Last Updated March 22, 2016.


The Transistor Museum™ Store has been established to provide an easily accessible (and affordable) source of unique and historic transistors, diodes and integrated circuits from the early days of this exciting technology.  Use the table below to explore what’s available and to compare the different types.  In each case, you’ll find a link which will take you to more details about the specific museum offering and how to purchase. To aid historians, experimenters, hobbyists and anyone else interested in learning about transistors, each Transistor Museum™ device is supplied with historical information including circuits, technical description and photos.  The Museum Store will soon be expanding as we add many more unique and historically important semiconductors of all types.  In addition, every device that you purchase will now include a Transistor Museum™ Historic Semiconductor Fact Sheet, which is a full page-sized document containing a collection of useful facts, pictures and commentary about the specific device.  You won’t find anything like this elsewhere, and you’ll likely spend many rewarding hours reviewing this unique material and learning about semiconductor history.


See all the historic semiconductors in the store below.  If you’d like to place an order or have any questions, please contact us at




Transistor Museum Historic Semiconductors Research and Collecting Kit

This kit is one of a continuing series of semiconductor research and collecting kits developed by the Transistor Museum. The Historic Semiconductors Research and Collecting Kit provides comprehensive technical descriptions, historical commentary and timelines, and photographs of the famous diodes, transistors and integrated circuits that were first developed in the 1950s, 1960s and 1970s and which have had such a profound effect on the world of today’s electronics. This wealth of research information should be of great interest and value to the modern-day historian, engineer, researcher and electronics hobbyist. Also included in this unique Transistor Museum kit are 50 vintage, historic and collectable mid-20th century semiconductors, all documented with key data and photographs.   


History of Transistors

Volume 1




If you are an Historian, Engineer, Experimenter, Researcher or Hobbyist interested in early semiconductor technology, this unique publication and classic 1950s/60s hobbyist transistor kit is a “must-have”.  You’ll find that this material (and more coming soon from the Transistor Museum) is an unparalleled way to increase your knowledge, enjoyment and active participation in the exciting field of semiconductor history. 


Your historic transistors, photos, descriptive text and storage envelopes are contained in an expandable three-ring report binder.  The display envelopes are securely stored in plastic sheet holders at the rear section of the booklet.  Archival quality sheet protectors are used for storage of photographic and text pages.  Shown below is a summary of what you’ll receive:





2N170, CK78X












Your historic diodes, photos, descriptive text and storage envelopes are contained in an expandable three-ring report binder.  The display envelopes are securely stored in plastic sheet holders at the rear section of the booklet.  Archival quality sheet protectors are used for storage of photographic and text pages.  Shown below is a summary of what you’ll receive:
















History of Crystal Diodes

Volume 1




If you are an Historian, Engineer, Experimenter, Researcher or Hobbyist interested in early semiconductor technology, this unique publication and classic 1950s diode kit is a “must-have”.  You’ll find that this material (and more coming soon from the Transistor Museum) is an unparalleled way to increase your knowledge, enjoyment and active participation in the exciting field of semiconductor history.


IBM Germanium PNP Alloy Junction

Experimental Transistor   


IBM AJ side View Blue 2 Edits 2


Master Photo Closeup 1 edits


Your IBM germanium transistor will be of the type shown in the photos above.  You can use your historic 50 year old device for display purposes or in actual circuitry to demonstrate a classic PNP germanium transistor.   




Historical Background:  IBM established an aggressive transistor development program in the early 1950s and continued with a substantial engineering and production effort throughout the decade.  During the decade from approximately 1952 to 1962, IBM developed and manufactured a variety of germanium transistor types for use in their commercial computers.  Primary types of computer transistors produced by IBM during this timeframe included alloy junction and graded base/drift, and both NPN and PNP configurations were made.  By the mid-1960s, IBM no longer manufactured germanium transistors, instead using devices manufactured by leading semiconductor companies such as Motorola and Texas Instruments.  Your Transistor Museum™ transistor (examples shown at left) is from an experimental 1959 lot of alloy junction transistors produced to evaluate new production and test equipment.  Many of these units have hand-painted color codes which were likely used to track performance characteristics.  These are PNP alloy junction types and have similar characteristics to IBM types 25 and 33, which are general purpose PNP alloy junction transistors.



