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Tube sockets are electrical sockets into which
vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as ...
s (electronic valves) can be plugged, holding them in place and providing terminals, which can be soldered into the circuit, for each of the pins. Sockets are designed to allow tubes to be inserted in only one orientation. They were used in most tube electronic equipment to allow easy removal and replacement. When tube equipment was common, retailers such as
drug store A pharmacy (also called "drugstore" in American English or "community pharmacy" or "chemist" in Commonwealth English, or rarely, apothecary) is a retail shop which provides pharmaceutical drugs, among other products. At the pharmacy, a pharmac ...
s had vacuum tube testers, and sold replacement tubes. Some
Nixie tube A Nixie tube ( ), or cold cathode display, is an electronic device used for displaying numerals or other information using glow discharge. The glass tube contains a wire-mesh anode and multiple cathodes, shaped like numerals or other symbo ...
s were also designed to use sockets. Throughout the tube era, as technology developed, sometimes differently in different parts of the world, many tube bases and sockets came into use. Sockets are not universal; different tubes may fit mechanically into the same socket, though they may not work properly and possibly become damaged. Tube sockets were typically mounted in holes on a sheet metal chassis and wires or other components were hand
solder Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...
ed to lugs on the underside of the socket. In the 1950s,
printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich str ...
s were introduced and tube sockets were developed whose contacts could be soldered directly to the printed wiring tracks. Looking at the bottom of a socket, or, equivalently, a tube from its bottom, the pins were numbered clockwise, starting at an index notch or gap, a convention that has persisted into the
integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
era. In the 1930s, tubes often had the connection to the
control grid The control grid is an electrode used in amplifying thermionic valves (vacuum tubes) such as the triode, tetrode and pentode, used to control the flow of electrons from the cathode to the anode (plate) electrode. The control grid usually consist ...
brought out through a metal top cap on the top of the tube. This was connected by using a clip with an attached wire lead. An example would be the 6A7
pentagrid converter The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an ...
. Later, some tubes, particularly those used as radio frequency (RF) power amplifiers or horizontal deflection amplifiers in TV sets, such as the 6DQ6, had the plate or
anode An anode is an electrode of a polarized electrical device through which conventional current enters the device. This contrasts with a cathode, an electrode of the device through which conventional current leaves the device. A common mnemonic is ...
lead protrude through the envelope. In both cases this allowed the tube's output circuitry to be isolated from the input (grid) circuit more effectively. In the case of the tubes with the plate brought out to a cap, this also allowed the plate to run at higher voltages (over 26,000 volts in the case of rectifiers for color television, such as the 3A3, as well as high-voltage regulator tubes.) A few unusual tubes had caps for both grid and plate; the caps were symmetrically placed, with divergent axes.


The first tubes

The earliest tubes, like the '' Deforest Spherical
Audion The Audion was an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest in 1906.De Forest patented a number of variations of his detector tubes starting in 1906. The patent that most clearly covers ...
'' from c. 1911, used the typical light bulb Edison socket for the heater, and flying leads for the other elements. Other tubes directly used flying leads for all of their contacts, like the ''Cunningham AudioTron'' from 1915, or the ''Deforest Oscillion''. Type C6A xenon thyratrons, used in servos for the U.S. Navy Stable Element Mark 6, had a mogul screw base and L-shaped stiff wires at the top for grid and anode connections. Mating connectors were machined pairs of brass blocks with clamping screws, attached to flying leads (free hanging).


