Identification and use of commonly used metaware (xxiii)
A long-standing electronic tube
Chang xiaodong
Electronic tubes (electron tube) are commonly known in the port area as “bold”, which is an electronic device that produces current conductives in closed containers such as glass tubes and that effectively controls electronic flow in a vacuum or thin gas through the electric field to complete the current, to detect waves, to signal amplification or oscillation. Because of the almost complete vacuum in the casings of the most commonly used tubes, only a small amount of inert gases or mercury vapours are filled in individual cases, the tubes are divided between vacum tube and gas fill trubes. The frequent electronic tubes are almost entirely vacuum tubes。
As a long-standing electronic device, electronic tubes have contributed significantly to the development of electronic technologies. Later, due to the emergence and rapid development of semiconductor devices, electronic tubes gradually relinquished and withdrew from a growing number of areas. However, electronic tubes are still being used as audio power amplifiers in a number of high-precipitation sound devices, which are particularly popular with and favoured by sound “fever friends”. The live introduction of early electronic tube radios in recent years, as well as the introduction to the production of “coward machines” in amateur conditions, has not only emboldened many old readers, but has also given rise to a growing interest among young radio lovers. Therefore, mastery of the methods of identification and use of general electronic tubes remains essential。
1. How to identify electronic tubes
(1) structure and characteristics
There are many types of electronic tubes and their use varies. However, since they are almost all devices that use electric fields to effectively control free electronic transmission in a vacuum, despite their structural characteristics, their basic components have many similarities, consisting largely of bases, heating lights, electrodes and casings. Among them, electrodes are key building blocks of electro-pipes, usually three electrodes, such as cathodes, screens and fences, which are made of different metals or alloys (e. G. Nickel, molybdenum, tungsten, chromium, copper, iron and its alloys)。
Figure 1 shows the structure of the small tubes that are commonly used. It is known that the cathode is located in the centre of the electronic tube, in the form of sawn teeth or cylinders, and its mission is to heat the electron with light. The screen poles (also known as the anodes or plate poles) are located in the outermost layers of the electrodes, with flats, rectangles, cylinders and ellipses, and their task is to receive electrons from the cathodes and to form the current of the screens. The fence is a cylinder, elliptical or rectangular fence made of very thin wires or metallic nets, located between the cathode and the anode, and its function is to control the number of electrons that are launched from the cathode and eventually reach the screen pole to achieve the minimum enhanced voltage signal function。
The number of layers of different types of electronic tubes varies, and the triodes have only one (i. E., the control fence). The addition of a mesh of electrodes - curtains - to the cascading poles of the tripolar tube constitutes an ordinary quadratic tube with a significantly enhanced magnification capacity that can be used for high frequency circuits. The addition of a grid of electrodes between the poles and the poles of the quadratic tube — the inhibition poles — constitutes a pentapolar tube capable of inhibiting the screen poles with a “second electronic launch” that smooths the beginning of the polarity curve. There is also a commonly used beam-fired tetrapolar tube (also known as a condensed quadratic tube) which has a cathode, control fence, curtain pole, screen and central screen, which is placed between the cathodes and poles and is linked to the cathode, and which allows the electronic flow to be concentrated from the opening of the integrated screen, not only increasing the screen, but also effectively inhibiting the “second electronic launch” of the screen and enhancing its magnification capability. The beaming tetrapolar tubes are almost all power tubes capable of generating large screen currents, with a significantly superior magnification capacity than the ordinary tripolar tubes, integrated above the pentapolar tubes and commonly used. If there is not even a fence inside the electronic tube, it constitutes a diode with only cathodes and screens, current or detection effects。
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Figure 1