Additional Transistor Museum™ Links:

Hannon Yourke Oral History



Historical Background:  Approximately ten years after the first public announcement of the transistor in 1948, this new technology had matured to the point that devices of reliability and performance suitable for military use were available.  The Nike Zeus program was the first large scale missile system to use transistors in preference to vacuum tubes.  Bell Labs was heavily involved in the Nike projects, beginning with Nike Ajax in 1946.  The 2N1072 silicon transistor was available to contractors and subcontractors of U.S. government projects, and this included the Nike Zeus anti-ballistic missile program, where high reliability and performance were required. Bell Labs and Western Electric had been designated contractors by the U.S. government for the Nike Zeus missile program and the 2N1072 was employed extensively in this system.  Both germanium and silicon transistors were used in the Nike Zeus, and the 2N1072 mesa (double diffused) technology represented the best that could be manufactured in the late 1950s – 2 amp switching currents up to 70MC.  These high reliability transistors cost many times more than commercial devices.


Additional Transistor Museum™ Links:

Homer Coonce Oral History


Western Electric Double Diffused Silicon NPN Mesa 2N1072 Transistor


New 2n1072 Closeup 3


2n1072 closeup Ad from Electronics

Typical 2N1072 transistors are marked as shown above - the “144” date code denotes 1961 week 44.  Western Electric registered the 2N1072 with JEDEC in 1961.  Note the unique metal case style, listed as TO-38.



Westinghouse 2N60 2N609

Germanium PNP Alloy Junction

Audio Transistor   



Westinghouse Red Bckgnd 2N60 and 2N609 Front View and Date Code Update 2


Blue and Gold Westinghouse Trannies Group 1


Use your 2N60 as a general purpose audio amplifier – the 2N609 is a higher gain equivalent to the 2N60 and can be used in similar audio amplifier applications.  These are rare and historic devices and will make a terrific addition to your collection of early semiconductors.  



Historical Background:  During the late 1950s and 1960s, Westinghouse became a world leader in the manufacture of high power silicon transistors and rectifiers.  Research and manufacture of germanium transistors had been started in the mid-1950s, but was not a major business for Westinghouse.  Of note is the manufacture of low frequency (audio and IF) germanium transistors, primarily to support the substantial Westinghouse commercial radio manufacturing business.  Your Westinghouse 2N60/2N609 transistor represents an important, though short-lived, chapter of semiconductor history.  Early commercial Westinghouse radio transistors are easily identified by the brilliant blue iridescent case color – this was used from the mid-1950s until 1959, when the gold plated case style was adopted.  Both styles are shown at left. Your 2N60 or 2N609 historic transistor was manufactured during the early weeks of 1960 at the Westinghouse Semiconductor manufacturing facility in Youngwood, Pa.  The 2N60 is as audio output device equivalent to the more common 2N185 from TI and the 2N109 from RCA. 





Historical Background:  The RCA 2N247, introduced in 1956, was the first RCA drift transistor, and provided stable operation up to 30 Mc.  RCA developed a complete line of drift transistors in the 1950s and 1960s, including the high performance 2N384, which could operate reliably up to 100 Mc.  These devices found widespread use in commercial radio receiver circuits and also in many types of high frequency military and industrial equipment.  RCA’s drift technology was a recognized industry leader for high frequency use in the late 1950s and early 1960s.  These devices were used extensively in high frequency service in commercial, industrial and military applications. RCA Drift transistors are germanium p-n-p alloy junction types which are specifically designed and controlled for operation in mass-produced military and commercial equipment and in entertainment type receivers operating at frequencies up into the VHF band. 



Additional Transistor Museum™ Links:

2N247 PhotoGallery

RCA 2N247 & 2N384

Germanium PNP Drift Transistors


2N247 2N384 with Package


2n247 and 2n384 Closeup


Use your historic drift transistors for all types of high frequency radio and oscillator circuits and re-create leading edge 1950s semiconductor technology.



