Ламповые цоколи: конструкция, история и применение.

Plug in vacuum tube holder

Tube sockets are electrical sockets into which vacuum tubes (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 stores had vacuum tube testers, and sold replacement tubes. Some Nixie tubes 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 soldered to lugs on the underside of the socket. In the 1950s, printed circuit boards 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 era. In the 1930s, tubes often had the connection to the control grid 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. 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 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 earliest tubes, like the Deforest Spherical Audion 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).

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, 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, 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 (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 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.

In April 1935, the General Electric Company 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 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 connectors; bases from a discarded tubes could be salvaged for this purpose. Octal sockets were used to mount other components, particularly electrolytic capacitor assemblies and electrical relays; 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 amplifiers. Relays were historically manufactured in a vacuum tube form, and industrial grade relays continue to use the octal base for their pinout.

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 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) 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, 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 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, 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 small enough to fit in a handbag or coat pocket. This model had the following tube lineup: 1R5 — pentagrid converter; 1T4 — I. F. amplifier; 1S5 — Detector/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. 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. 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.)

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.

By 1935 new tube technologies were required for the development of radar and telecommunications. UHF 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 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. Nuvistors 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 MR 70, a costly studio tape recorder whose entire electronics section was based on nuvistors.

Common Name Standard Name Other names Base Pins Pin Layout Pin thickness Specification Period Examples European / Pro Electron numeric range Pee Wee B3A US Pee Wee 3p 3 08.7mm triangle with pins 1&3 closest 2.36mm 1937 ZA1004 Mazda subminiature B3G European special all glass miniature 3 (+top) 06.0mm line with 3mm spacing 1mm Mazda 1937 D1, EA50 European 3 pin H3A British 3 pin, Eu 3 (or B4, ignoring pin 4) 3 16mm isosceles triangle, greatest distance between pins 2 & 3 3.2mm 1920s to early 1930s (superseded by Octal and P8) RE4120, 1832 UV4 B4B WD 4 Pin 4 09.8mm rectangle with large pin 2 (usually anode) 2.3mm x3 3.1mm (pin 2) 1914 1920's (superseded by UX4) WD 11 UX4 U4A American 4 pin base with or without bayonet pin 4 11.9mm rectangle with thicker pins 1 & 4. Superseded the UV4 base 3.2mm (pins 2&3) 4.0mm (pins 1&4) A4 10 1920s 1930s (mostly superseded by Octal, but still used for some currently produced directly heated triodes) A P Oscillator (1920), 2A3, 300B, B405, X99, WW313A (1938), 866A B4 A4A British 4 pin, A4, European 4 pin 4 16.25mm kite 3.2mm 1915 to early 1930s (superseded by Octal and P8) B405, BL2, R type UY5 UX5 U5A B5C US 5 contact American