Early bases

When tubes became more widespread, and new electrodes were added, more connections were required. Specially designed bases were created to account for this need. However, as the world was suffering from
World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
, and the new electronics technology was just emerging, designs were far from being standardized. Usually, each company had their own tubes and sockets, which were not interchangeable with tubes from other companies. By the early 1920s, this situation was finally changing, and several standard bases were created. They consisted of a base (ceramic, metal,
bakelite Polyoxybenzylmethylenglycolanhydride, better known as Bakelite ( ), is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. The first plastic made from synthetic components, it was developed ...
, etc.) with a number of prongs ranging from three to seven, with either a non-regular distribution or with one or two of the prongs of bigger diameter than the other, so that the tube could only be inserted in a certain position. Sometimes they relied on a bayonet on the side of the base. Examples of these are the very common USA bases UX4, UV4, UY5 and UX6, and the European B5, B6, B7, B8, C7, G8A, etc. Tubes in the USA typically had from four to seven pins in a circular array, with adjacent pairs of larger pins for heater connections. Before
alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...
(AC) line/mains-powered radios were developed, some four-pin tubes (in particular, the very common UX-201A ('01A)) had a bayonet pin on the side of a cylindrical base. The socket used that pin for retaining the tube; insertion finished with a slight clockwise turn. Leaf springs, essentially all in the same plane, pressed upward on the bottoms of the pins, also keeping the bayonet pin engaged. The first hot-cathode CRT, the
Western Electric The Western Electric Company was an American electrical engineering and manufacturing company officially founded in 1869. A wholly owned subsidiary of American Telephone & Telegraph for most of its lifespan, it served as the primary equipment ma ...
224-B, had a standard four-pin bayonet base, and the bayonet pin was a live connection. (Five effective pins: It was an electrostatic-deflection gas-focused type, with a diode gun and single-ended deflection. The anode and the other two plates were common.) An early exception to these types of bases is the Peanut 215, which instead of using prongs had a tiny bayonet base with four drop-like contacts. Another exception is the European Side Contact series commonly known as P, which instead of using a prong, relied on side contacts at 90 degrees from the tube axis with four to twelve contacts.


Octal

In April 1935, the
General Electric Company The General Electric Company (GEC) was a major British industrial conglomerate involved in consumer and defence electronics, communications, and engineering. The company was founded in 1886, was Britain's largest private employer with over 250 ...
introduced a new eight-pin tube base with their new metal envelope tubes. The new base became known as the ''octal base''. The octal base provided one more conductor with a smaller overall size of the base than the previous line of U. S. tube bases which had provided a maximum of seven conductors. Octal bases, as defined in IEC 60067, diagram IEC 67-I-5a, have a 45-degree angle between pins, which form a diameter circle around a diameter keyed post (sometimes called a ''spigot'') in the center. Octal sockets were designed to accept octal tubes, the rib in the keyed post fitting an indexing slot in the socket so the tube could only be inserted in one orientation. When used on metal tubes, pin 1 was always reserved for a connection to the metal shell, which was usually grounded for shielding purposes. This reservation prevented tubes such as the 6SL7/6SN7 dual triodes from being issued with metal envelopes, as such valves need three connections (cathode, grid, anode) for each triode (making six total) plus two connections for the paralleled heaters. The octal base soon caught on for glass tubes, where the large central post could also house and protect the " evacuation tip" of the glass tube. The eight available pins allowed more complex tubes than before, such as dual triodes, to be constructed. The glass envelope of an octal base tube was cemented into a
bakelite Polyoxybenzylmethylenglycolanhydride, better known as Bakelite ( ), is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. The first plastic made from synthetic components, it was developed ...
or plastic base with a hollow post in the center, surrounded by eight metal pins. The wire leads from the tube were soldered into the pins, and the evacuation tip was protected inside the post. Matching plugs were also manufactured that let tube sockets be used as eight-pin
electrical connector Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection betwee ...
s; bases from a discarded tubes could be salvaged for this purpose. Octal sockets were used to mount other components, particularly
electrolytic capacitor An electrolytic capacitor is a polarized capacitor whose anode or positive plate is made of a metal that forms an insulating oxide layer through anodization. This oxide layer acts as the dielectric of the capacitor. A solid, liquid, or gel e ...
assemblies and electrical
relay A relay Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts An automotive-style miniature relay with the dust cover taken off A relay is an electrically operated switch ...
s; octal-mount relays are still common. Most octal tubes following the widespread European designation system have penultimate digit "3" as in ECC34 (full details in the Mullard–Philips tube designation article). There is a different, totally obsolete, pre-world-war-II German octal type. Octal and miniature tubes are still in use in tube-type audio hi-fi and
guitar amplifier A guitar amplifier (or amp) is an electronic device or system that strengthens the electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which ar ...
s. Relays were historically manufactured in a vacuum tube form, and industrial-grade relays continue to use the octal base for their pinout. File:6P3S.jpg, An octal base tube, Russian 6Π3C, similar to the
6L6 6L6 is the designator for a beam power tube introduced by Radio Corporation of America in April 1936 and marketed for application as a power amplifier for audio frequencies.J. F. Dreyer Jr."The Beam Power Output Tube" New York: McGraw-Hill, ''Ele ...
. File:6SN7 octal base.jpg, Octal base of a
6SN7 6SN7 is a dual triode vacuum tube with an eight-pin octal base. It provides a medium gain (20 dB). The 6SN7 is basically two 6J5 triodes in one envelope. History Originally released in 1939 it was officially registered in 1941 by RCA and Syl ...
File:Vacuum tube octal socket.jpg, An octal socket