General Electric 1N3712/TD-1 Germanium Tunnel Diode


GE 1N3712 Tunnel diode Closeup Photo 2


Your GE 1N3712/TD-1 is a general purpose device, well suited for experimentation as a very low power amplifier or oscillator.  You’ll be intrigued with this 45 year old germanium device, which functions by the mechanism of quantum tunneling of electrons. Circuit design with the tunnel diode is very challenging, since the tunnel diode exhibits an unusual characteristic known as negative resistance, which is found in only a few other obscure devices (point contact and unijunction transistors, for example).




Historical Background:  The tunnel diode is a truly unique semiconductor, with a number of interesting characteristics and an unusual historical past.  Developed by Leo Esaki at Sony in 1957, and made public in 1958, the tunnel (or Esaki) diode was the first device that demonstrated the validity of quantum physics.  Very high switching speed (quantum tunneling) and the performance attribute known as negative resistance appeared to position the tunnel diode as the successor to the transistor for many applications.  Although several companies invested heavily in tunnel diode development, this unique technology has found only niche applications and since the mid-1960s has been largely seen as a technological curiosity.  Despite the lack of large scale commercial success, tunnel diode technology continues to generate substantial interest across a broad range of semiconductor researchers, engineers, hobbyist and historians.  GE was an early and primary supplier of tunnel diodes and invested heavily in this technology throughout the late 1950s and into the 1960s.  The first and most comprehensive industry publication on tunnel diode technology was the 1961 GE “Tunnel Diode Manual”, modeled after the famous GE Transistor and SCR manuals. 



Historical Background:  Texas Instruments introduced the 2N339 – 2N343 line of medium power silicon grown junction transistors in 1957.  This is a very early timeframe for silicon technology, as only three years had passed since the introduction of the first commercial silicon transistors by TI in 1954.  During the 1950s, transistor technology was advancing rapidly, and the grown junction technology used for these first silicon transistors was soon superseded by more advanced technologies such as diffused/mesa and planar.  The military was a major user of these early silicon transistors, and prices were quite high as the demand for this new technology was expanding rapidly.  For example, the 1960 price for a 2N343 from TI was $30. That’s over $200 in 2012 prices.  With this type of financial incentive, other companies soon began competing with TI.  Transitron was the major second source supplier for the 2N339 – 2N343 line of transistors, and sold millions of these devices into the 1960s.  Transitron played an important role in 1950s/1960s semiconductor history, and devices such as these early 1960s 2N343 transistors are collectable and historic. 



Additional Transistor Museum™ Links:

Transitron History - David Bakalar


 Transitron 2N343 Silicon NPN

Grown Junction Transistor


Front View Two 2N343 Edits 1


The Transitron 2N343 transistors included in your order are quite historic and represent the first silicon transistor technology.  These units are over 50 years old and have been tested to ensure performance comparable to 1960s grown junction technology.  These devices offer a unique and educational view back to a major and historic milestone in transistor history.  Suggested experimental applications include medium power audio amplifiers, general purpose low level switches, and comparison circuits with modern silicon devices.



Tung-Sol 2N63 2N64 2N65

Germanium PNP Alloy Junction

Hobbyist Transistor

CK722 and 2N107


2N63 and 2N64 with Package edits


Your Tung-Sol 2N63, 2N64 and 2N65 transistors are dated for the 1950s and 1960s, as shown above.  The 2N63 is a direct electrical equivalent of the Raytheon CK722 and the GE 2N107 hobbyist transistors.  The 2N64 matches the higher performance levels of the Raytheon CK721 and the RCA 2N109.  Tung-Sol transistors have a unique “Robin’s Egg Blue” case and a very distinctive orange and purple cardboard package.  These are highly collectable and historic semiconductors.  Use your 2N63 for all CK722 and 2N107 hobbyist circuits.  Performance will be just as designed in the 1950s.  




