The 2N series

The 2N series, created by RETMA, the Radio Electronics & Television Manufacturers Association which in 1957 became the EIA (Electronic Industries Association), was the first series of transistors that contained devices from many vendors using a common numbering system. It was used for a good number of years and contains thousands of types. Although each type number was assigned to one manufacturer, many types were 'second-sourced' by one or more vendors. The 2N21 is the lowest-numbered device in the series: the range 2N1 to 2N20 was not used, although I have one data book that mentions 2N18 and 2N19 by Fivre, an Italian manufacturer that I have never encountered. The classic source for data on early members of this series is the General Electric "Transistor Manual", which was issued annually from 1956, the first edition already having devices up to 2N293. However, GE exclude some devices from certain manufacturers, notably Western Electric, Transitron, National Union and Westinghouse.

This page shows 2N types up to about 2N120, which is an approximate limit of interesting collectable types except for a few higher-numbered ones that are special in some way. The page is graphically intensive and may take some time to load on a slow Internet connection. All types shown are germanium devices unless otherwise noted.

I do not possess all the transistors below, in fact I am seeking many of them. I am indebted to Terry Hoskings, Bob McGarrah and Kail Secrest for a number of the images. It is noted in the text where I am seeking examples of any particular type: if you have some for sale or exchange, please .

The 2N21 from Western Electric is the lowest-numbered device in the series but not the oldest type, it dates from 1955, two years later than several other 2N types. Despite using single-ended packaging, it is a N-type point-contact transistor for use as an AF amplifier.	The 2N21A is a later version of the 2N21 in improved packaging.	The N-type point-contact transistor 2N22 uses the Western Electric "outline number 1" cartridge case. This case plugs into a small socket, and was used by many point-contact types from Bell/WeCo and other manufacturers. The transistor was used as a low-power switch.
The Western Electric N-type point-contact transistor 2N23 uses the "outline number 2" bead case. This case is a plastic semidisk encapsulating the germanium die, which is fixed to the metal strip forming the base connection. The two thin wires are the emitter and collector and connect to the internal point contacts. The transistor was used as a low-power switch.	The 2N24 N-type point-contact transistor uses the Western Electric "outline number 1" cartridge case. It was used as a low-power amplifier oscillator. See Jack Ward's site for more details on this device.	The 2N25 N-type point-contact transistor also uses the Western Electric "outline number 1" cartridge case. It was used as a low-power AF amplifier.
The Western Electric 2N26 is the only 2N type other than 2N23 to use the "outline number 2" bead case. The transistor was used as a low-power switch.	The 2N27 is the first in a trio of Western Electric (and possibly also CBS) grown-junction transistors, and in common with nearly all grown-junction types they have NPN polarity. Some examples come in individual cartons as shown and can be identified by the coloured paint dots using the standard 'resistor code'': red is two and purple is seven. Other examples are printed "2N27". It was used as a low-power AF amplifier. See Jack Ward's site for more details on this trio of transistors.	The 2N28 is the second in this NPN grown-junction trio. Again some examples have paint dots and some have the type number printed on them, as in this example. It was used as a low-power AF amplifier.
The 2N29 is the third in the trio. The example shown is dated August 1956 and uses a more sophisticated package than the crudely soldered 2N27 and 2N28 shown above. However, there is no suffix 'A' as was done for the 2N21.	The 2N30 is listed in the GE Transistor Manual, which states that it is obsolete, and is the "old G11". This is a GE point-contact transistor in a unique small cartridge package, which is shown above. I am seeking examples of this device.	The 2N31 is listed in the GE Transistor Manual first edition, which states that it is obsolete, and is the "old G11A". This is an improved version of the GE G11 point-contact transistor in a unique small cartridge package as shown above. I am seeking examples of this device.
The 2N32 is an RCA point-contact transistor in a single-ended package that has all leads emerging from the same end. The leads were anchored in a small glass block, allowing the transistor to be constructed above it, and then the whole upper part was sealed in a white epoxy block. Two different shapes of this transistor exist, one flatter than the other and with the glass anchor block visible. The transistor was used as a low-power switch. I am seeking examples of this device made by Sylvania, and also examples with an 'A' suffix.	The 2N33 is another RCA point-contact transistor in the same two package shapes as the 2N32. The transistor was used as an RF mixer or oscillator. I am seeking examples of this device made by any other manufacturer. I do possess some mysterious unbranded 2N33A devices in a more modern encapsulation. See Jack Ward's site for more details on this device.	The 2N34 is a PNP junction transistor for use as a low-power AF amplifier. It was the first in the series to be made by many manufacturers including RCA, Sylvania, Transitron, and ETCo (Electronic Transistors Corporation) .