Small 5 pin, USS5 5 19mm (3/4") circle, 3x60° between pins 1,2 and 4,5,1, 2x90° between pins 2,3,4 3.? A5 11 1920s UY227, 2E22, 1D4, 49, 807 B5 O5A British 5 pin, European 5 pin, Europa 5 16.25mm kite; B4 with central 5th pin added a B5 socket will accept European 3 pin (H3A) and 4 pin (A4A) tubes 3.2mm 1928 to early 1930s (superseded by Octal and P8) B443 UX6 U6A US 6 pin 6 19mm (3/4") circle, 6x60° 3.2mm x4, 3.9mm (pins 1 & 6) 1930's (superseded by Octal) 1F6, 2A5 B7 M7A British 7 pin 7 23.1mm x 18.2mm oval 3.2mm 1930s (ultimately superseded by Octal) AC3/Pen, TDD4, AL60, 18013 UX7 U7A US 7 pin small 7 19mm (3/4") circle, 3x52°,4x51° 3.2mm x5,3.9mm (pins 1&7) 1930's (superseded by Octal) 2B7, 6A7 SeptarB7A726mm circle2.7mm x6, 4.0mm6C33, 829B, 3C33, 3E29, 832A, 5894, FU 29, GZ67 C Miniature 7 Pin B7G Miniature, Button, Mi 7 7 09.53mm (3/8") circle, 6x45° then 90° between pins 7 & 1 1.016mm IEC 67 I 10a 1939 present 1S4/DL91, 6AQ5, 6X4 90 99, some 100 109, 190 199, 900 999 Transcontinental P8A P Type, Ct8, Philips 8, Side contact 8 8 29.5mm circle of side contact pins, 3x30° (pins 1 4),5x54° Side contact Philips 1930s AL3 1 9 usually Octal K8A IO, International Octal, A08, American octal base, Oc 8 8 17.45mm (11/16") circle, equal 45° spacing, 7.8mm spigot 2.36mm originally: RCA IEC 67 I 5a 1935 present 6CA7/EL34, 6L6/5881, 6SN7, 6V6GT, KT63/KT66/KT77/KT88/KT90, 6550, 7591 3G, 30 39, 300 399 Mazda Octal 8 18.5mm circle, 55,5° between pin 1 and 8, 43,5° between the other pins, 8.7mm spigot 2.36mm Mazda 1938 ? (short lived)ARP12, AR8, SP42, ATP4 or B8B 8 pin Loktal, Lo 8, Locking Octal 8 17.45mm (11/16") circle, equal 45° spacing, 6.7mm spigot 1.3mm Sylvania 1939 1LN5, EF22, ECH71 20 29 and some others Rimlock B8A European 8 pin Miniature base, Ri 8 8 11.5mm (0.453") circle, 45° 1.015mm IEC 67 I 11b 1940s quickly edged out by Noval, etc 6CU7/ECH42,EL41 40 49 Loctal 9pin B9G 9 pin Loctal, Lo 9 9 21.0mm (13/16") circle, equal 40° spacing, spigot connected to can 1.3mm Philips 1938 announced Sept. 1938 and available to Pye; general availability early 1939. EC52 EF50 EF54 EL60 50 60 with some exceptions Noval (Miniature 9 pin) B9A American Small Button, Button 9 pin 9 11.89mm (15/32") circle, 8x36° then 72° spacing between pins 9 & 1 1.016mm IEC 67 I 12aJEDEC E9 1 1948 present (still very popular) 12AX7/ECC83, 6BQ5/EL84 80 89, 180 189, 800 899 Magnoval B9D 9 17.45mm (11/16") circle, 8x36° then 72° spacing between pins 9 & 1 1.27mm IEC 67 I 36aJEDEC E9 23 1960s 1970sdied out when TVs went fully solid state E55L, ED500, PL504 500 599 Novar B9E 9 pin compactron 9 17.45mm (11/16") circle, 9x36° then gap between pins 9 & 1 Note: Novar sockets can be damaged by inserting Magnoval tubes 1.02mm JEDEC E9 65JEDEC E9 89 1959 limited use; mainly TV horiz. output, damper 6JF6, 22JG6A, 7868 Decal B10B or B10C? often incorrectly stated Dekal 10 11.89mm (15/32") circle, 9x34° then 54° gap between pins 10 & 1 1.016mm IEC 67 I 41a JEDEC E10 61 1960s 1970s PFL200, ECC2000, ECH200, PCF201 200 2992000 Decar B10G Dekar 10 11.89mm (15/32") circle as Noval, with additional center pin 1.016mm SylvaniaJEDEC E10 73 Mid Late 1960s 6C9, 17C9Y10AG10A (G8A tubes fit with pins 6 & 10 unused)1028mm circle, 2 groups of 5 pins with two gapsAZ11, EC156 Sub Magnal B11A Magnal, B11 11 17.45mm (11/16") circle as Octal 1.27mm RCA? 1940s to present DuoDecal B12A Duodekal, B12 12 27mm (1.063") circle, 30° angles 2.36mm B12 43 1950s 1970s DG7 31, E1T, MW61 80 Duodecar B12C 12 Pin Compactron, E12 70, E12 74 12 19.1mm (3/4") circle, 11x 27.7° then gap between pins 12 & 1 1.02mm E12 70(T9)E12 74(T12) 1960s 1970s 1BY2, 6BD11, 12BT3 NuvistorE5 655only pins 2, 4, 8 10, 12 used from Twelvar<1mmE5 658393 Nuvistor B12K Twelvar E7 83, E12 64, E12 65 12 11.2mm circular envelope with mixed spacing field of pins <1mm IEC 67 I 17a JEDEC E12 64(5/12) 1959 7586, 6DV4, 6DV8, 13CW4