Historical Background:  Raytheon initially released the 2N63/64/65 line of general purpose germanium transistors in the mid-1950s.  Both editions of the famous Raytheon Transistor Applications Booklets have spec sheets for this line of devices. The electrical specs for the 2N63 are equivalent to the famous CK722 hobbyist transistor and the 2N64 exactly matches the CK721.  Raytheon was advertising the virtues of “hermetic sealing” for the 2N6X line of transistors, to note the improvement of metal casing and air tight seals to overcome some of the difficulties of the earlier black plastic cases of the first CK722s.  Tung-Sol Electric was an active manufacturer of germanium semiconductors in the 1950s, starting first with diodes and then developing PNP alloy junction transistors.  The first “2N” numbered Tung-Sol devices were the 2N63, 2N64 and 2N65 series of transistors, with tentative data sheets available in April 1957.  These were general purpose audio transistors, based on specs and JEDEC numbering following similar devices first released by Raytheon in 1956.  Tung-Sol spec sheets from the time list the 2N63 as a general purpose replacement for the famous GE 2N107 hobbyist transistor.


Additional Transistor Museum™ Links:

2N65 PhotoGallery




Historical Background:  The Hytron Radio Tube company, a vacuum tube manufacturer since 1921, was purchased by Columbia Broadcasting System (CBS) in the early 1950s.  CBS was interested in establishing a presence in semiconductor and vacuum tube manufacturing, likely to support their primary radio/TV entertainment business, and Hytron probably appeared to provide an excellent entry vehicle.  By late 1952, CBS was manufacturing germanium diodes and transistors at the Hytron facility in Lowell Ma.  Various device types, labeled as “CBS” or “CBS/Hytron”, were in production for approximately 10 years (until the early 1960s), when CBS exited the semiconductor manufacturing field.  From a historical perspective, CBS/Hytron represents a noteworthy chapter in early semiconductor device development – this “start-up” produced superior germanium devices (point contact transistors, junction transistors, diodes, and was especially known for germanium power transistors) for over a decade. Remaining CBS devices represent an excellent view into the best of early germanium technology.



Additional Transistor Museum™ Links:

2N38 PhotoGallery

CBS 2N38 Germanium PNP

Alloy Junction Historic Transistor


1955 CBS 2N38 Closeup Photo 4


 The 2N36, 2N37 and 2N38 are germanium alloy transistors, intended for use as general purpose audio amplifiers.  These devices were made on the same manufacturing line and were sorted and labeled, based on gain – the 2N36 had the highest gain and the 2N38 had the lowest gain.  Equivalent transistor types of the time from other manufacturers would have been the Raytheon CK722, the Sylvania 2N34 and the GE 2N107.  CBS/Hytron was an early pioneering transistor company and produced superior germanium devices, but only a few years.  Your 50+ year old transistor is still functional and can be used in most small signal germanium PNP classic circuits.



GE 2N43 2N44 2N45 Germanium

PNP Alloy Junction Transistor


Three 2N43s GE


The GE 2N4X types were widely used by the military throughout the 1950s and 1960s, with the 2N43A having the distinction of being the first transistor qualified by the USAF (in 1955).  These are excellent devices and you can use them as terrific general purpose germanium transistors for most all low frequency applications. 




Historical BackgroundIn mid-1953, General Electric (GE) made an early commercial entry into the new field of junction transistors with the 2N43/44/45 line of germanium alloy junction devices.  These were rugged, reliable transistors enclosed in the now classic “pinched top” metal case.  All these devices were made on the same manufacturing lines, with a gain test process used to sort the transistors into the appropriate 2N4X categories.  “Leftovers” from the 2N4X line, which failed to meet minimum specs, were sold as the famous 2N107 hobbyist transistor.  



Additional Transistor Museum™ Links:

2N43 PhotoGallery


Historical BackgroundSoon after the invention of point contact transistor technology at Bell Labs in 1947, William Shockley developed the theoretical basis for the junction transistor, and by 1951, the first experimental germanium junction transistors had been produced.  By 1952, Western Electric had implemented early production junction devices and registered the 2N27, 2N28 and 2N29 type numbers with the current industry standards association (RTMA, later to be known as JETEC/JEDEC).  The 2N27 and 2N28 were in large scale production by 1955, followed by the 2N29 in 1957.  These historic types are excellent examples of the first junction transistor technology (known as grown junction), and represent the “state of the art” for mid-1950s semiconductors.



