:List of vacuum-tube computers
3445:—de Forest's three electrode
3345:Plate Characteristics curves,
3298:Space charge of a vacuum tube
3082:Many guitarists prefer using
2929:Single-photon avalanche diode
2654:, sometimes with addition of
2227:liquid scintillation counters
2177:silicon-controlled rectifiers
2151:at predictable voltages. The
1718:List of vacuum-tube computers
1276:oscillator many years later.
6514:Silicon controlled rectifier
6376:Organic light-emitting diode
6266:Diffused junction transistor
5903:, 2nd ed. McGraw-Hill, 1951.
5899:Millman, J. & Seely, S.
5894:Fundamentals of Vacuum Tubes
5403:. Priority date May 9, 1913.
5358:"How Computer Monitors Work"
4939:"Construction and Materials"
4605:"The Beam Power Output Tube"
4542:Donovan P. Geppert, (1951).
4432:. Välljud AB. Archived from
4035:p. 411. Retrieved Nov. 2021.
3743:Olsen, George Henry (2013).
3567:Principles of Electron Tubes
2853:analog-to-digital converters
2249:
1168:Eventually the technique of
787:appointed English physicist
278:, usually without a heater.
236:made it possible to produce
7:
7229:
6318:Static induction transistor
6255:Bipolar junction transistor
6207:MOS field-effect transistor
6179:Fin field-effect transistor
5470:10.1109/PLASMA.2013.6635226
5256:"The Klystron & Cactus"
4904:Frost, H. B. (4 May 1953).
4213:Edison Tech Center (2015).
4127:Radio & Television News
3573:. Literary Licensing, LLC.
3452:
3407:Size of electrostatic field
3090:
3049:
2338:
2209:§ Electron multipliers
1981:Heat escapes the device by
1957:Heat generation and cooling
1937:, primarily for use in the
1910:on the heater element, and
1786:
1712:Use in electronic computers
1674:in 1915 and improvement by
1472:to produce a low potential
1034:bipolar junction transistor
404:vacuum fluorescent displays
333:Other classifications are:
276:electric discharge in gases
178:), was invented in 1904 by
10:
7535:
6525:Static induction thyristor
6040:Vacuum tubes for beginners
5988:. UK reprint of the above.
5848:. London: Atlantic Books.
5418:February 23, 2008, at the
5196:C. Robert Meissner (ed.),
5048:. IOS Press. p. 133.
4752:, accessed 7 August 2024.
4640:6L6, 6L6-G Beam Power Tube
4620:R. S. Burnap (July 1936).
4591:6V6GT - 5V6GT Beam Pentode
4297:Beatty, R. T. (Oct. 1927)
3722:(4th ed.). Elsevier.
3414:
3126:
3053:
2899:
2865:vacuum fluorescent display
2832:
2767:
2763:
2342:
2253:
2206:
2186:A specialized tube is the
1850:
1790:
1715:
1688:Indirectly heated cathodes
1470:partially collimated beams
1445:
1371:. An early example is the
1184:
991:high-vacuum diffusion pump
849:
845:
761:
561:. A second electrode, the
472:flow towards the positive
27:. For blood sampling, see
18:
7450:
7409:
7272:(Hexode, Heptode, Octode)
7220:
7164:
7062:
6962:
6929:
6861:
6798:
6726:
6694:(Hexode, Heptode, Octode)
6632:
6564:
6446:Hybrid integrated circuit
6410:
6338:
6289:Light-emitting transistor
6243:
6125:
6114:
6030:The cathode-ray tube site
5986:Radio Designer's Handbook
5528:10.1107/S090904951004896X
5045:History of electron tubes
4562:Proceedings of the I.R.E.
3881:Magnetism and Electricity
3843:History of electron tubes
3840:Okamura, S., ed. (1994).
3747:. Springer. p. 391.
3524:Russian tube designations
2935:as an alternative to the
2789:Other vacuum tube devices
2588:and camera tubes such as
2500:
1670:. The development of the
1380:British Valve Association
1356:(at a low potential) and
1326:Superheterodyne receivers
948:Science History Institute
891:filed for a patent for a
757:
648:voltage-controlled device
468:: electrons from the hot
424:electron beam lithography
103:functions such as signal
7291:Backward-wave oscillator
6741:Backward-wave oscillator
6451:Light emitting capacitor
6307:Point-contact transistor
6277:Junction Gate FET (JFET)
5688:10.1088/1361-6552/aa57b7
4804:The JAINCOMP-B1 Computer
4704:10.1109/MIE.2012.2207830
4659:23 December 2015 at the
4277:10.1109/MIE.2012.2193274
4188:. Artech House. p.
3948:10.1109/MIE.2012.2182822
3490:—a list of type numbers.
3010:in applications such as
2941:image orthicon TV camera
2167:as control switches for
2073:
1210:invented the tetrode or
994:invalidated the patent.
944:General Electric Company
532:incandescent light bulbs
6752:Crossed-field amplifier
6271:Field-effect transistor
6065:13 January 2012 at the
5971:Saga of the Vacuum Tube
5241:New York: McGraw-Hill.
5125:"Oxide-Coated Emitters"
4407:. Newnes. p. 391.
4345:Engineering Electronics
4138:Fleming, J. A. (1919).
4059:Robison, S. S. (1911).
4044:Fleming, J. A. (1905).
3918:Fleming, J. A. (1934).
3786:10.1049/jbire.1951.0074
3690:. Viking. p. 110.
2443:of free gas molecules.
2129:voltage-regulator tubes
1136:This concept is called
1005:down to 10 nPa (8
658:History and development
386:microphonic sensitivity
7165:Theoretical principles
6921:Voltage-regulator tube
6488:MOS integrated circuit
6353:Constant-current diode
6329:Unijunction transistor
5819:indiastudychannel.com/
5078:7 January 2011 at the
5042:Okamura, Sōgo (1994).
4879:Ulmann, Bernd (2014).
4654:The Story of the Valve
4403:Baker, Bonnie (2008).
4329:K. R. Thrower, (2009)
4125:New York: Ziff-Davis.
3768:Rogers, D. C. (1951).
3718:Jones, Morgan (2012).
3514:RETMA tube designation
3294:
3276:field emission display
3068:
3020:broadcast transmitters
2782:
2521:
2513:
2432:
2378:provided the required
2308:
2124:
2121:Voltage-regulator tube
2038:
2030:
1970:
1865:
1810:
1735:
1655:
1621:
1585:
1569:
1525:voltage-regulator tube
1461:
1388:automatic gain control
1322:
1294:Bernard D. H. Tellegen
1241:
1203:
1125:approximately linear.
1116:
950:
884:
876:
868:
860:The first triode, the
776:
752:public address systems
696:Johann Wilhelm Hittorf
671:
394:tubes used to display
295:
167:
139:
134:Operating tubes in an
45:
7499:Electrical components
7321:Inductive output tube
6990:Electrolytic detector
6763:Inductive output tube
6579:Low-dropout regulator
6494:Organic semiconductor
6425:Printed circuit board
6261:Darlington transistor
6108:Electronic components
5920:Receiving Tube Manual
5844:Gannon, Paul (2006).
5629:22 April 2012 at the
5400:U.S. patent 1,203,495
5324:electronics-notes.com
5308:Tomer, R. B. (1960).
5296:Tomer, R. B. (1960).
5284:Tomer, R. B. (1960).
5220:Thomas, C. H. (1962)
5172:Tomer, R. B. (1960),
5123:Hadley, C. P. (1962)
4979:Archived 25 Feb. 2021
4883:. Walter de Gruyter.
4756:23 March 2012 at the
4748:Extract available at
4684:pages 7–2 through 7-6
4265:IEEE Ind. Electron. M
3936:IEEE Ind. Electron. M
3292:
3266:transmission, and in
3063:
3016:particle accelerators
2988:electromagnetic pulse
2777:
2706:Degenerative failures
2671:Catastrophic failures
2519:
2508:
2427:
2388:AC/DC receiver design
2356:batteryless receivers
2302:
2256:Battery (vacuum tube)
2119:
2112:Special-purpose tubes
2036:
2028:
1964:
1860:
1800:
1747:, who later designed
1725:
1681:operating temperature
1652:
1608:
1575:
1547:
1455:
1316:
1257:and is an example of
1239:
1198:
1181:Tetrodes and pentodes
1161:input), known as the
1117:
983:Schenectady, New York
981:research laboratory (
942:
882:
874:
859:
771:
665:
289:
234:semiconductor devices
219:spark gap transmitter
145:
136:audio power amplifier
133:
76:to which an electric
39:
7463:List of tube sockets
7458:List of vacuum tubes
7296:Beam deflection tube
6808:Beam deflection tube
6477:Metal-oxide varistor
6370:Light-emitting diode
6224:Thin-film transistor
6185:Floating-gate MOSFET
5992:"Vacuum Tube Design"
5892:Eastman, Austin V.,
5788:Anthony, Sebastian.
