Vacuum tube - Knowledge

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

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

3302:

When a cathode is heated and reaches an operating temperature around 1050° Kelvin (780 °C), 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

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:. 5647:. 5607:^ 5591:. 5581:10 5579:. 5575:. 5549:. 5539:. 5531:. 5521:. 5511:18 5509:. 5505:. 5482:. 5472:. 5435:. 5383:. 5262:. 5258:. 5213:^ 5058:. 4995:. 4950:. 4942:. 4869:^ 4849:^ 4774:. 4720:^ 4706:. 4624:, 4607:, 4480:. 4470:. 4380:. 4301:. 4279:. 4267:. 4217:. 4192:. 4157:. 3975:, 3950:. 3938:. 3909:^ 3856:. 3825:. 3796:, 3778:11 3776:. 3772:. 3710:^ 3700:. 3628:. 3583:. 3383:gk 3311:. 3014:, 3003:. 2910:A 2820:, 2808:, 2804:, 2592:, 2567:RF 2394:. 2335:. 2331:" 2267:, 2237:. 2139:, 1580:× 1464:A 1438:. 1406:. 1165:. 1130:DC 999:TM 731:. 690:, 686:, 642:, 638:, 430:; 406:, 402:, 349:, 345:, 326:, 229:. 201:, 197:, 193:, 152:DC 56:, 52:, 48:A 7150:e 7143:t 7136:v 6734:) 6730:( 6100:e 6093:t 6086:v 6042:— 5951:. 5880:. 5858:. 5777:. 5746:. 5721:. 5698:. 5686:: 5678:: 5601:. 5595:: 5587:: 5557:. 5525:: 5517:: 5490:. 5468:: 5449:. 5387:. 5368:. 5274:. 4966:. 4926:. 4893:. 4790:. 4760:. 4746:. 4714:. 4702:: 4487:g 4444:. 4417:. 4392:. 4287:. 4275:: 4269:6 4228:. 4202:. 4190:7 4169:. 4111:. 4019:. 4005:. 3958:. 3946:: 3940:6 3888:. 3886:1 3864:. 3784:: 3757:. 3732:. 3661:. 3639:. 3614:. 3380:V 3371:a 3368:V 3362:g 3359:V 3353:a 3350:I 3226:) 3220:( 3215:) 3211:( 3201:· 3194:· 3187:· 3180:· 3153:. 2552:× 2548:× 2544:× 2347:. 2307:) 2273:C 2269:B 2265:A 1625:" 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:× 821:( 410:) 398:( 363:/ 353:) 158:( 31:.

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

Index