Additional Transistor Museum™ Links:

2N27 PhotoGallery

2N29 PhotoGallery

Western Electric 2N27 2N29 Germanium NPN Grown Junction Historic Transistors


2N27 Closeup Photo 4 with Level Adjust Lightened


The Western Electric 2N27, 2N28 and 2N29 were the first junction transistor types registered with the industry standard “2N” RTMA numbering system.  The earlier 2N21 thru 2N26 types were also registered by Western Electric, but were point contact devices.  Indicative of the rigorous manufacturing and quality standards implemented by WECO, your 2N27 and 2N29 units, although 50 years old, are still functional. These are truly historic transistors!



Texas Instruments Germanium

Radio Transistors

Classic Devices from the 1950s


Three TI Germanium Radio Transistors LoRes


Unique and historic germanium radio transistors from Texas Instruments, the company best known for silicon! Use these classic 1950s devices to build your own transistor radio, audio amp, or hobbyist project.



Historical Background:  TI was a major supplier of germanium transistors used in radios manufactured by many companies in the 1950s, including Bulova, Emerson, Heathkit, Magnavox, Regency, and Zenith.  TI initially entered this market in 1954, when the first all transistor radio, the Regency TR1, was jointly developed by TI and introduced in Dec 1954.  TI supplied a complete range of these types of transistors, suitable for all elements of radio circuitry, such as audio, I.F. amplifier and converter oscillator. TI continued to manufacture and sell these unique germanium radio transistors into the 1960s.  You can use these classic germanium devices to repair your favorite old-time transistor radio, or to build a circuit from that timeframe with a truly historic transistor.



Additional Transistor Museum™ Links:

2N172 PhotoGallery



Historical Background:  In 1955, GE announced the introduction of the 2N169. This type was originally intended for use in commercial radios as an IF and reflex amplifier, but its use was later expanded as a general purpose NPN type for multiple applications.  The 1957 2nd edition of the GE Transistor Manual documents the 2N169 for use in a hobbyist circuit, and later additions of the GE Transistor Manual identify the 2N169 as a general purpose NPN germanium “workhorse” equivalent to such other well known types as the 2N35 and 2N229.  If you are building a 1950s vintage electronic project or repairing a radio from that timeframe, the 2N169 is an excellent choice for a solid, general purpose germanium transistor, with performance characteristics authentic to the early days of transistor technology.




Additional Transistor Museum™ Links:

2N169 PhotoGallery

GE 2N169/169A Germanium NPN

Grown Junction Transistor

General Purpose Vintage 1950s “Workhorse”


2N169 Closeup Photo 1


Authentic 1950s germanium transistor technology. These devices were very well made. Electrical performance is quite uniform and should easily match your requirements for historic transistor hobbyist projects.



Raytheon 1950s Germanium PNP Alloy Junction Transistor (BLUE)


Blues with Blue Background 2


Historic iridescent BLUE Raytheon germanium transistor.  Unique to the early days of 1950s transistor technology. Ready to use in your favorite vintage project.




Historical Background:  Raytheon was the early leader in 1950s high volume germanium transistor production, beginning with the CK718 hearing aid devices in 1952.  In 1955, Raytheon began using a distinctive iridescent blue metal case for all germanium transistor production – this style was unique to Raytheon and lasted only until the late 1950s.  Historians and hobbyists still find this 50 year old technology highly desirable.



Additional Transistor Museum™ Links:

CK722 Blue PhotoGallery

CK722 Webpage






Historical Background:  The first germanium junction transistors, beginning in the early 1950s, were primarily low frequency audio devices.   There was substantial research to develop higher frequency transistors to be used in computers.  RCA initially offered the 2N139/140 series, but entered the computer transistor market in a big way in 1957 with the 2N404. This was a very successful transistor, which sold in the millions of units in the 1950s and 1960s, and was second-sourced by numerous companies. The 2N404 is still used today by experimenters and hobbyists for germanium audio and general purpose circuitry.



Additional Transistor Museum™ Links:

2N404 PhotoGallery

Germanium PNP Alloy Junction

Computer Transistor Type 2N404


2N404 Horiz Top View


Historic 1950s/60s vintage germanium computer transistor.  One of the most successful and widely available germanium devices. Use yours for digital logic or germanium audio.