5643:Barbour, E. (1998).
5226:Electron Tube Design
5140:Hicks, H. J. (1943)
5129:Electron Tube Design
4844:, pp. 255, 284.
4832:, pp. 245, 246.
4820:, pp. 148, 149.
4545:Basic Electron Tubes
4219:edisontechcenter.org
4028:Editors (Sept 1954)
3794:on 27 February 2020.
3519:RMA tube designation
3488:List of vacuum tubes
3157:improve this article
3064:70-watt tube-hybrid
2902:Photomultiplier tube
2896:Electron multipliers
2886:Free-electron lasers
2806:traveling-wave tubes
2800:Some tubes, such as
2431:manufactured in 1930
2219:photoelectric effect
2215:photomultiplier tube
1983:black-body radiation
1929:, was developed for
1879:barium orthosilicate
1853:Whirlwind (computer)
1740:mean time to failure
1390:rectifier and audio
1386:used as a detector,
1297:applications is the
1079:
789:John Ambrose Fleming
748:electronic amplifier
721:John Ambrose Fleming
512:borosilicate glasses
476:, but not vice versa
337:by frequency range (
223:mechanical computers
180:John Ambrose Fleming
117:photoelectric effect
95:of electrons from a
83:The type known as a
78:potential difference
60:(British usage), or
7381:Traveling-wave tube
7172:Thermionic emission
6784:Traveling-wave tube
6584:Switching regulator
6420:Printed electronics
6397:Step recovery diode
6174:Depletion-load NMOS
6016:16 October 2012 at
6007:—FAQ from rec.audio
6005:The Vacuum Tube FAQ
5896:, McGraw-Hill, 1949
5870:. Channel 4 Books.
5680:2017PhyEd..52b5010K
5589:2007PhRvS..10c4801H
5519:2011JSynR..18..101M
5108:Dushman, S. (1922)
4652:C H Gardner (1965)
4428:Modjeski, Roger A.
4363:28 May 2007 at the
4030:"World of Wireless"
3901:U.S. patent 307,031
3809:Bray, John (2002).
3442:U.S. patent 879,532
3434:U.S. patent 841,387
3422:U.S. patent 803,684
3321:Alternating Current
3249:field emitter array
3028:traveling-wave tube
2845:flat panel displays
2631:Huntsville, Alabama
1819:General Post Office
1757:electronic switches
1601:Sub-miniature tubes
1384:double diode triode
1338:pentagrid converter
1319:pentagrid converter
1305:, discussed below.
1266:dynatron oscillator
1259:negative resistance
933:U.S. patent 879,532
707:thermionic emission
593:amplitude modulated
553:thermionic emission
524:phenolic insulation
504:glass-to-metal seal
444:thermionic emission
420:electron microscopy
306:, usually used for
93:thermionic emission
7509:Glass applications
7504:English inventions
7494:1904 in technology
7089:Crystal oscillator
6949:Variable capacitor
6624:Switched capacitor
6566:Voltage regulators
6440:Integrated circuit
6324:Tetrode transistor
6302:Pentode transistor
6295:Organic LET (OLET)
6282:Organic FET (OFET)
6049:NJ7P Tube Database
5738:. Veritas et Visus
5713:. AP via USA Today
5379:Katzmaier, David.
5187:Retrieved Oct 2021
4954:. 1962. p. 10
4750:the book's website
4672:L.W. Turner (ed.)
4367:, Colin J. Seymour
3876:Guthrie, Frederick
3467:Electronics portal
3295:
3237:integrated circuit
3069:
2996:geomagnetic storms
2992:nuclear explosions
2953:microchannel plate
2937:Geiger–Müller tube
2933:ionizing radiation
2920:secondary emission
2783:
2604:Transmitting tubes
2522:
2514:
2433:
2352:battery eliminator
2309:
2235:ionizing radiation
2223:secondary emission
2125:
2039:
2031:
1971:
1866:
1835:working in concert
1811:
1736:
1656:
1622:
1586:
1570:
1490:beam power pentode
1478:secondary emission
1462:
1323:
1246:secondary emission
1242:
1208:Walter H. Schottky
1204:
1163:Miller capacitance
1112:
951:
885:
877:
869:
867:, invented in 1906
777:
672:
670:experimental bulbs
573:, and is used for
296:
168:
140:
80:has been applied.
46:
7471:
7470:
7410:Numbering systems
7391:Video camera tube
7376:Talaria projector
7158:Thermionic valves
7124:
7123:
7084:Ceramic resonator
6896:Mercury-arc valve
6848:Video camera tube
6800:Cathode-ray tubes
6560:
6559:
6168:Complementary MOS
5877:978-0-7522-2189-2
5733:"The Standard TV"
5668:Physics Education
5479:978-1-4673-5171-3
5200:, Elsevier, 2016,
5055:978-90-5199-145-1
4743:978-0-19-957814-6
4477:978-0-672-21983-2
4414:978-0-7506-8627-3
4303:Wireless Engineer
4074:Keen, R. (1922).
3898:Thomas A. Edison
3697:978-0-670-82698-8
3243:in the form of a
3233:
3232:
3225:
3207:
3110:computer monitors
3008:radio frequencies
2957:image intensifier
2829:Cathode-ray tubes
2778:Universal vacuum
2735:cathode-ray tubes
2586:cathode-ray tubes
2570:induction heating
2550:10 mbar; 1.3
2450:incandescent lamp
2392:All American Five
2245:Powering the tube
1827:Lorenz encryption
1817:and built by the
1803:Colossus computer
1793:Colossus computer
1695:power transformer
1664:Heinrich Geissler
1584:(excluding leads)
1404:guitar amplifiers
1369:multisection tube
1362:All American Five
1110:
962:Finnish inventor
946:Pliotron, at the
889:Robert von Lieben
840:crystal detectors
812:oscillation valve
801:magnetic detector
785:Guglielmo Marconi
729:magnetic detector
711:Frederick Guthrie
609:quiescent current
416:cathode-ray tubes
400:"magic eye" tubes
378:in some pentodes)
294:with vacuum tubes
215:digital computers
7526:
7281:Cathode-ray tube
7151:
7144:
7137:
7128:
7127:
6978:electrical power
6863:Gas-filled tubes
6747:Cavity magnetron
6574:Linear regulator
6123:
6122:
6101:
6094:
6087:
6078:
6077:
6072:Tuning eye tubes
6044:Japanese Version
5984:Wireless World.
5962:Thrower, Keith,
5952:
5881:
5859:
5830:
5827:
5821:
5816:
5810:
5804:
5798:
5797:
5785:
5779:
5778:
5776:
5774:
5757:Ackerman, Evan.
5754:
5748:
5747:
5745:
5743:
5737:
5729:
5723:
5722:
5720:
5718:
5706:
5700:
5699:
5663:
5657:
5656:
5640:
5634:
5621:
5615:
5612:
5603:
5602:
5600:
5574:
5565:
5559:
5558:
5548:
5530:
5498:
5492:
5491:
5457:
5451:
5450:
5428:
5422:
5410:
5404:
5402:
5395:
5389:
5388:
5376:
5370:
5369:
5367:
5365:
5354:
5348:
5347:
5346:
5342:
5332:
5326:
5318:
5312:
5306:
5300:
5294:
5288:
5282:
5276:
5275:
5273:
5271:
5252:
5246:
5235:
5229:
5218:
5209:
5194:
5188:
5186:
5169:
5163:
5154:
5148:
5138:
5132:
5121:
5115:
5106:
5100:
5097:
5091:
5088:
5082:
5070:
5064:
5063:
5039:
5033:
5025:
5019:
5013:
5007:
5006:
5001:
4994:
4986:
4980:
4974:
4968:
4967:
4964:Internet Archive
4961:
4959:
4949:
4941:
4934:
4928:
4927:
4925:
4923:
4918:on 28 March 2021
4917:
4910:
4901:
4895:
4894:
4876:
4865:
4864:
4856:
4845:
4839:
4833:
4827:
4821:
4815:
4809:
4808:
4798:
4792:
4791:
4789:
4787:
4778:. Archived from
4767:
4761:
4747:
4729:
4716:
4715:
4691:
4685:
4670:
4664:
4650:
4644:
4635:
4629:
4618:
4612:
4601:
4595:
4586:
4580:
4571:
4565:
4555:
4549:
4540:
4534:
4526:
4520:
4512:
4506:
4498:
4492:
4491:
4465:
4452:
4446:
4445:
4443:
4441:
4436:on 21 March 2012
4425:
4419:
4418:
4400:
4394:
4393:
4391:
4389:
4374:
4368:
4355:
4349:
4340:
4334:
4327:
4321:
4312:
4306:
4295:
4289:
4288:
4260:
4254:
4245:
4239:
4236:
4230:
4229:
4227:
4225:
4210:
4204:
4203:
4187:
4177:
4171:
4170:
4168:
4166:
4151:
4145:
4136:
4130:
4119:
4113:
4112:
4110:
4108:
4102:
4095:
4087:
4081:
4072:
4066:
4057:
4051:
4042:
4036:
4026:
4020:
4013:
4007:
4006:
4004:
4002:
3993:. Archived from
3987:
3981:
3980:
3966:
3960:
3959:
3931:
3925:
3916:
3905:
3903:
3896:
3890:
3889:
3872:
3866:
3865:
3837:
3831:
3830:
3806:
3800:
3795:
3793:
3788:. Archived from
3765:
3759:
3758:
3740:
3734:
3733:
3720:Valve Amplifiers
3715:
3706:
3705:
3683:
3677:
3668:
3662:
3647:
3641:
3640:
3638:
3636:
3622:
3616:
3615:
3598:
3592:
3591:
3589:
3572:
3561:
3469:
3464:
3463:
3444:
3436:
3424:
3385:
3373:
3364:
3355:
3228:
3221:
3217:
3214:
3208:
3206:
3165:
3141:
3133:
3102:cathode-ray tube
3096:Cathode-ray tube
3084:valve amplifiers
2841:cathode-ray tube
2835:Cathode-ray tube
2757:better results.