The cathode heating of the electrode can be divided into two types of direct heat and side heat (also known as interheated heat), with the cathode of the direct electrode and the heating light “one”, while the cathode and heating of the side tube are close and separate. When the grid of the electro-barrel controls is equally spaced, the screen has a steeper cut-off characteristic along with the electro-voltage of the fence, known as the sharp cut-off tube; when the gap of the ring is trimmed, the screen ends slowly with the voltage of the fence, known as the remote cut-off tube or the "transforming catheter" or "transforming mite"。
The electrode electrodes are installed on insulation bases and are sealed in vacuum tube casings pumped from air. Almost all tube casings use glass casings, but there are also metal casings. It should be noted that, due to manufacturing processes, impurity attachments, and the material itself, there is a trace of residual gas in the electronic tube, and in order to ensure a vacuum in the tube, the finished tube is either placed in the tube or coated with a degas (also referred to as inhalants, degasants). Sterilizers typically use nitrogen-blended distilled aluminum or aluminum. In order to facilitate use and increase consistency, two identical or two different electronic tubes are often assembled in one shell, known as “complex tubes”。
(2) appearance and type
The physical shape of the commonly used electronic tubes is shown in figure 2. Depending on their size, they can be divided into large tubes, small tubes (nutrients, piping or mt tubes) and super-small tubes, the most common of which are shown in figure 2 (a), small tubes and large glass tubes (g), which are shown in figure 2 (a), different shapes, which can be divided into bottled glass tubes (st), barrel tubes (gt, metal glass tubes), spherical tubes, lock tubes, etc., which are the most common, as shown in figure 2 (b); glass tubes, metal tubes, which can be classified in figure 2 (c), which vary in size, and metal tubes, which vary in number of feet, which can be divided into 4, 5, 7, 8, 9, 11, 12, 14, 20, 25 feet, which are shown in figure 2 (d), which are the most common seven feet and nine feet of tubes, which can be divided into two poles, three poles, four poles, five poles, five poles, seven poles, etc., and three tubes, which are the most commonly shown in size, four caving tubes, two tubes, two tubes, two tubes, two tubes, two frequency。
Small electronic tubes are widely used because of a range of advantages, and internationally recommended varieties are widely international interchangeable。
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(a) size-specification
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(b) distinction by shape
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(c) distinction by shell
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(d) distinction by foot
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(e) distinction by electrodes
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(f) distinction by purpose
Figure 2 classification of commonly used electronic tubes
(3) basic parameters
The main parameters of the electrode under general application are: light-wire voltage uf(v), light-wire current if(ma), screen extreme voltage ua(v), screen extreme current ia(ma), fence voltage ug(v), curtain-barrel voltage ug2(v), inhibition grid voltage ug3(v), cathode and inter-light voltage ukf(v), load resistance rl(k), internal resistance ri(k), output power po(w), magnification coefficient μ(no unit), crossconductor s(ma/v)。
The parameters most closely associated with the amplifier's effects in the magnification circuits are crossconductor s, internal resistance ri and magnification coefficient μ, defined and related to each other as follows:
1 cross-guide s(ma/v). Also referred to as "interlining", this refers to the ratio of Δia to Δug, i. E. S=Δia/Δug, in ma/v, when the screen voltage is fixed. Cross-guide s shows the ability of the electro-barrel to control electrical currents on screen. The greater the general triode transconductor value of 0. 5-10 ma/v, the greater the s value, the greater the ability of the grid to control the screen current。
2 within ri (k). This refers to the ratio of Δua to Δia, i. E., r=ua/Δia, in k, of the Δua voltage of the screen to the corresponding Δia voltage voltage of the polar voltage when the grid is fixed and fixed. It shows the ability of the electrode screen to control the current of the screen. The general barrier value of the tripolar tube is approximately 0. 5 to 100 k, and the smaller the internal barrier, the greater the ability to control the extreme current of the screen。