The 2N35, assigned to Sylvania, was also made by other manufacturers: RCA, General Electric, General Transistor, and ETCo. It is a low-power NPN AF type intended for the hobbyist market. See Jack Ward's site for more details on this device. NB composite image, transistor and box are not to scale.	The CBS type 2N36 was also made by Transitron, and possibly by ETCo. It is a PNP high-gain type. The image shows a rare early form in an elongated metal can. It is more usual to find examples in a cylindrical can with a white plastic sleeve, as per the 2N37 and 2N38 which follow. I am seeking examples of this device.	The CBS type 2N37 was also made by Transitron, and possibly by ETCo. It is a PNP medium-gain type. I am seeking examples of this device.
The CBS types 2N38 and 2N38A were also made by Transitron, General Transistor and possibly by ETCo. They are PNP general-purpose AF types. I am seeking examples of these devices.	The PNP types 2N39 and 2N40 PNP-fused transistors were amongst the very few made by National Union Electric, as well as General Transistor. They are designed for general purpose AF amplifier applications.I am seeking examples of these devices.	The RCA type 2N41 is a PNP AF general-purpose type. I am seeking examples of this device.
The type 2N42 PNP-fused transistor was one of the very few made by National Union Electric, as well as General Transistor. It is designed for general purpose AF amplifier applications. I am seeking examples of this device.	The General Electric types 2N43 and 2N43A are alloy-junction PNP units intended for high-gain, low to medium power AF applications. They were also made by several other manufacturers. The package that this and a number of other GE types use is known as the "lady top hat". Some versions have an evacuation port on top, as shown here, others do not. The A suffix denotes the military specification version, with tightly controlled parameters. See Jack Ward's site for more details on this device and the 2N44 and 2N45.	The General Electric type 2N44 is an alloy-junction PNP unit intended for medium-gain, low to medium power AF applications. It was also made by several other manufacturers. The gold-plated one on the left appears to bear the branding "WT" - I'm not sure who this is, please contact me if you know.
The General Electric type 2N45 is an alloy-junction PNP unit intended for medium-gain, low to medium power AF applications. It was also made by several other manufacturers.	The RCA type 2N46 is another PNP type designed for general purpose AF amplifier applications. I am seeking examples of this device.	The Philco types 2N47, 2N48 and 2N49 use their "cigar tube" case. They are alloy-junction high-gain low-noise PNP devices for use in hearing aids. I am seeking examples of these devices.
The Clevite types 2N50, 2N51, 2N52 and 2N53 are N-type point-contact transistors used as oscillators and switches. I am seeking examples of these devices.	The Westinghouse PNP-fused 2N54, 2N55 and 2N56 are a gain-selected trio of low-power AF types. I am seeking examples of these devices.	The Honeywell 2N57 was one of the first true power transistors available commercially. It has a power dissipation of 20 Watts and uses a unique case style. Early examples have a "bell shaped" case as shown and are unbranded. Later ones have a cylindrical case printed "HONEYWELL".
The Westinghouse PNP types 2N58 to 2N61 are designed for general purpose AF amplifier applications. . I am seeking examples of these devices.	The Philco 2N62 is another general purpose AF amplifier type in the typical Philco "cigar tube" case.I am seeking examples of this device.	The 2N63, 2N64 and 2N65 are a trio of gain-banded PNP AF types originated by Raytheon, the gain increasing from 2N63 through to 2N65. These were also made by other manufacturers, notably Tung-Sol in the "baby blue" case shown.
The Western Electric 2N66 is a high-power type for high-current switching and RF amplification.	The Western Electric 2N67 is a point-contact high-speed switching transistor, despite its modern packaging. The image shows an old hand-soldered example and a later one - unlike the 2N21 this was not given an 'A' suffix.	The Sylvania 2N68 is an early PNP-alloyed high-current low-voltage type with a large octagonal finned heatsink. See Jack Ward's site for more details on this device.
The 2N69 is a very obscure type, manufactured by RCA but sometimes ascribed to other vendors in early data books. I am seeking examples of this device.	The part number 2N70 seems to have never been used, although it may be assigned to a manufacturer. If you know anything about it please contact me. I am seeking examples of this device.	The Westinghouse 2N71 is a PNP AF power amplifier type. I am seeking examples of this device.
The RCA 2N72 is an extremely rare point-contact transistor that was only produced in limited quantity under a military "proof of manufacturing" contract. See Jack Ward's site for more details on this device.	The Westinghouse PNP types 2N73 to 2N75 are general-purpose low-frequency switches. I am seeking examples of these devices.	The 2N76 was made by GE, Transitron, and possibly the French company Thomson-Houston. It is a fused-junction PNP AF type with intermediate gain.
The RCA 2N77 is a PNP alloy-junction type for low-power AF applications "where extreme stability is paramount".	The GE 2N78 was a successful NPN type using a new 'rate-grown' junction technology, and was designed for RF and IF amplification in broadcast receivers. See Jack Ward's site for more details on this device.	The RCA 2N79 is a PNP general purpose AF amplifier type.