2727:digital circuits
2623:tungsten carbide
2553:
2549:
2545:
2399:voltage doubling
2354:, and, in 1925,
2131:contain various
1968:
1951:submarine cables
1935:General Electric
1927:Project Whirwind
1733:
1620:
1616:
1583:
1579:
1567:
1563:
1555:
1551:
1509:Gas-filled tubes
1504:Gas-filled tubes
1442:Beam power tubes
1330:local oscillator
1212:screen grid tube
1121:
1119:
1118:
1113:
1111:
1109:
1108:
1096:
1091:
1090:
1074:
1065:
1056:
1047:
1022:transconductance
1016:
1008:
979:General Electric
956:John Stone Stone
935:
893:cathode-ray tube
485:
462:
436:photomultipliers
292:signal generator
272:Gas-filled tubes
246:cathode-ray tube
205:, long-distance
99:for fundamental
89:thermionic valve
66:electric current
7534:
7533:
7529:
7528:
7527:
7525:
7524:
7523:
7489:1904 in science
7474:
7473:
7472:
7467:
7446:
7432:Mullard–Philips
7405:
7356:Photomultiplier
7216:
7197:Suppressor grid
7160:
7155:
7125:
7120:
7058:
6973:audio and video
6958:
6925:
6857:
6794:
6722:
6703:Photomultiplier
6628:
6556:
6504:Quantum circuit
6412:
6406:
6348:Avalanche diode
6334:
6246:
6239:
6128:
6117:
6110:
6105:
6067:Wayback Machine
6001:
5969:Tyne, Gerald,
5935:. McGraw-Hill.
5889:
5887:Further reading
5884:
5878:
5856:
5839:
5834:
5833:
5828:
5824:
5817:
5813:
5805:
5801:
5792:. ExtremeTech.
5786:
5782:
5772:
5770:
5755:
5751:
5741:
5739:
5735:
5731:
5730:
5726:
5716:
5714:
5707:
5703:
5664:
5660:
5641:
5637:
5631:Wayback Machine
5622:
5618:
5613:
5606:
5572:
5566:
5562:
5499:
5495:
5480:
5458:
5454:
5447:
5429:
5425:
5420:Wayback Machine
5411:
5407:
5398:
5396:
5392:
5377:
5373:
5363:
5361:
5356:
5355:
5351:
5344:
5333:
5329:
5319:
5315:
5307:
5303:
5295:
5291:
5283:
5279:
5269:
5267:
5254:
5253:
5249:
5236:
5232:
5219:
5212:
5195:
5191:
5170:
5166:
5156:Staff, (2003).
5155:
5151:
5139:
5135:
5122:
5118:
5107:
5103:
5098:
5094:
5089:
5085:
5080:Wayback Machine
5071:
5067:
5056:
5040:
5036:
5031:radiomuseum.org
5026:
5022:
5014:
5010:
4999:
4992:
4988:
4987:
4983:
4975:
4971:
4957:
4955:
4936:
4935:
4931:
4921:
4919:
4915:
4908:
4902:
4898:
4891:
4877:
4868:
4857:
4848:
4840:
4836:
4828:
4824:
4816:
4812:
4799:
4795:
4785:
4783:
4782:on 2 April 2009
4768:
4764:
4758:Wayback Machine
4744:
4730:
4719:
4692:
4688:
4671:
4667:
4661:Wayback Machine
4651:
4647:
4636:
4632:
4619:
4615:
4602:
4598:
4587:
4583:
4573:Staff, (2003).
4572:
4568:
4556:
4552:
4541:
4537:
4532:radiomuseum.org
4527:
4523:
4518:radiomuseum.org
4513:
4509:
4504:radiomuseum.org
4499:
4495:
4488:
4478:
4453:
4449:
4439:
4437:
4426:
4422:
4415:
4405:Analog circuits
4401:
4397:
4387:
4385:
4376:
4375:
4371:
4365:Wayback Machine
4356:
4352:
4341:
4337:
4328:
4324:
4313:
4309:
4296:
4292:
4261:
4257:
4246:
4242:
4237:
4233:
4223:
4221:
4211:
4207:
4200:
4178:
4174:
4164:
4162:
4153:
4152:
4148:
4137:
4133:
4120:
4116:
4106:
4104:
4100:
4093:
4089:
4088:
4084:
4073:
4069:
4058:
4054:
4043:
4039:
4027:
4023:
4015:Fleming (1934)
4014:
4010:
4000:
3998:
3997:on 28 June 2013
3989:
3988:
3984:
3969:White, Thomas,
3967:
3963:
3932:
3928:
3917:
3908:
3899:
3897:
3893:
3873:
3869:
3854:
3838:
3834:
3823:
3807:
3803:
3780:(12): 569–575.
3766:
3762:
3755:
3741:
3737:
3730:
3716:
3709:
3698:
3684:
3680:
3669:
3665:
3648:
3644:
3634:
3632:
3624:
3623:
3619:
3612:
3600:
3599:
3595:
3587:
3581:
3570:
3562:
3558:
3553:
3548:
3539:Valve amplifier
3465:
3458:
3455:
3440:
3432:
3420:
3417:
3409:
3384:
3378:
3372:
3366:
3363:
3357:
3354:
3348:
3317:
3300:
3287:
3285:Characteristics
3247:(for example a
3229:
3218:
3212:
3209:
3166:
3164:
3154:
3142:
3131:
3125:
3098:
3093:
3066:audio amplifier
3058:
3052:
3040:gallium nitride
2977:
2972:
2912:photomultiplier
2908:
2900:Main articles:
2898:
2857:magic eye tubes
2837:
2831:
2822:microwave ovens
2795:microwave ovens
2791:
2772:
2766:
2743:
2708:
2673:
2668:
2660:aluminium oxide
2652:strontium oxide
2644:
2642:Receiving tubes
2606:
2598:image orthicons
2551:
2547:
2543:
2503:
2422:
2360:household power
2348:
2341:
2322:cathode biasing
2258:
2252:
2247:
2211:
2114:
2076:
2023:
2011:deionized water
1966:
1959:
1855:
1849:
1795:
1789:
1773:Ferranti Mark 1
1731:
1720:
1714:
1690:
1676:Irving Langmuir
1647:
1618:
1614:
1603:
1581:
1577:
1565:
1561:
1553:
1549:
1542:
1540:Miniature tubes
1513:discharge tubes
1506:
1494:beam power tube
1450:
1444:
1422:beam deflection
1311:
1303:beam power tube
1285:suppressor grid
1251:dynatron region
1193:
1185:Main articles:
1183:
1151:cathode biasing
1104:
1100:
1095:
1086:
1082:
1080:
1077:
1076:
1073:
1067:
1064:
1058:
1055:
1049:
1046:
1040:
1017:10 Torr).