Germanium PNP Micro Alloy Diffused Base (MADT) Computer and High Speed Switching Transistor Type 2N501


2N501 GI 1964 Closeup 2


Historic 2N501 MADT transistors were the “Workhorse” for germanium digital computer and high speed switching applications in the late 1950s through the 1960s.




Historical Background:  One of the first transistors available for high speed operation was the surface barrier transistor (SBT) developed by Philco in 1953.  Improvements to the SBT technology lead to even higher performing MAT and MADT transistors. This latter type, Micro Alloy Diffused Base Transistor, was introduced by Philco in the late 1950s, and established the 2N501 as the “workhorse” for high speed digital and switching applications.  Several other transistor companies responded to this sales success with second source versions of the 2N501, including Sprague, General Transistor, General Instrument, CBS and ETCO.



Additional Transistor Museum™ Links:

2N501 PhotoGallery




Historical Background:  The earliest transistors used a technology known as Point Contact – this was the first type invented at Bell Labs in 1947.  Shockley’s junction transistor technology replaced the point contact type, which was obsolete by the mid-950s.  These 2N110s were manufactured by Western Electric for use by the military and Bell System phone equipment in the 1950s.  Each of these historic point contact devices has been tested and is guaranteed to work.  Your 2N110 (either black-cased, or grey) should function as designed in circuits developed to demonstrate the unique characteristics of point contact technology, including negative resistance.



Additional Transistor Museum™ Links:

2N110 PhotoGallery


 Western Electric 2N110

Point Contact Transistor


New 2N110 Grey and Black Closeup 2 Updated


The 2N110 is a truly historic device.  These are rugged and stable, and reflect the highest level of performance that could be achieved with the original point contact transistor technology.



Sylvania 1N34A &

Raytheon CK705/1N66 Germanium Diodes


1N34s Just Two Closeup 2 Rotated


Your classic 1950s germanium point contact diodes have been tested and offer 1950s performance for your next radio project!




Historical Background: Introduced by Sylvania in 1946, the 1N34 germanium diode has been in production ever since and continues to be the most popular and universally recognized diode available.  By the early 1950s, the 1N34 was manufactured by other companies, including CBS-Hytron, Radio Receptor, RCA and Raytheon. Both Sylvania and Raytheon marketed the 1N34 heavily to the hobbyist and experimenter market, and published numerous booklets containing 1N34 construction projects – best remembered is a simple AM radio, using the 1N34 with very few other parts.



Additional Transistor Museum™ Links:

Raytheon CK705 Diode PhotoGallery



Historical Background: GE developed one of the most famous hobbyist transistors when the 2N107 PNP germanium alloy junction device was announced in 1955.  In the following year (1956) GE introduced the NPN germanium grown junction unit, labeled the 2N170.  With performance adequate for front-end radio circuits, the 2N170 was a natural companion for the 2N107 audio type.  Relive the early days of home-built transistor radios!  



Additional Transistor Museum™ Links:

2N170 PhotoGallery




  General Electric 2N170

Hi Freq RF Transistors


2nd New 2N170 Museum Store


Original GE hobbyist circuit and history included!





Surface Barrier & MADT

 Hi Freq and Computer Switching Transistors


2N128 and 2N588 Photos for museum Store


Early radio schematic and original surface barrier patent information included.




Historical Background: These were the first commonly available high frequency transistors of the 1950s - made famous by Philco. Early germanium transistors performed poorly at frequencies above audio, and as such, had limited applications. Philco developed a very successful transistor technology, known as surface barrier, which resulted in germanium suitable for high speed use in computers and radios. Philco remained a dominant transistor company into the mid-1960s, based largely on this pioneering technology.