Loctal

A variant of the octal base, the B8G loctal base or ''lock-in'' base (sometimes spelled "loktal" — trademarked by Sylvania), was developed by Sylvania for ruggedized applications such as automobile radios. Along with B8B (a British designation out of date by 1958), these eight-pin locking bases are almost identical and the names usually taken as interchangeable (although there are some minor differences in specifications, such as spigot material and spigot taper, etc.). The pin geometry was the same as for octal, but the pins were thinner (although they will fit into a standard octal socket, they wobble and do not make good contact), the base shell was made of aluminium, and the center hole had an electrical contact that also mechanically locked (hence "loctal") the tube in place. Loctal tubes were only used widely by a few equipment manufacturers, most notably
Philco Philco (an acronym for Philadelphia Battery Company) is an American electronics industry, electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchased ...
, which used the tubes in many table radios. Loctal tubes have a small indexing mark on the side of the base skirt; they do not release easily from their sockets unless pushed from that side. Because the pins are actually the Fernico or
Cunife Cunife is an alloy of copper (Cu), nickel (Ni), iron (Fe), and in some cases cobalt (Co). The alloy has the same linear coefficient of expansion as certain types of glass, and thus makes an ideal material for the lead out wires in light bulbs and ...
lead-out wires from the tube, they are prone to intermittent connections caused by the build-up of electrolytic corrosion products due to the pin being of a different metallic composition to the socket contact. The loctal tube's structure was supported directly by the connecting pins passing through the glass "button" base. Octal tube structures were supported on a glass "pinch", formed by heating the bottom of the envelope to fusing temperature, then squeezing the pinch closed. Sealing the pinch embedded the connecting wires in the pinch's glass and gave a vacuum-tight seal. The connecting wires then passed through the hollow base pins, where they were soldered to make permanent connections. Loctal tubes had shorter connecting lengths between the socket pins and the internal elements than did their octal counterparts. This allowed them to operate at higher frequencies than octal tubes. The advent of miniature "all-glass" seven- and nine-pin tubes overtook both octals and loctals, so the loctal's higher-frequency potential was never fully exploited. Loctal tube type numbers in the USA typically begin with "7" (for 6.3-volt types) or "14" for 12.6-volt types. This was fudged by specifying the heater voltage as ''nominally'' 7 or 14 volts so that the tube nomenclature fitted. Battery types (mostly 1.4-volt) are coded "1Lxn", where ''x'' is a letter and "n" a number, such as "1LA4". Russian loctals ''end'' in L, e.g. 6J1L. European designations are ambiguous; all B8G loctals have numbers either in the range: * 20–29, (such as EBL21, ECH21, EF22) except for early tubes in the series: DAC21, DBC21, DCH21, DF21, DF22, DL21, DLL21, DM21 which have either B9G or octal bases, the change to Sylvania's locktal standard coming in 1942 * or 50–59 (special bases, including the European 9-pin lock-in base), but other types are in the same range (e.g. while EF51 is B8G loctal, the EF55 is 9-pin loctal, B9G, and the EL51 has a side-contact P8A base).


Other loctals

* Nine-pin loctal bases, B9G, include the 1938 Philips
EF50 In the field of electronics, the EF50 is an early all-glass wideband remote cutoff pentode designed in 1938 by Philips. It was a landmark in the development of vacuum tube technology, departing from construction ideas of the time essentially uncha ...
, EL60 and some type numbers in the European 20–29 and 50–59 range; * There is a different "loctal Lorenz" in the Mullard–Philips tube designation .