The CBS 2N80 and 2N82 are general purpose low-power PNP AF types. I am seeking examples of these devices.	The GE 2N81 is a fused-junction PNP unit particularly recommended for high-gain medium-power applications. I am seeking examples of this device.	The Transitron 2N83 and 2N84 are medium-power PNP AF amplifier types. There are 'A' suffix versions of both. I am seeking examples of these devices.
The Transitron 2N85 (shown), 2N86 and 2N87 are PNP medium-power AF amplifier types designed for linear operation over a wide collector current range. They use a TO-22 can with a bar fixed across the back for heat dissipation.	The Transitron 2N88 is a PNP low-power AF amplifier type in an unusual small-diameter cylindrical can.	The Transitron 2N89 and 2N90 are PNP low-power AF amplifier types in the same can as the 2N88. I am seeking examples of these devices.
The Transitron 2N91 is a PNP switching transistor designed for use in the range of 100mA collector current.	The Transitron 2N92 is a PNP switching transistor designed for use in the range of 5mA collector current. I am seeking examples of this device.	The 2N93 is a low-power PNP AF/IF/switching type from Radio Receptor which was "carefully selected for reliable performance in airborne communications equipment".
The 2N94 was made by Sylvania for use as an IF amplifier or high-speed switch. Older examples use a large proprietary encapsulation, later ones a more standard TO-22 like can. This device had an 'A' suffix version.	The Sylvania 2N95 is an NPN-alloyed high-current low-voltage type with a large octagonal finned heatsink. . See Jack Ward's site for more details on this device.	The RCA 2N96 is a very obscure device. It uses the same packaging as the 2N72, and bears the military marking "USA", suggesting that it too may have been the subject of a proof of manufacturing contract. I am seeking examples of this device.
The Germanium Products 2N97 and 2N97A were the first of a family of grown-junction NPN types up to 2N100 with increasing maximum frequency. They also bore Germanium Products RD series type numbers. I am seeking examples of these devices.	The Germanium Products 2N98 and 2N98A are the second in the family. See Jack Ward's site for more details on this device.	The Germanium Products 2N99 is an NPN switching transistor for computer circuit applications.
The Germanium Products 2N100 is an NPN switching transistor for computer circuit applications.	The Sylvania 2N101 is a PNP-alloyed high-current low-voltage type electrically identical to 2N68, but in a different packaging designed to "render it highly resistant to shock and vibration". This just means the Sylvania screw-mounted cylinder.	The Sylvania 2N102 is an NPN-alloyed high-current low-voltage type electrically identical to 2N95 but in Sylvania's screw-mounted cylindrical package.
The Germanium Products 2N103 is an NPN grown-junction switching transistor for computer circuit applications.	The RCA 2N104 is a PNP-fused transistor also made by Sylvania, for low-power AF amplification.	The RCA 2N105 is a sub-miniature low-power PNP AF type especially for use in hearing aids.
The Raytheon 2N106 is a low-noise PNP AF amplifier transistor.I am seeking examples of this device.	The General Electric 2N107 was introduced as an affordable hobbyist PNP AF device in late 1955. See Jack Ward's site for more details on this device.	The CBS 2N108 is yet another PNP general purpose AF amplifier type. I am seeking examples of this device.
The RCA 2N109 was a very successful commercial PNP AF type. See Jack Ward's site for more details on this device.	The Western Electric 2N110 is an N-type point-contact switching transistor, despite its modern appearance and relatively late 2N number. This transistor is probably the most common point-contact type to be found, presumably Western Electric manufactured many of them for the telephone system.	The Raytheon series 2N111 to 2N114 used a tall wide can in classic Raytheon iridescent blue. All were high-frequency devices, 2N111 to 2N113 for IF/RF amplification, 2N114 for use as a converter. Interestingly, they are dual-numbered, with both a standard 2N number and a Raytheon proprietary CK number. Some were made by other manufacturers, e.g. Tung-Sol.
The Amperex 2N115 is a PNP alloy-junction AF power transistor in an unusual package.I am seeking examples of this device. However, my image shows a rare dual-typed transistor made by Mullard of England, marked both 2N115 and OC16.	The CBS 2N116 is yet another PNP general purpose AF amplifier type. I am seeking examples of this device.	The Texas Instruments NPN types 2N117 to 2N119, introduced in 1956, were the first silicon transistors in the 2N series, and were also the first TI transistors hermetically sealed with a welded enclosure. As well as the standard commercial issue, there are US Navy versions designated USN2N117 etc. They were also made by Transitron.
The Sprague 2N159 appears in some data books as a point-contact transistor. If it existed, it possibly used the same "cigar tube" case as the Philco 2N62. I am seeking examples of this device.	There are higher numbered 2N types that are unusual and interesting. This image shows the extraordinary 2N3045 which is a dual transistor in an IC-style flatpack with only 6 leads used.