1014:
1006:
985:) had improved
975:Irving Langmuir
964:Eric Tigerstedt
931:
854:
848:
781:Marconi Company
766:
760:
688:Eugen Goldstein
660:
534:, containing a
496:
495:
494:
493:
492:
486:
478:
477:
463:
452:
284:
282:Classifications
244:. However, the
85:thermionic tube
68:flow in a high
32:
17:
12:
11:
5:
7532:
7522:
7521:
7516:
7511:
7506:
7501:
7496:
7491:
7486:
7469:
7468:
7466:
7465:
7460:
7454:
7452:
7448:
7447:
7445:
7444:
7439:
7434:
7429:
7424:
7419:
7413:
7411:
7407:
7406:
7404:
7403:
7398:
7393:
7388:
7383:
7378:
7373:
7368:
7363:
7361:Selectron tube
7358:
7353:
7348:
7343:
7338:
7333:
7328:
7323:
7318:
7313:
7308:
7303:
7298:
7293:
7288:
7283:
7278:
7273:
7267:
7262:
7257:
7252:
7247:
7242:
7237:
7232:
7226:
7224:
7218:
7217:
7215:
7214:
7209:
7204:
7199:
7194:
7189:
7184:
7179:
7174:
7168:
7166:
7162:
7161:
7154:
7153:
7146:
7139:
7131:
7122:
7121:
7119:
7118:
7117:
7116:
7111:
7101:
7096:
7091:
7086:
7081:
7080:
7079:
7068:
7066:
7060:
7059:
7057:
7056:
7055:
7054:
7052:Wollaston wire
7044:
7039:
7034:
7029:
7024:
7019:
7018:
7017:
7012:
7002:
6997:
6992:
6987:
6986:
6985:
6980:
6975:
6966:
6964:
6960:
6959:
6957:
6956:
6951:
6946:
6945:
6944:
6933:
6931:
6927:
6926:
6924:
6923:
6918:
6913:
6908:
6903:
6898:
6893:
6888:
6883:
6878:
6873:
6867:
6865:
6859:
6858:
6856:
6855:
6850:
6845:
6840:
6835:
6833:Selectron tube
6830:
6825:
6823:Magic eye tube
6820:
6815:
6810:
6804:
6802:
6796:
6795:
6793:
6792:
6787:
6781:
6776:
6771:
6766:
6760:
6755:
6749:
6744:
6737:
6735:
6724:
6723:
6721:
6720:
6715:
6710:
6705:
6700:
6695:
6689:
6684:
6679:
6674:
6669:
6664:
6659:
6654:
6649:
6644:
6638:
6636:
6630:
6629:
6627:
6626:
6621:
6616:
6611:
6606:
6601:
6596:
6591:
6586:
6581:
6576:
6570:
6568:
6562:
6561:
6558:
6557:
6555:
6554:
6549:
6544:
6539:
6534:
6528:
6522:
6517:
6511:
6506:
6501:
6496:
6491:
6485:
6480:
6474:
6469:
6464:
6459:
6454:
6448:
6443:
6437:
6432:
6427:
6422:
6416:
6414:
6408:
6407:
6405:
6404:
6399:
6394:
6392:Schottky diode
6389:
6384:
6379:
6373:
6367:
6361:
6356:
6350:
6344:
6342:
6336:
6335:
6333:
6332:
6326:
6321:
6315:
6309:
6304:
6299:
6298:
6297:
6286:
6285:
6284:
6279:
6268:
6263:
6258:
6251:
6249:
6241:
6240:
6238:
6237:
6232:
6227:
6221:
6216:
6210:
6204:
6199:
6194:
6188:
6182:
6176:
6171:
6165:
6159:
6154:
6149:
6144:
6139:
6133:
6131:
6120:
6112:
6111:
6104:
6103:
6096:
6089:
6081:
6075:
6074:
6069:
6057:
6052:
6046:
6037:
6032:
6027:
6021:
6008:
6000:
5999:External links
5997:
5996:
5995:
5989:
5982:
5974:
5967:
5960:
5955:Stokes, John,
5953:
5926:
5923:
5916:
5907:
5904:
5897:
5888:
5885:
5883:
5882:
5876:
5864:Smith, Michael
5860:
5854:
5840:
5838:
5835:
5832:
5831:
5822:
5811:
5799:
5780:
5749:
5724:
5701:
5658:
5635:
5616:
5604:
5560:
5513:(2): 101–108.
5493:
5478:
5452:
5446:978-1891121524
5445:
5423:
5405:
5390:
5371:
5360:. 16 June 2000
5349:
5327:
5313:
5301:
5289:
5277:
5247:
5230:
5210:
5189:
5164:
5149:
5133:
5116:
5101:
5092:
5083:
5065:
5054:
5034:
5020:
5008:
4981:
4969:
4929:
4896:
4890:978-3486856705
4889:
4866:
4846:
4834:
4822:
4810:
4793:
4776:Computer World
4762:
4742:
4717:
4686:
4665:
4645:
4630:
4613:
4596:
4581:
4566:
4550:
4535:
4521:
4507:
4493:
4489:) of the tube.
4486:
4476:
4447:
4420:
4413:
4395:
4369:
4350:
4335:
4322:
4307:
4290:
4255:
4240:
4231:
4205:
4199:978-1580536691
4198:
4172:
4146:
4131:
4114:
4082:
4067:
4052:
4037:
4033:Wireless World
4021:
4008:
3991:"Mazda Valves"
3982:
3961:
3926:
3906:
3891:
3867:
3852:
3832:
3821:
3801:
3760:
3754:978-1489965356
3753:
3735:
3729:978-0080966403
3728:
3707:
3696:
3678:
3663:
3642:
3617:
3611:978-0905705934
3610:
3593:
3580:978-1258664060
3579:
3555:
3554:
3552:
3549:
3547:
3546:
3541:
3536:
3531:
3526:
3521:
3516:
3511:
3508:display device
3506:—a gas-filled
3501:
3496:
3491:
3485:
3479:
3472:
3471:
3470:
3454:
3451:
3450:
3449:
3438:
3430:
3416:
3413:
3408:
3405:
3404:
3403:
3400:
3397:
3394:
3382:
3370:
3361:
3352:
3316:
3313:
3309:electric field
3299:
3296:
3286:
3283:
3231:
3230:
3145:
3143:
3136:
3127:Main article:
3124:
3121:
3097:
3094:
3092:
3089:
3054:Main article:
3051:
3048:
3032:microwave oven
2976:
2973:
2971:
2968:
2897:
2894:
2861:meter movement
2833:Main article:
2830:
2827:
2790:
2787:
2768:Main article:
2765:
2762:
2742:
2741:Other failures
2739:
2707:
2704:
2685:inrush current
2672:
2669:
2667:
2664:
2643:
2640:
2605:
2602:
2554:10 atm).
2539:mean free path
2534:glow discharge
2502:
2499:
2421:
2418:
2380:direct current
2340:
2337:
2254:Main article:
2251:
2248:
2246:
2243:
2192:nuclear weapon
2179:, also called
2113:
2110:
2075:
2072:
2022:
2019:
1958:
1955:
1912:stress testing
1873:, used in the
1851:Main article:
1848:
1845:
1831:Heath Robinson
1823:Bletchley Park
1807:Bletchley Park
1791:Main article:
1788:
1785:
1713:
1710:
1689:
1686:
1672:diffusion pump
1646:
1643:
1619:11 mm diameter
1602:
1599:
1582:10 mm diameter
1541:
1538:
1519:tubes are not
1505:
1502:
1500:power output.
1446:Main article:
1443:
1440:
1310:
1307:
1182:
1179:
1170:neutralization
1107:
1103:
1099:
1094:
1089:
1085:
1071:
1062:
1053:
1044:
987:Wolfgang Gaede
900:vacuum tubes.