Miniature tubes

Efforts to introduce small tubes into the marketplace date from the 1920s, when experimenters and hobbyists made radios with so-called peanut tubes like the Peanut 215 mentioned above. Because of the primitive manufacturing techniques of the time, these tubes were too unreliable for commercial use. RCA announced new miniature tubes in ''Electronics'' magazine, which proved reliable. The first ones, such as the 6J6 ECC91
VHF Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF ...
dual triode, were introduced in 1939. The bases commonly referred to as "miniature" are the seven-pin B7G type, and the slightly later nine-pin B9A (Noval). The pins are arranged evenly in a circle of eight or ten evenly spaced positions, with one pin omitted; this allows the tube to be inserted in only one orientation. Keying by omitting a pin is also used in 8- (subminiature), 10-, and 12-pin (
Compactron Compactrons are a type of thermionic valve, or vacuum tube, which contain multiple electrode structures packed into a single enclosure. They were designed to compete with early transistor electronics and were used in televisions, radios, and simil ...
) tubes (a variant 10-pin form, "Noval+1", is basically a nine-pin socket with an added center contact). As with loctal tubes, the pins of miniature tube are stiff wires protruding through the bottom of the glass envelope which plug directly into the socket. However, unlike all their predecessors, miniature tubes are not fitted with separate bases; the base is an integral part of the glass envelope. The pinched-off air evacuation nub is at the top of the tube, giving it its distinctive appearance. More than one functional section can be included in a single envelope; a dual triode configuration is particularly common. Seven- and nine-pin tubes were common, though miniature tubes with more pins, such as the Compactron series, were later introduced, and could fit up to three amplifying elements. Some miniature tube sockets had a skirt that mated with a cylindrical metal electrostatic shield that surrounded the tube, fitted with a spring to hold the tube in place if the equipment was subject to vibration. Sometimes the shield was also fitted with thermal contacts to transfer heat from the glass envelope to the shield and act as a
heat sink A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is dissipated away from the device, ...
, which was considered to improve tube life in higher power applications. Electrolytic effects from the differing metal alloys used for the miniature tube pins (usually
Cunife Cunife is an alloy of copper (Cu), nickel (Ni), iron (Fe), and in some cases cobalt (Co). The alloy has the same linear coefficient of expansion as certain types of glass, and thus makes an ideal material for the lead out wires in light bulbs and ...
or Fernico) and the tube base could cause intermittent contact due to local corrosion, especially in relatively low current tubes, such as were used in battery-operated radio sets. Malfunctioning equipment with miniature tubes can sometimes be brought back to life by removing and reinserting the tubes, disturbing the insulating layer of corrosion. Miniature tubes were widely manufactured for military use during World War II,The National Valve Museum: 6J6
/ref> and also used in consumer equipment. The Sonora Radio and Television Corporation produced the first radio using these miniature tubes, the "Candid", in April 1940. In June 1940 RCA released its battery-operated Model BP-10, the first
superheterodyne receiver A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original car ...
small enough to fit in a handbag or coat pocket. This model had the following tube lineup: 1R5 —
pentagrid converter The pentagrid converter is a type of radio receiving valve (vacuum tube) with five grids used as the frequency mixer stage of a superheterodyne radio receiver. The pentagrid was part of a line of development of valves that were able to take an ...
; 1T4 — I.F. amplifier; 1S5 —
Detector A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...
/AVC/AF Amplifier; 1S4 — Audio Output. The BP-10 proved so popular that Zenith, Motorola, Emerson, and other radio manufacturers produced similar pocket radios based on RCA's miniature tubes. Several of these pocket radios were introduced in 1941 and sold until the suspension of radio production in April 1942 for the duration of World War II. After the war miniature tubes continued to be manufactured for civilian use, regardless of any technical advantage, as they were cheaper than octals and loctals.


Miniature seven-pin base

The B7G (or "small-button" or "heptal") seven-pin miniature tubes are smaller than Noval, with seven pins arranged at 45-degree spacing in a 9.53 mm (3/8th inch) diameter arc, the "missing" pin position being used to position the tube in its socket (unlike octal, loctal and rimlock sockets). Examples include the 6AQ5/EL90 and 6BE6/EK90. European tubes of this type have numbers 90-99, 100-109, 190-199, 900-999. A few in the 100-109 series have unusual, non-B7G bases, ''e.g.'', Wehrmacht base.