Additional Transistor Museum™ Links:

Surface Barrier PhotoGallery


Historical Background: Raytheon was the leading supplier of the first transistors to hearing aid manufacturers, starting in 1952.  These first Raytheon transistors were black epoxy cased units, labeled as CK718.  Transistor technology was developing rapidly and the next generation of smaller metal cased units appeared in 1955.  Still further size reduction and improved performance resulted in the 1957 vintage unit supplied with your Transistor Museum™ order.  Surplus Raytheon CK78X transistors were encapsulated inside larger blue or silver metal cases and marketed as the popular CK722 hobbyist transistor. (See the top photo at right).  Use these just like classic “Mini CK722” PNP germanium alloy transistors from the 1950s.  These are original Raytheon hearing aid transistors and are exactly the same type of transistors that were used “inside” the famous blue and silver CK722s.  This is an inexpensive way to experiment with circuits from the days of the first hobbyist transistors!



Additional Transistor Museum™ Links:

Silver CK722 PhotoGallery

Blue CK722 PhotoGallery



Raytheon CK78X Hearing Aid Transistors (Mini CK722)


Evolution of Early CK Transistors Photo 4 Edits


New CK78X Museum Photo Cropped


Your CK78X transistors will be of the style shown directly above – miniature unmarked silver units.  These are historically important because this exact type of surplus hearing aid transistor was used by Raytheon to extend the market life of the famous CK722 hobbyist transistor.  As shown in the top photo, the miniature hearing aid transistors were mounted inside a larger blue or silver metal case and labeled “CK722”.



  Raytheon CK718 Hearing Aid Transistor


Early CK718 in Tube Socket Bright


Circuit and History Included!




Historical Background: Truly Historic!  These were developed by Raytheon, starting in 1952, for use in hearing aids. The CK718 was sold only to hearing aid manufacturers (such as Zenith) and only for a short time (thru 1955).  Your CK718 has been tested and is supplied with a vintage Sub-Mini vacuum tube type socket. A perfect opportunity for experimenting with one of the earliest commercial transistors.



Additional Transistor Museum™ Links:

CK718 PhotoGallery



Historical Background: The GE 2N107 (introduced in 1955) was one of the first low-cost hobbyist transistors available. According to the press release which announced the 2N107, “A new transistor, designed to meet the demands of radio amateurs, hobbyists and experimenters for a stable, inexpensive transistor has been placed on the market by the General Electric Co…… the suggested distributor price of well below $2 for the new 2N107 transistor makes it the least expensive of any transistor currently available.”  This transistor became a favorite with hobbyists and experimenters, and there were hundreds of “build it yourself” articles using the 2N107 published over the decades.  You won’t find a better transistor for your vintage projects.    


Additional Transistor Museum™ Links:

2N107 PhotoGallery

Carl David Todd Oral History


  General Electric/ETCO 2N107

Hobbyist Audio Transistors


Five 2N107s Photo 4


GE first introduced the 2N107 in 1955 with the classic “pinched-top” metal case, shown above second from right.  By 1957, the more modern “top-hat” was used (far right).  In the 1960s and 1970s, ETCO sold the 2N107 in the standard silver TO-5 case (center).  Several radio supply companies (Radio Shack, Lafayette, Poly-Paks) sold unlabeled 2N107 style devices (left and second from left) for many years.




  RCA 2N109 & 2N406 Germanium Audio Transistors


2N406 and 2n109


Circuit Included for 1950s Germanium Preamp.




Historical Background: These are vintage germanium audio transistors from the 1960s.  These classic devices were manufactured by RCA for use in a variety of early transistorized audio applications, including transistor radios and the first true “Hi-Fi” transistorized preamps. This is a unique opportunity to explore the World of Germanium Audio!



Additional Transistor Museum™ Links:

2N109 PhotoGallery



Historical Background: The unijunction transistor is a unique single junction device, developed at GE in the early 1950s, and originally known as the “double base diode”. GE was the dominant unijunction manufacturer throughout the 1950s and 1960s, with many millions of units sold.  Applications ranged from oscillators to switching circuits.  Your Transistor Museum™ packet will contain a vintage unijunction transistor and original application.


Additional Transistor Museum™ Links:

2N489 PhotoGallery

  Vintage GE 2N489 - 2N494

Silicon Bar Unijunction Transistors


2n489 and 2n491 Blue Background


Early N-Type Silicon Bar Unijunction Transistors.



  TI Polaris Missile R212

Germanium PNP Alloy Junction Transistor


R212 Closeup Photo for Museum Final


Tested for a minimum gain of 80.