850:Main article:
847:
844:
762:Main article:
759:
756:
659:
656:
487:
480:
479:
464:
457:
456:
455:
454:
453:
451:
448:
412:
411:
392:
389:
382:
379:
372:
357:
354:
290:Radio station
283:
280:
209:networks, and
125:electric field
25:Pneumatic tube
15:
9:
6:
4:
3:
2:
7531:
7520:
7517:
7515:
7512:
7510:
7507:
7505:
7502:
7500:
7497:
7495:
7492:
7490:
7487:
7485:
7482:
7481:
7479:
7464:
7461:
7459:
7456:
7455:
7453:
7449:
7443:
7440:
7438:
7435:
7433:
7430:
7428:
7427:Marconi-Osram
7425:
7423:
7420:
7418:
7415:
7414:
7412:
7408:
7402:
7401:Fleming valve
7399:
7397:
7396:Williams tube
7394:
7392:
7389:
7387:
7384:
7382:
7379:
7377:
7374:
7372:
7369:
7367:
7364:
7362:
7359:
7357:
7354:
7352:
7349:
7347:
7344:
7342:
7339:
7337:
7334:
7332:
7329:
7327:
7324:
7322:
7319:
7317:
7314:
7312:
7309:
7307:
7304:
7302:
7299:
7297:
7294:
7292:
7289:
7287:
7284:
7282:
7279:
7277:
7274:
7271:
7268:
7266:
7263:
7261:
7258:
7256:
7253:
7251:
7248:
7246:
7243:
7241:
7238:
7236:
7233:
7231:
7228:
7227:
7225:
7223:
7219:
7213:
7210:
7208:
7207:Glowing anode
7205:
7203:
7200:
7198:
7195:
7193:
7190:
7188:
7185:
7183:
7180:
7178:
7177:Work function
7175:
7173:
7170:
7169:
7167:
7163:
7159:
7152:
7147:
7145:
7140:
7138:
7133:
7132:
7129:
7115:
7114:mercury relay
7112:
7110:
7107:
7106:
7105:
7102:
7100:
7097:
7095:
7092:
7090:
7087:
7085:
7082:
7078:
7075:
7074:
7073:
7070:
7069:
7067:
7065:
7061:
7053:
7050:
7049:
7048:
7045:
7043:
7040:
7038:
7035:
7033:
7030:
7028:
7025:
7023:
7020:
7016:
7013:
7011:
7008:
7007:
7006:
7003:
7001:
6998:
6996:
6993:
6991:
6988:
6984:
6981:
6979:
6976:
6974:
6971:
6970:
6968:
6967:
6965:
6961:
6955:
6952:
6950:
6947:
6943:
6940:
6939:
6938:
6937:Potentiometer
6935:
6934:
6932:
6928:
6922:
6919:
6917:
6914:
6912:
6909:
6907:
6904:
6902:
6899:
6897:
6894:
6892:
6889:
6887:
6884:
6882:
6879:
6877:
6874:
6872:
6869:
6868:
6866:
6864:
6860:
6854:
6853:Williams tube
6851:
6849:
6846:
6844:
6841:
6839:
6836:
6834:
6831:
6829:
6826:
6824:
6821:
6819:
6816:
6814:
6811:
6809:
6806:
6805:
6803:
6801:
6797:
6791:
6788:
6785:
6782:
6780:
6777:
6775:
6772:
6770:
6767:
6764:
6761:
6759:
6756:
6753:
6750:
6748:
6745:
6742:
6739:
6738:
6736:
6733:
6729:
6725:
6719:
6716:
6714:
6711:
6709:
6706:
6704:
6701:
6699:
6696:
6693:
6690:
6688:
6685:
6683:
6680:
6678:
6675:
6673:
6672:Fleming valve
6670:
6668:
6665:
6663:
6660:
6658:
6655:
6653:
6650:
6648:
6645:
6643:
6640:
6639:
6637:
6635:
6631:
6625:
6622:
6620:
6617:
6615:
6612:
6610:
6607:
6605:
6602:
6600:
6597:
6595:
6592:
6590:
6587:
6585:
6582:
6580:
6577:
6575:
6572:
6571:
6569:
6567:
6563:
6553:
6550:
6548:
6545:
6543:
6540:
6538:
6535:
6532:
6529:
6526:
6523:
6521:
6518:
6515:
6512:
6510:
6507:
6505:
6502:
6500:
6499:Photodetector
6497:
6495:
6492:
6489:
6486:
6484:
6481:
6478:
6475:
6473:
6470:
6468:
6467:Memtransistor
6465:
6463:
6460:
6458:
6455:
6452:
6449:
6447:
6444:
6441:
6438:
6436:
6433:
6431:
6428:
6426:
6423:
6421:
6418:
6417:
6415:
6409:
6403:
6400:
6398:
6395:
6393:
6390:
6388:
6385:
6383:
6380:
6377:
6374:
6371:
6368:
6365:
6362:
6360:
6357:
6354:
6351:
6349:
6346:
6345:
6343:
6341:
6337:
6330:
6327:
6325:
6322:
6319:
6316:
6313:
6310:
6308:
6305:
6303:
6300:
6296:
6293:
6292:
6290:
6287:
6283:
6280:
6278:
6275:
6274:
6272:
6269:
6267:
6264:
6262:
6259:
6256:
6253:
6252:
6250:
6248:
6242:
6236:
6233:
6231:
6228:
6225:
6222:
6220:
6217:
6214:
6211:
6208:
6205:
6203:
6200:
6198:
6195:
6192:
6189:
6186:
6183:
6180:
6177:
6175:
6172:
6169:
6166:
6163:
6160:
6158:
6155:
6153:
6150:
6148:
6145:
6143:
6140:
6138:
6135:
6134:
6132:
6130:
6124:
6121:
6119:
6116:Semiconductor
6113:
6109:
6102:
6097:
6095:
6090:
6088:
6083:
6082:
6079:
6073:
6070:
6068:
6064:
6061:
6058:
6056:
6053:
6050:
6047:
6045:
6041:
6038:
6036:
6033:
6031:
6028:
6025:
6022:
6019:
6015:
6012:
6009:
6006:
6003:
6002:
5993:
5990:
5987:
5983:
5980:
5979:
5975:
5972:
5968:
5965:
5961:
5958:
5954:
5950:
5946:
5942:
5938:
5934:
5933:
5927:
5924:
5921:
5917:
5914:
5913:
5908:
5905:
5902:
5898:
5895:
5891:
5890:
5879:
5873:
5869:
5865:
5861:
5857:
5855:1-84354-330-3
5851:
5847:
5842:
5841:
5826:
5820:
5815:
5808:
5803:
5795:
5791:
5784:
5768:
5764:
5760:
5753:
5734:
5728:
5712:
5705:
5697:
5693:
5689:
5685:
5681:
5677:
5674:(2): 025010.
5673:
5669:
5662:
5654:
5650:
5649:IEEE Spectrum
5646:
5639:
5632:
5628:
5625:
5620:
5611:
5609:
5599:
5594:
5590:
5586:
5583:(3): 034801.
5582:
5578:
5571:
5564:
5556:
5552:
5547:
5542:
5538:
5534:
5529:
5524:
5520:
5516:
5512:
5508:
5504:
5497:
5489:
5485:
5481:
5475:
5471:
5467:
5464:. p. 1.
5463:
5456:
5448:
5442:
5438:
5434:
5427:
5421:
5417:
5414:
5409:
5401:
5394:
5386:
5382:
5375:
5359:
5353:
5341:
5337:
5331:
5325:
5322:
5317:
5311:
5305:
5299:
5293:
5287:
5281:
5265:
5261:
5257:
5251:
5244:
5240:
5234:
5227:
5223:
5217:
5215:
5207:
5203:
5199:
5193:
5185:
5181:
5177:
5176:
5168:
5161:
5160:
5153:
5146:
5144:
5137:
5130:
5126:
5120:
5113:
5112:
5105:
5096:
5087:
5081:
5077:
5074:
5069:
5061:
5057:
5051:
5047:
5046:
5038:
5032:
5029:
5024:
5017:
5012:
5005:
4998:
4991:
4985:
4978:
4973:
4965:
4953:
4948:
4947:
4940:
4933:
4914:
4907:
4900:
4892:
4886:
4882:
4875:
4873:
4871:
4862:
4855:
4853:
4851:
4843:
4838:
4831:
4826:
4819:
4814:
4806:
4805:
4797:
4781:
4777:
4773:
4766:
4759:
4755:
4751:
4745:
4739:
4735:
4728:
4726:
4724:
4722:
4713:
4709:
4705:
4701:
4697:
4690:
4683:
4682:0-408-00168-2
4679:
4675:
4669:
4662:
4658:
4655:
4649:
4642:
4641:
4637:RCA, (1954).