Noval base

The nine-pin miniature Noval B9A base, sometimes called button 9-pin, B9-1, offered a useful reduction in physical size compared to previous common types, such as octal (especially important in TV receivers where space was limited), while also providing a sufficient number of connections (unlike B7G) to allow effectively unrestricted access to all the electrodes, even of relatively complex tubes such as double triodes and triode-hexodes. It could also provide multiple connections to an electrode of a simpler device where useful, as in the four connections to the grid of a conventional grounded-grid UHF triode, ''e.g.'', 6AM4, to minimise the deleterious effects of lead inductance on the high-frequency performance. This base type was used by many of the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
and most of the European tubes, ''e.g.'',
12AX7 12AX7 (also known as ECC83) is a miniature dual- triode 6AV6 vacuum tube with high voltage gain. Developed around 1946 by RCA engineers in Camden, New Jersey, under developmental number A-4522, it was released for public sale under the 12AX7 ide ...
-ECC83, EF86 and EL84, produced commercially towards the end of the era before
transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
s largely displaced their use. The IEC 67-I-12a specification calls for a 36-degree angle between the nine pins of 1.016 mm thickness, in an arc of diameter 11.89 mm. European tubes of this type have numbers 80-89, 180-189, 280-289, 800-899, 8000-8999.


Duodecar base

The Duodecar B12C base (IEC 67-I-17a) has 12 pins in a 19.1 mm diameter circle and dates from 1961. It was also called the
Compactron Compactrons are a type of thermionic valve, or vacuum tube, which contain multiple electrode structures packed into a single enclosure. They were designed to compete with early transistor electronics and were used in televisions, radios, and simil ...
T-9 construction/E12-70 base It is generally similar in form to a Noval socket, but larger. In the center is a clearance hole for a tube evacuation pip, which is typically on the bottom of a Compactron tube. (It should not be confused with the similar-sounding but differently sized Duodecal B12A base.)


Rimlock base

The Rimlock (B8A) base is an eight-pin design with a pin circle diameter close to Noval, and uses a nub on the side of the envelope to engage with a guide and retaining spring in the socket wall. This provides pin registration (since the pins are equi-spaced) and also a fair degree of retention. Early tubes with this base type typically had a metal skirt around the lower ~15mm of the envelope to match the socket wall, and this offered a degree of built-in screening, but these were fairly soon replaced by "skirtless" versions, which had a characteristic widening in the glass to compensate physically for the absence of the skirt. In the European naming scheme, rimlock tubes are numbered in the ranges 40-49, 110-119 (with exceptions), and 400-499, ''e.g.'', EF40. Although virtually unknown elsewhere, this was a very common base type in European radios of the late 1940s through the 1950s, but was eventually displaced by the ubiquitous B7G and Noval (B9A) base types.


UHF tubes

By 1935 new tube technologies were required for the development of radar and telecommunications.
UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...
requirements severely limited the existing tubes, so radical ideas were implemented which affected how these tubes connected to the host system. Two new bases appeared, the
acorn tube The 955 is typical of the acorn designs, named for the glass cap holding the terminals with the main part of the tube extending from it. An acorn tube, or acorn valve, refers to any member of a family of VHF/ UHF vacuum tubes starting just befor ...
and the lighthouse tube, both solving the same problems but with different approaches. Thompson, G.M. Rose, Saltzberg and Burnside from RCA created the acorn tube by using far smaller electrodes, with radial short connections. A different approach was taken by the designers of the lighthouse tube, such as the octal-base 2C43, which relied on using concentric cylindrical metal contacts in connections that minimized inductance, thus allowing a much higher frequency.
Nuvistor The nuvistor is a type of vacuum tube announced by RCA in 1959. Nuvistors were made to compete with the then-new bipolar junction transistors, and were much smaller than conventional tubes of the day, almost approaching the compactness of e ...
s were very small, reducing stray capacitances and lead inductances. The base and socket were so compact that they were widely used in UHF TV tuners. They could also be used in small-signal applications at lower frequencies, as in the
Ampex Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name AMPEX is a portmanteau, created by its founder, which stands for Alexander M. Poniatoff Excellence.AbramsoThe History ...
MR-70, a costly studio
tape recorder An audio tape recorder, also known as a tape deck, tape player or tape machine or simply a tape recorder, is a sound recording and reproduction device that records and plays back sounds usually using magnetic tape for storage. In its present ...
whose entire electronics section was based on nuvistors.