Historical Background: These gold plated, high quality germanium transistors were manufactured for the Polaris missile program by Texas Instruments in the 1960s/70s.  Use these in a wide variety of germanium circuit applications and you are sure to get excellent results. Add a bit of history to your next project. 



Additional Transistor Museum™ Links:

TI R212 PhotoGallery




Historical Background: Vintage germanium hobbyist transistors from the 1950s/60s.  These classic devices were manufactured by Sylvania for use in a variety of low cost early transistorized hobbyist projects.  Dozens of circuits were published in hobbyist magazines, describing such projects as Radios, Computer Circuits, Geiger Counters, Light Flashers and Code Oscillators.



 Sylvania 2N229 NPN Germanium Alloy Junction Hobbyist Transistor


2N229 Front View


Circuit Included for 1950s germanium radio.


 Texas Instruments 2N1149

National Semiconductor 2N1150 Vintage Silicon Grown Junction Transistors


2N1149 Closeup 6


Experiment with the first silicon transistor technology.  Device description included!



Historical Background: These vintage devices from the 1960s represent the first type of silicon transistor technology available, known as grown junction.  TI was the first to commercialize silicon transistors (in 1954) and the devices shown here provide a unique opportunity for the experimenter/historian to learn about this historic technology. These transistors have been tested and are “ready to go” in your own vintage silicon circuit.





Historical Background: This is a classic and historic transistor from the early days of solid state digital computers. Used by Univac and by the U.S. Military, the 2N167 is a high reliability, switching device that met the needs of the first transistorized computers.  Build your own digital circuits with the included schematics.



Additional Transistor Museum™ Links:

2N167 PhotoGallery

 GE 2N167/2N167A Germanium NPN

Grown Junction Computer Transistor


2n167 Front View


One of the first commercial NPN transistors designed for computer usage.



Fairchild uLogic® 923

RTL Integrated Circuit

J-K Flip-Flop


Two 923s Fiarchild RTL Micrologic Integrated Circuit


Your uLogic 923 integrated circuits as shown above are 50+ years old and represent the earliest type of integrated circuits made available commercially in large quantities by Fairchild.  You can use these devices to experiment with digital logic and computer circuits, or as replacements for products sold in the 1960s and 1970s that used these unique devices.  Your historic Fairchild uLogic 923 integrated circuits are “New Old Stock” and should function as designed.



Historical BackgroundBeginning in 1961, Fairchild  offered one of the first Integrated Circuit product lines for commercial sale.  These ICs were silicon and contained a few transistors, diodes, resistors and even capacitors on the silicon “chip”.  These ICs implemented basic logic functions and used a type of circuitry known as RTL (Resistor Transistor Logic). The 923 is an RTL IC containing 15 transistors which performs the logic function defined as J-K Flip-Flop.  Initial prices were quite high ($50 for example), but began to fall as more companies entered the market.  Fairchild used the copyrighted name MicroLogic® and uLogic® for their first ICs.  Your 923 units are Fairchild uLogic RTL ICs from the early 70s.  Your units are type 923EC, which indicates commercial temperature range and epoxy case.  There are eight leads on the 923, with details provided in your documentation.



This is a variety pack of four 1950s/1960s vintage germanium transistors.  You’ll receive PNP, NPN, Audio and RF/IF Hi-Freq Types.  Includes schematics, circuit ideas, and specifications for your transistors.  Each transistor is individually packaged (See the Photo on the Left for a Sample of Two of the Four Types Included). This Experimenter’s Pack is an exciting and authentic way to learn about early transistor circuits.







 Germanium Transistor

Experimenter's Pack #1


XP1 Pack Samples


Vintage Transistors Ready to Use!  Several Pages of Historic Circuits Included!



“The Story of the CK722”

by Jack Ward

If You Were an Electronics Hobbyist in the 1950s and 1960s, then You’ll Thoroughly Enjoy This Exciting New Book.


“TI, the Transistor and Me”

by Ed Millis

This New Book is Immensely Entertaining and Tells the Story of Early Transistor Development at Texas Instruments.    


Copyright 2001-2016 by Jack Ward.  All Rights Reserved.