4634:
4627:
4623:
4617:
4610:
4606:
4600:
4593:
4592:
4585:
4578:
4577:
4570:
4563:
4560:
4554:
4547:
4546:
4539:
4533:
4530:
4525:
4519:
4516:
4511:
4505:
4502:
4497:
4490:
4484:
4479:
4473:
4469:
4464:
4463:
4457:
4451:
4435:
4431:
4424:
4416:
4410:
4406:
4399:
4383:
4379:
4373:
4366:
4362:
4359:
4354:
4347:
4346:
4339:
4332:
4326:
4319:
4318:
4311:
4304:
4300:
4294:
4286:
4282:
4278:
4274:
4270:
4266:
4259:
4252:
4251:
4244:
4235:
4220:
4216:
4209:
4201:
4195:
4191:
4186:
4185:
4176:
4160:
4156:
4150:
4143:
4142:
4135:
4128:
4124:
4118:
4099:
4092:
4086:
4079:
4078:
4071:
4064:
4063:
4056:
4049:
4048:
4041:
4034:
4031:
4025:
4018:
4017:pp. 138 - 143
4012:
3996:
3992:
3986:
3978:
3974:
3973:
3965:
3957:
3953:
3949:
3945:
3941:
3937:
3930:
3923:
3922:
3915:
3913:
3911:
3902:
3895:
3887:
3883:
3882:
3877:
3871:
3863:
3859:
3855:
3853:90-5199-145-2
3849:
3845:
3844:
3836:
3828:
3824:
3822:9780852962183
3818:
3814:
3813:
3805:
3799:
3792:
3787:
3783:
3779:
3775:
3771:
3764:
3756:
3750:
3746:
3739:
3731:
3725:
3721:
3714:
3712:
3704:
3699:
3693:
3689:
3682:
3675:
3674:
3667:
3660:
3656:
3652:
3646:
3631:
3627:
3621:
3613:
3607:
3603:
3597:
3586:
3582:
3576:
3569:
3568:
3560:
3556:
3545:
3542:
3540:
3537:
3535:
3532:
3530:
3527:
3525:
3522:
3520:
3517:
3515:
3512:
3509:
3505:
3502:
3500:
3497:
3495:
3492:
3489:
3486:
3483:
3480:
3477:
3474:
3473:
3468:
3462:
3457:
3448:
3443:
3439:
3435:
3431:
3428:
3427:Fleming valve
3423:
3419:
3418:
3412:
3401:
3398:
3395:
3392:
3391:
3390:
3387:
3381:
3375:
3369:
3360:
3351:
3346:
3341:
3339:
3334:
3330:
3326:
3322:
3312:
3310:
3306:
3291:
3282:
3279:
3277:
3273:
3269:
3265:
3261:
3257:
3252:
3250:
3246:
3242:
3238:
3227:
3224:
3216:
3205:
3202:
3198:
3195:
3191:
3188:
3184:
3181:
3177:
3174: –
3173:
3172:"Vacuum tube"
3169:
3168:Find sources:
3162:
3158:
3152:
3151:
3146:This section
3144:
3140:
3135:
3134:
3130:
3120:
3118:
3115:
3111:
3107:
3103:
3088:
3085:
3080:
3078:
3074:
3067:
3062:
3057:
3047:
3043:
3041:
3037:
3033:
3029:
3025:
3021:
3017:
3013:
3009:
3004:
3002:
2997:
2993:
2989:
2984:
2982:
2967:
2964:
2960:
2958:
2954:
2948:
2944:
2942:
2938:
2934:
2930:
2925:
2921:
2917:
2913:
2907:
2903:
2893:
2891:
2887:
2883:
2879:
2875:
2873:
2868:
2866:
2862:
2858:
2854:
2850:
2849:oscilloscopes
2846:
2842:
2836:
2826:
2823:
2819:
2815:
2811:
2807:
2803:
2798:
2796:
2786:
2781:
2776:
2771:
2761:
2758:
2755:
2750:
2749:
2738:
2736:
2730:
2728:
2723:
2719:
2716:
2711:
2703:
2700:
2697:
2693:
2690:
2686:
2682:
2677:
2666:Failure modes
2663:
2661:
2657:
2656:calcium oxide
2653:
2649:
2639:
2636:
2632:
2628:
2624:
2619:
2615:
2611:
2601:
2599:
2595:
2591:
2587:
2582:
2580:
2576:
2571:
2568:
2564:
2560:
2555:
2540:
2535:
2531:
2527:
2518:
2511:
2507:
2498:
2496:
2491:
2488:
2486:
2485:glowing plate
2481:
2479:
2475:
2470:
2465:
2461:
2459:
2453:
2451:
2446:
2442:
2438:
2430:
2426:
2417:
2413:
2411:
2407:
2402:
2400:
2395:
2393:
2389:
2383:
2381:
2377:
2373:
2369:
2365:
2361:
2357:
2353:
2346:
2336:
2334:
2330:
2325:
2323:
2318:
2314:
2306:
2301:
2297:
2294:
2290:
2285:
2282:
2278:
2275:battery. The
2274:
2270:
2266:
2262:
2257:
2242:
2238:
2236:
2232:
2231:scintillation
2228:
2224:
2220:
2216:
2210:
2205:
2203:
2199:
2195:
2193:
2189:
2184:
2182:
2178:
2174:
2170:
2166:
2161:
2159:
2154:
2150:
2147:, which will
2146:
2142:
2138:
2134:
2130:
2122:
2118:
2109:
2107:
2102:
2099:
2094:
2090:
2084:
2082:
2071:
2069:
2063:
2061:
2055:
2053:
2048:
2044:
2035:
2027:
2021:Tube packages
2018:
2014:
2012:
2006:
2004:
1998:
1996:
1990:
1988:
1984:
1979:
1975:
1963:
1954:
1952:
1947:
1942:
1940:
1936:
1932:
1928:
1924:
1920:
1915:
1913:
1909:
1908:thermal shock
1904:
1899:
1897:
1893:
1889:
1884:
1880:
1876:
1872:
1864:
1859:
1854:
1844:
1842:
1841:Tommy Flowers
1838:
1836:
1832:
1828:
1824:
1820:
1816:
1815:Tommy Flowers
1808:
1804:
1799:
1794:
1784:
1780:
1778:
1774:
1770:
1766:
1762:
1758:
1754:
1750:
1746:
1745:Tommy Flowers
1741:
1729:
1724:
1719:
1709:
1706:
1703:
1699:
1696:
1685:
1682:
1677:
1673:
1669:
1665:
1661:
1651:
1642:
1640:
1636:
1632:
1628:
1613:" triode, c.
1612:
1607:
1598:
1596:
1591:
1574:
1559:
1546:
1537:
1535:
1530:
1526:
1522:
1518:
1514:
1510:
1501:
1497:
1495:
1491:
1487:
1482:
1479:
1475:
1471:
1467:
1458:
1454:
1449:
1439:
1437:
1436:(de)modulator
1434:
1430:
1427:
1423:
1418:
1416:
1412:
1407:
1405:
1401:
1397:
1393:
1389:
1385:
1381:
1376:
1374:
1370:
1365:
1363:
1359:
1355:
1354:control grids
1351:
1347:
1343:
1339:
1335:
1331:
1327:
1320:
1315:
1306:
1304:
1300:
1295:
1291:
1286:
1282:
1277:
1275:
1271:
1267:
1262:
1260:
1256:
1252:
1247:
1238:
1234:
1232:
1228:
1224:
1220:
1219:
1213:
1209:
1201:
1197:
1192:
1188:
1178:
1176:
1171:
1166:
1164:
1158:
1154:
1152:
1147:
1145:
1141:
1140:
1134:
1131:
1126:
1122:
1105:
1101:
1097:
1092:
1087:
1083:
1070:
1061:
1052:
1043:
1037:
1035:
1031:
1027:
1023:
1018:
1012:
1004:
1000:
995:
992:
988:
984:
980:
976:
972:
969:
968:sound-on-film
965:
960:
957:
949:
945:
941:
937:
934:
929:
928:amplification
923:
921:
917:
913:
909:
905:
904:Lee de Forest
901:
899:
894:
890:
881:
873:
866:
863:
858:
853:
843:
841:
836:
834:
830:
829:Fleming valve
826:
825:
820:
819:
813:
808:
806:
802:
798:
794:
790:
786:
782:
774:
770:
765:
755:
753:
749:
745:
741:
737:
736:Lee de Forest
732:
730:
726:
722:
718:
717:
716:Edison effect
712:
708:
703:
701:
697:
693:
689:
685:
684:Thomas Edison
681:
680:Crookes tubes
677:
669:
664:
655:
653:
649:
645:
641:
637:
631:
629:
625:
621:
617:
615:
610:
604:
602:
596:
594:
590:
586:
582:
581:
576:
575:rectification
572:
568:
564:
560:
559:
558:Edison effect
554:
550:
546:
545:
540:
537:
533:
528:
525:
521:
517:
513:
509:
505:
501:
490:
484:
475:
471:
467:
461:
447:
445:
441:
437:
433:
429:
425:
421:
417:
409:
405:
401:
397:
393:
390:
387:
383:
380:
377:
373:
370:
366:
362:
358:
355:
352:
348:
344:
340:
336:
335:
334:
331:
329:
325:
321:
317:
316:amplification
313:
309:
308:rectification
305:
301:
293:
288:
279:
277:
273:
268:
266:
262:
258:
253:
251:
250:oscilloscopes
247:
243:
239:
235:
230:
228:
224:
221:for radio or
220:
216:
212:
208:
204:
200:
196:
192:
187:
185:
184:control grids
181:
177:
176:Fleming valve
173:
165:
161:
157:
153:
149:
144:
137:
132:
128:
127:in the tube.
126:
122:
118:
114:
110:
109:rectification
106:
105:amplification
102:
98:
94:
90:
86:
81:
79:
75:
71:
67:
63:
59:
55:
54:electron tube
51:
43:
38:
34:
30:
26:
22:
7484:Vacuum tubes
7366:Storage tube
7260:Beam tetrode
7192:Control grid
7187:Space charge
7157:
6871:Cold cathode
6838:Storage tube
6728:Vacuum tubes
6727:
6677:Neutron tube
6652:Beam tetrode
6634:Vacuum tubes
6633:
6219:Power MOSFET
5994:; 1940; RCA.
5985:
5976:
5970:
5963:
5956:
5932:Vacuum Tubes
5931:
5919:
5910:
5900:
5893:
5867:
5845:
5837:Bibliography
5825:
5814:
5806:
5802:
5783:
5771:. Retrieved
5762:
5752:
5740:. Retrieved
5727:
5715:. Retrieved
5704:
5671:
5667:
5661:
5648:
5638:
5619:
5580:
5576:
5563:
5510:
5506:
5496:
5461:
5455:
5436:
5426:
5408:
5393:
5384:
5374:
5362:. Retrieved
5352:
5330:
5323:
5316:
5304:
5292:
5280:
5268:. Retrieved
5259:
5250:
5242:
5233:
5225:
5197:
5192:
5174:
5167:
5158:
5152:
5142:
5136:
5128:
5119:
5110:
5104:
5095:
5086:
5068:
5044:
5037:
5030:
5023:
5015:
5011:
5003:
4984:
4972:
4962:– via
4956:. Retrieved
4945:
4932:
4920:. Retrieved
4913:the original
4899:
4880:
4860:
4837:
4825:
4813:
4803:
4796:
4784:. Retrieved
4780:the original
4775:
4765:
4733:
4695:
4689:
4673:
4668:
4648:
4639:
4633:
4625:
4616:
4608:
4599:
4590:
4584:
4575:
4569:
4561:
4553:
4544:
4538:
4531:
4524:
4517:
4510:
4503:
4496:
4482:
4481:
4461:
4456:Ballou, Glen
4450:
4438:. Retrieved
4434:the original
4423:
4404:
4398:
4386:. Retrieved
4372:
4353:
4344:
4338:
4330:
4325:
4316:
4310:
4302:
4293:
4271:(2): 52–54.