Other socket styles

There are many other socket types, of which a few are: * Decal B10B base (IEC 67-I-41a) 10 pins with 1.02 mm diameter in an 11.89 mm diameter circle, e.g. PFL200 * Decar B10G base (IEC E10-73) A 10th pin added to the center of a standard 9-pin miniature base, e.g. 6C9 * Magnoval B9D base (IEC 67-I-36a) 9 pins with 1.27 mm diameter in a 17.45 mm pin circle diameter arc, e.g. EL503, EL509, PD500, etc. - not to be confused with... * Novar B9E base, 9 pins with 1.02 mm diameter in a 17.45 mm pin circle diameter arc, one of several Compactron types, which looks similar to Magnoval (but a Novar tube in a Magnoval socket will not make good pin contact, and a Magnoval tube in a Novar socket may damage the socket). * Sub-Magnal B11A base (American), 11-pins. Also used as industrial relay socket and HV power supplies. Amphenol / WirePro (WPI) / Eaton 78-series, Socket (female) part number: 78-S-11. Matching Plug (male) is part number: 86-CP-11 * Neo Eightar base (IEC 67-I-31a) 8 pins in a 15.24 mm diameter circle * 5-pin sub-miniature wire-ended B5A base (no socket used; e.g. EA76) A remarkably wide variety of tube and similar sockets is listed and described, with some informal application notes, at a commercial site, Pacific T.V., including nuvistor, eight-pin subminiature, vidicon, reflex klystron, nine-pin octal-like, 10-pin miniature (two types), 11-pin sub-magnal, diheptal 14-pin, and many display tubes such as Nixies and vacuum fluorescent types (and even more). As well, each socket has a link to a clear, high-quality picture. Some subminiature tubes with flexible wire leads all exiting in the same plane were connected by subminiature inline sockets. Some low-power
reflex klystron A klystron is a specialized linear-beam vacuum tube, invented in 1937 by American electrical engineers Russell and Sigurd Varian,Pond, Norman H. "The Tube Guys". Russ Cochran, 2008 p.31-40 which is used as an amplifier for high radio freque ...
s such as the 2K25 and 2K45 had small-diameter rigid coaxial outputs parallel to octal base pins. To accommodate the coax, one contact was replaced by a clearance hole. Vacuum tubes for high-power applications often required custom socket designs. A jumbo four-prong socket was used for various industrial tubes. A specialized seven-pin socket (Septar or B7A), with all pins in a circle with one pin wider than the others, was used for transmitting tubes. Subminiature tubes with long wire leads, introduced in the 1950s, were often soldered directly to printed circuit boards. Sockets were made for early
transistor upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch ...
s, but quickly fell out of favor as transistor reliability became established. This also happened with early integrated circuits; IC sockets later became used only for devices that may need to be upgraded.


Summary of base details

8 Pin Tube Sockets (Rimlock B8A)
/ref> 4 Pin Tube Sockets (UV4 UX4 U4J)
/ref> 7 Pin Tube Sockets Miniature (B7G)
/ref>


References


See also

*
Nuvistor The nuvistor is a type of vacuum tube announced by RCA in 1959. Nuvistors were made to compete with the then-new bipolar junction transistors, and were much smaller than conventional tubes of the day, almost approaching the compactness of e ...
*
Compactron Compactrons are a type of thermionic valve, or vacuum tube, which contain multiple electrode structures packed into a single enclosure. They were designed to compete with early transistor electronics and were used in televisions, radios, and simil ...
* Amphenol *
List of vacuum tubes This is a list of vacuum tubes or ''thermionic valves'', and low-pressure gas-filled tubes, or ''discharge tubes''. Before the advent of semiconductor devices, thousands of tube types were used in consumer electronics. Many industrial, military ...
{{DEFAULTSORT:Tube Socket Vacuum tubes