3 magnification factor (m). This refers to the ratio of Δua to Δug, i. E. = Δua/Δug, of the Δcyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyylyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy it shows how much greater the control of electro-barrel voltage over screen currents than the impact of screen voltage on screen currents. The larger the magnification factor of 2. 5 - 100 for the general triode, the higher the magnification quality of the electrode。
The relationship between the crossconductor s, internal resistance ri and magnifier mi is expressed by formula μ=sxr. This formula is known as the internal equation of the electronic tube. If any of the three parameters were known, the remaining one would be available。
(4) model naming
Nationally produced electronic tubes are named into two main categories, the beginning of the number and the beginning of the letter, each of which typically consist of four parts, the format and meaning of which are shown in figure 3。
Named after a model starting with a number, which is used mainly for electronic tubes such as magnification, mail receipt, small currents, harmonization instructions, etc., the format and meaning are shown in figure 3 (a). The first part is a numerical representation of the integer portion of the filament voltage, of which “1” represents the filtration voltage of 1. 2v, “2” represents the filtration voltage of 2. 4v, “5” represents the filtration voltage of 5v, “6” represents the filtration voltage of 6. 3v and “12” represents the filtration voltage of 12. 6v. The second part indicates the structure and category of the tubes by letter, with “a” for “two control grid transformer tubes”, “b” for “bipolar five tubes”, “c” for “tripolar tubes”, “d” for “bipolar tubes”, “e” for “coordination instructional tubes”, “f” for “tripolar five tubes”, “g” for “bipolar tripolar tubes”, “h” for “bipolar tubes”, “j” for “deep to five polar tubes and beaming four polar tubes”, “k” for “tread to five polar tubes and beaming four polar tubes”, “n” for “tripolar tubes”, “p” for “outputing pentapolar tubes and beaming four polar tubes”, “s” for “qane poles”, “z” for “small power flow two polar tubes”. Part iii shows numbers of serial numbers of the same type of tube (designing specifications, performance, etc.). For example, both 6n1 and 6n2 are diodes, but the former have a medium magnification factor and the latter have a high magnification factor. Part iv presents the material and shape of the electronic tube casings with letters, in which “p” represents the ordinary glass casings, “k” represents the metal ceramic tubes, “j” represents the oak tubes, with no letters representing small glass tubes (i. E. Peanut tubes), etc. For example, the 6a2 means a hepta-variant frequency tube with a filamental voltage of 6. 3v, a small glass tube; the 6p1 means an output beam quad tube with a filamentary voltage of 6. 3v, a small glass tube; and the 6p6p means an output beam beam beam tube with a quad tube with a filtration of 6. 3v, a normal glass tube。
(a) start with numbers
(b) letter beginning
Figure 3 naming rules for nationally produced electronic tubes
Named after the letter-based model, which is used mainly for electronic tubes such as launch, high-pressure flow, steady pressure, lock flow, the format and meaning of which are shown in figure 3 (b). Part i indicates the type of electronic tube by letter, with “f” for “launch tube”, “fd for “long wave or short wave launch tube”, “fu” for “super short wave launch tube”, “fc” for “micowave launch tube”, “fl” for “centimetre wave launch tube”, “fm” for “pulse launch tube”, “e” for “vacuum high voltage current diode”, “eq” for “abstract flow binary tube”, “eg” for “mercury gas flow binary tube”, “em” for “vacuum pulse flow diode tube”, “t” for “massive tube”, “wy” for “softure tube”, “zq” for “abstance pipe”. The second part shows numbers of serial numbers for the same type of tube, with the main distinction between specifications, performances, etc., and is generally preceded by the addition of short “-” numbers. Part three is an alphanumeric representation of the shape of the shell, which is the same as part four, which starts with a number. The fourth part is alphabetically described as pipe cooling, with “s” for water cooling and “f” for wind cooling. Part four of the pneumatic piping tube is commonly used to indicate that the molecule indicates the average aberration (i. E. The current value of the whole current) of the allowed screen and the denominator indicates the maximum counterpeak voltage. In some cases, parts iii and iv were omitted. For example, the fu-5 means a dedicated triode for launching; fu-7