4268:
4264:
4258:
4249:
4243:
4234:
4222:. Retrieved
4218:
4208:
4183:
4175:
4163:. Retrieved
4149:
4140:
4134:
4126:
4117:
4105:. Retrieved
4085:
4076:
4070:
4061:
4055:
4046:
4040:
4032:
4024:
4011:
3999:. Retrieved
3995:the original
3985:
3971:
3964:
3942:(1): 41–43.
3939:
3935:
3929:
3920:
3894:
3880:
3870:
3842:
3835:
3811:
3804:
3791:the original
3777:
3773:
3763:
3744:
3738:
3719:
3701:
3687:
3681:
3673:Crystal Fire
3672:
3666:
3650:
3645:
3633:. Retrieved
3629:
3620:
3601:
3596:
3566:
3559:
3410:
3388:
3379:
3376:
3367:
3358:
3349:
3344:
3342:
3337:
3333:space charge
3332:
3328:
3324:
3318:
3305:space charge
3301:
3280:
3253:
3241:cold cathode
3234:
3219:
3210:
3200:
3193:
3186:
3179:
3167:
3155:Please help
3150:verification
3147:
3099:
3081:
3070:
3044:
3005:
2985:
2978:
2961:
2949:
2945:
2909:
2882:relativistic
2876:
2869:
2838:
2810:Carcinotrons
2799:
2792:
2784:
2759:
2748:Microphonics
2746:
2744:
2731:
2724:
2720:
2712:
2709:
2701:
2694:
2678:
2674:
2648:barium oxide
2645:
2607:
2583:
2556:
2525:
2523:
2492:
2489:
2482:
2466:
2462:
2454:
2434:
2414:
2410:cheater cord
2409:
2403:
2396:
2384:
2364:power supply
2358:operated by
2349:
2345:Cheater plug
2333:battery size
2326:
2316:
2310:
2286:
2272:
2268:
2264:
2259:
2239:
2212:
2196:
2185:
2162:
2126:
2103:
2093:designations
2085:
2077:
2064:
2056:
2040:
2015:
2007:
1999:
1991:
1980:
1976:
1972:
1943:
1916:
1900:
1883:barium oxide
1867:
1839:
1834:
1812:
1781:
1737:
1707:
1704:
1700:
1691:
1660:vacuum pumps
1657:
1623:
1587:
1568:in diameter.
1552:high with a
1520:
1517:cold cathode
1507:
1498:
1493:
1489:
1486:beam pentode
1485:
1483:
1474:space charge
1466:beam tetrode
1463:
1457:Beam tetrode
1448:Beam tetrode
1429:demodulation
1419:
1408:
1392:preamplifier
1377:
1368:
1366:
1358:screen grids
1348:and even an
1324:
1302:
1299:beam tetrode
1289:
1278:
1274:tunnel diode
1263:
1255:tetrode kink
1254:
1250:
1243:
1231:control grid
1222:
1216:
1211:
1205:
1169:
1167:
1159:
1155:
1148:
1137:
1135:
1127:
1123:
1068:
1059:
1050:
1041:
1038:
1029:
1025:
1019:
996:
973:
961:
952:
924:
920:control grid
902:
886:
837:
822:
816:
811:
809:
778:
775:first diodes
733:
714:
704:
692:Nikola Tesla
673:
647:
632:
627:
618:
605:
597:
585:power supply
578:
566:
556:
542:
529:
497:
442:rather than
413:
369:warm-up time
332:
297:
269:
254:
231:
188:
169:
107:and current
88:
84:
82:
61:
57:
53:
49:
47:
33:
7371:Sutton tube
7182:Hot cathode
7037:Transformer
6779:Sutton tube
6619:Charge pump
6472:Memory cell
6402:Zener diode
6364:Laser diode
6247:transistors
6129:transistors
5901:Electronics
5310:pp. 30 - 33
5298:pp. 34 - 35
5286:pp. 17 - 20
5270:29 December
5243:Electronics
4958:10 December
4922:12 February
4842:Gannon 2006
4830:Gannon 2006
4609:Electronics
4224:12 November
3534:Tube tester
3476:Bogey value
3106:televisions
2981:solid-state
2780:tube tester
2770:Tube tester
2590:iconoscopes
2448:similar to
2429:Tube tester
2420:Reliability
2368:transformer
2313:"C" battery
2305:"C" battery
2289:"B" battery
2277:"A" battery
2198:X-ray tubes
2158:gas ionizes
2133:inert gases
2060:capacitance
1753:Post Office
1492:instead of
1223:shield grid
1218:screen grid
793:Edison-Swan
700:light bulbs
601:H. J. Round
589:demodulator
547:) releases
516:tube socket
450:Description
428:X-ray tubes
396:information
238:solid-state
227:electronics
97:hot cathode
50:vacuum tube
7478:Categories
7386:Trochotron
7316:Iconoscope
7306:Compactron
7301:Charactron
7245:Acorn tube
7109:reed relay
7099:Parametron
7032:Thermistor
7010:resettable
6969:Connector
6930:Adjustable
6906:Nixie tube
6876:Crossatron
6843:Trochotron
6818:Iconoscope
6813:Charactron
6790:X-ray tube
6662:Compactron
6642:Acorn tube
6599:Buck–boost
6520:Solaristor
6382:Photodiode
6359:Gunn diode
6355:(CLD, CRD)
6137:Transistor
6018:Archive-It
5773:8 February
5397:Coolidge,
5336:US 5463290
5206:1483223558
4818:Smith 1998
4626:RCA Review
4388:3 November
4001:12 January
3659:9027248761
3551:References
3529:Tube caddy
3504:Nixie tube
3183:newspapers
3117:flat panel
3077:audiophile
3073:warm sound
3056:Tube sound
2990:effect of
2872:X-ray tube
2802:magnetrons
2689:thermistor
2458:thermistor
2441:ionization
2376:capacitors
2372:rectifiers
2207:See also:
2202:CT imaging
2181:thyristors
1995:thyratrons
1987:Convection
1967:500 W
1953:possible.
1716:See also:
1627:acorn tube
1615:20 mm high
1609:RCA 6DS4 "
1595:rectifiers
1578:35 mm long
1415:Compactron
1328:require a
1270:LC circuit
1175:Neutrodyne
833:rectifying
628:collectors
624:magnetrons
500:electrodes
432:phototubes
300:electrodes
265:tube sound
261:amplifiers
242:transistor
213:and early
195:television
156:impedances
101:electronic
74:electrodes
42:thermionic
29:Vacutainer
7351:Phototube
7346:Monoscope
7341:Magnetron
7336:Magic eye
7326:Kinescope
7270:Pentagrid
7072:Capacitor
6916:Trigatron
6911:Thyratron
6901:Neon lamp
6828:Monoscope
6708:Phototube
6692:Pentagrid
6657:Barretter
6542:Trancitor
6537:Thyristor
6462:Memristor
6387:PIN diode
6164:(ChemFET)
5949:TK7872.V3
5717:8 October
5537:0909-0495
5364:4 October
5260:31 Alumni
5222:"Getters"
4165:21 August
3272:satellite
3260:Bluetooth
3256:microwave
3036:magnetron
2963:Tektronix
2916:phototube
2878:Gyrotrons
2814:klystrons
2594:orthicons
2579:zirconium
2406:interlock
2281:lead-acid
2261:Batteries
2250:Batteries
2165:jukeboxes
2153:thyratron
1896:silicates
1863:Whirlwind
1809:, England
1769:Whirlwind
1734:of power.
1726:The 1946
1564:high and
1529:thyratron
1460:and size.
1373:Loewe 3NF
1139:grid bias
1098:μ
1013:down to 8
862:de Forest
773:Fleming's
725:detection
705:Although
620:Klystrons
614:radiation
580:rectifier
549:electrons
510:sealable
506:based on
422:, and in
351:microwave
341:, radio,
320:switching
314:used for
257:magnetron
207:telephone
164:inductors
160:resistors
113:phototube
91:utilizes
21:Free fall
7451:Examples
7331:Klystron
7311:Eidophor
7286:Additron
7250:Nuvistor
7094:Inductor
7064:Reactive
7042:Varistor
7022:Resistor
7000:Antifuse
6886:Ignitron
6881:Dekatron
6769:Klystron
6758:Gyrotron
6687:Nuvistor
6604:Split-pi
6490:(MOS IC)
6457:Memistor
6215:(MuGFET)
6209:(MOSFET)
6181:(FinFET)
6063:Archived
6014:Archived
5866:(1998).
5794:Archived
5767:Archived
5696:21531107
5653:Archived
5627:Archived
5555:21335894
5488:31007942
5416:Archived
5264:Archived
5184:60-13843
5076:Archived
5060:Archived
4997:Archived
4786:25 April
4754:Archived
4712:41800914
4657:Archived
4458:(1987).
4440:22 April
4382:Archived
4361:Archived
4285:42357863
4159:Archived
4107:30 March
4098:Archived
3977:archived
3956:23351454
3878:(1876).
3862:30995577
3827:Archived
3635:13 April
3585:Archived
3544:Zetatron
3453:See also
3323:) input
3213:May 2018
3091:Displays
3050:In music
3024:klystron
2610:tungsten
2437:poisoned
2366:using a
2339:AC power
2317:negative
2293:dry cell
2173:ignitron
2135:such as
2091:(RETMA)
2052:nuvistor
1969:of heat.
1890:drawing
1875:tungsten
1787:Colossus
1777:UNIVAC I
1749:Colossus
1631:nuvistor
1611:nuvistor
1590:bakelite
1511:such as
1227:bypassed
1009:10
797:detector
676:Geissler
668:Edison's
536:filament
365:filament
328:pentodes
324:tetrodes
72:between
7442:Russian
7265:Pentode
7255:Tetrode
6995:Ferrite
6963:Passive
6954:Varicap
6942:digital
6891:Krytron
6713:Tetrode
6698:Pentode
6552:Varicap
6533:(3D IC)
6509:RF CMOS
6413:devices
6187:(FGMOS)
6118:devices
5742:12 June
5676:Bibcode
5585:Bibcode
5546:3042323
5515:Bibcode
5208:page 96
5145:2nd ed.
4129:. p. 44
3815:. IET.
3429:patent)
3415:Patents
3329:current
3325:voltage
3197:scholar
3034:uses a
2764:Testing
2627:WAAY-TV
2618:diffuse
2614:thorium
2559:getters
2478:Fernico
2233:due to
2188:krytron
2101:12AZ7.
2047:ceramic
1939:IBM 701
1871:silicon
1635:thimble
1566:20.4 mm
1534:mercury
1344:with a
1290:pentode
1283:. The
1281:pentode
1200:Tetrode
1191:Pentode
1187:Tetrode
1030:current
1026:voltage
977:at the
912:cathode
846:Triodes
805:coherer
666:One of
644:pentode
640:tetrode
587:, as a
544:cathode
520:top cap
470:cathode
440:photons
361:cathode
312:triodes
123:by the
7519:Vacuum
7276:Nonode
7240:Triode
7235:Audion
7212:Getter
7027:Switch
6718:Triode
6682:Nonode
6647:Audion
6527:(SITh)
6411:Other
6378:(OLED)
6340:Diodes
6291:(LET)
6273:(FET)
6245:Other
6193:(IGBT)
6170:(CMOS)
6157:BioFET
6152:BiCMOS
5947:
5941:567981
5939:
5874:
5852:
5694:
5553:
5543:
5535:
5486:
5476:
5443:
5345:
5204:
5182:
5052:
4887:
4740:
4710:
4680:
4474:
4411:
4305:p. 621
4283:
4196:
3954:
3860:
3850:
3819:
3751:
3726:
3703:radio.
3694:
3657:
3630:Amazon
3608:
3577:
3482:Fetron
3447:Audion
3199:
3192:
3185:
3178:
3170:
3018:, and
3001:MiG-25
2924:dynode
2906:Dynode
2890:X-rays
2812:, and
2715:getter
2696:Arcing
2596:, and
2575:oxygen
2563:barium
2530:ionize
2510:Getter
2501:Vacuum
2474:Cunife
2469:oxygen
2445:Vacuum
2329:C cell
2271:, and
2169:relays
2149:ionize
2141:helium
2045:) and
2043:silica
1771:, the
1732:150 kW
1668:vacuum
1654:right)
1350:octode
1346:hexode
1342:triode
1144:C cell
914:) and
908:Audion
898:triode
865:Audion
852:Triode
758:Diodes
744:triode
740:audion
694:, and
636:triode
539:sealed
489:Triode
376:cutoff
211:analog
174:(i.e.
148:triode
70:vacuum
40:Later
7422:RETMA
7230:Diode
7222:Types
7202:Anode
7104:Relay
7077:types
7015:eFUSE
6786:(TWT)
6774:Maser
6765:(IOT)
6754:(CFA)
6743:(BWO)
6667:Diode
6614:SEPIC
6594:Boost
6547:TRIAC
6516:(SCR)
6479:(MOV)
6453:(LEC)
6372:(LED)
6331:(UJT)
6320:(SIT)
6314:(PUT)
6257:(BJT)
6226:(TFT)
6202:LDMOS
6197:ISFET
5918:RCA.
5909:RCA.
5763:Dvice
5736:(PDF)
5692:S2CID
5573:(PDF)
5484:S2CID
5000:(PDF)
4993:(PDF)
4916:(PDF)
4909:(PDF)
4708:S2CID
4529:7360
4501:6AG11
4281:S2CID
4101:(PDF)
4094:(PDF)
3952:S2CID
3798:p.571
3588:(PDF)
3571:(PDF)
3338:rides
3268:radar
3264:Wi-Fi
3204:JSTOR
3190:books
2994:, or
2914:is a
2818:radar
2635:Eimac
2137:argon
2098:12AX7
2081:valve
2074:Names
2068:Eimac
1765:ENIAC
1761:ENIAC
1728:ENIAC
1562:45 mm
1560:, is
1558:12AX7
1554:35 mm
1550:93 mm
1426:color
1400:12AX7
1334:mixer
916:plate
824:anode
818:plate
764:Diode
571:diode
567:plate
563:anode
508:kovar
474:anode
466:Diode
339:audio
304:diode
199:radar
191:radio
172:diode
121:anode
58:valve
7047:Wire
7005:Fuse
6589:Buck
6442:(IC)
6430:DIAC
6366:(LD)
6235:UMOS
6230:VMOS
6147:PMOS
6142:NMOS
6127:MOS
5937:OCLC
5872:ISBN
5850:ISBN
5775:2013
5744:2008
5719:2006
5551:PMID
5533:ISSN
5474:ISBN
5441:ISBN
5385:CNET
5366:2009
5272:2013
5202:ISBN
5180:LCCN
5050:ISBN
5028:2D21
4960:2022
4924:2024
4885:ISBN
4788:2011
4738:ISBN
4678:ISBN
4515:6AR8
4472:ISBN
4442:2011
4409:ISBN
4390:2013
4226:2018
4194:ISBN
4167:2013
4109:2008
4003:2017
3858:OCLC
3848:ISBN
3817:ISBN
3749:ISBN
3724:ISBN
3692:ISBN
3655:ISBN
3637:2015
3606:ISBN
3575:ISBN
3270:and
3262:and
3176:news
3108:and
3100:The
3026:and
2904:and
2870:The
2839:The
2681:lamp
2650:and
2542:(1.0
2526:hard
2476:and
2221:and
2213:The
2145:neon
2003:8974
1946:SAGE
1925:for
1919:5965
1903:7AK7
1892:dies
1888:wire
1821:for
1767:and
1527:and
1521:hard
1515:and
1411:6GH8
1396:6SN7
1332:and
1317:The
1189:and
1011:Torr
678:and
622:and
434:and
408:CRTs
318:and
62:tube
7437:JIS
7417:RMA
6609:Ćuk
5945:LCC
5684:doi
5593:doi
5541:PMC
5523:doi
5466:doi
4952:RCA
4700:doi
4468:250
4273:doi
3944:doi
3782:doi
3374:).
3159:by
3114:LCD
2754:hum
2658:or
2629:in
2495:BBC
2143:or
1933:by
1931:IBM
1923:MIT
1805:at
1639:UHF
1617:by
1488:or
1433:SSB
1301:or
1253:or
1221:or
1066:or
1003:μPa
989:'s
591:of
565:or
446:).
426:);
359:by
347:UHF
343:VHF
162:or
87:or
7480::
6983:RF
6732:RF
5943:.
5765:.
5761:.
5690:.
5682:.
5672:52
5670:.
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5591:.
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3383:gk
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3003:.
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2820:,
2808:,
2804:,
2592:,
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2394:.
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2139:,
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1130:DC
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3359:V
3353:a
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3201:·
3194:·
3187:·
3180:·
3153:.
2552:×
2548:×
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2347:.
2307:)
2273:C
2269:B
2265:A
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1106:p
1102:R
1093:=
1088:m
1084:g
1072:a
1069:R
1063:p
1060:R
1054:m
1051:g
1045:m
1042:g
1015:×
1007:×
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