Discrete Semiconductors

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General Electric 4JA60AX544
 General Electric 4JA60AX544

The General Electric 4JA60AX544 (base P/N 4JA60) is a high current silicon diode of unknown specification.

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Honeywell H10A1XOC
 Honeywell H10A1XOC

The H10A1XOC appears to be an uncharacterized variant of the Honeywell H10 power transistor, introduced in 1957. The H10 is a large germanium PNP power transistor with a 15W power dissipation rating, hook lug leads and a large threaded mounting lug. Honeywell began producing power transistors in 1953 for in-house use in their various industrial automation systems. Although Honeywell was an early pioneer of germanium power transistors, their devices are uncommon and often overlooked in the pantheon of early transistor development.

Honeywell later produced similar commercial devices with standard RETMA part numbers: the 2N574 and 2N575, both rated at 25W.

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Hitachi DSS100A2R
 Hitachi DSS100A2R

The Hitachi DSS100A2R is an uncharacterized device, but appears to be a large power thyristor or other similar type of semiconductor.

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Kearfott 2N110
 Kearfott 2N110

Introduced by Western Electric in 1955, the 2N110 is a germanium point contact switching transistor similar to the original 2N21. The 2N110 is particularly robust for a point contact device, and is useful over a wide temperature range. The example pictured here was manufactured by Kearfott in 1970, long after point contact transistors had become obsolete. Kearfott is the only second source for the 2N110 currently known.

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Motorola 2N554
 Motorola 2N554

Introduced in the late 1950s, the Motorola 2N554 is a germanium PNP power transistor in a gold-plated TO-3 package. The 2N554 was originally intended for automotive applications, and was also the transistor featured in the first published design for a transistorized model train throttle.

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Philco 2N1158A
 Philco 2N1158A

The Philco 2N1158A is a germanium PNP micro alloy diffused transistor (MADT), an improved type of surface barrier transistor capable of operating at frequencies in excess of 200MHz. The example shown here is a U.S. Army variant.

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Philco HAW1943
 Philco HAW1943

The Philco HAW1943 is an unidentified device, but appears similar to the 2N1158A MADT.

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RCA 2N688
 RCA 2N688

The RCA 2N688 is an early silicon diffused junction thyristor in a TO-48 package, rated at 600V, 25A. The 2N688 is designed for high power switching applications.

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Raytheon CK718
 Raytheon CK718

Introduced in late 1952, the Raytheon CK718 germanium PNP transistor is believed to be the first mass-produced junction transistor. The CK718 was not made available to consumers, but was instead supplied exclusively to a number of hearing aid manufacturers.

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Raytheon CK722
 Raytheon CK722

The Raytheon CK722 germanium PNP transistor is a low performance bin of the CK718 shown above. The CK722 is regarded as the first low cost transistor available to consumers, and is the transistor used by Bulova engineer Max Hetzel during prototype development of the Accutron electronic timepiece.

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Raytheon 2N132
 Raytheon 2N132

The Raytheon 2N132 germanium PNP junction transistor is a miniaturized RETMA-numbered version of the CK725, first introduced in 1954. Designed for use in audio frequency preamplifiers, the 2N132 is a minuscule device. Despite its early metal can construction, its size is comparable to modern small signal transistors.

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Rheem Semiconductor RT5202
 Rheem Semiconductor RT5202

The Rheem RT5202 is a silicon NPN transistor of unknown specification, in a standard TO5 package.

Rheem Manufacturing Company, best known as a manufacturer of water heaters, followed in the footsteps of Fairchild Camera & Instrument by backing an early transistor start-up division in Silicon Valley. In March 1959, Fairchild Semiconductor's general manager Ed Baldwin and several other employees abruptly resigned, and established Rheem Semiconductor Corporation in Mountain View, California. Rheem soon began producing mesa transistors based on Fairchild's design. Fairchild then sued Rheem, and discovered intellectual property which had been removed from Fairchild by Ed Baldwin and his group. Fairchild and Rheem ultimately settled out of court, primarily due to uncomfortable similarities between Ed Baldwin's illicit activities and the events which led to the formation of Fairchild Semiconductor. Rheem ultimately agreed to not produce mesa transistors based on Fairchild's design.

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Sprague 2N128
 Sprague 2N128

Philco introduced the germanium PNP surface barrier transistor (SBT) in late 1953. SBTs gained rapid popularity due to their high frequency performance, and established Philco as a key early transistor manufacturer. The 2N128 is an early commercial SBT, introduced by Philco and later replicated first by Sprague and then other manufacturers.

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Sylvania 1N415C
 Sylvania 1N415C

The Sylvania 1N415C is a silicon point contact microwave mixer diode designed to operate at X-band frequencies. The example shown here is a pair matched at the factory for output voltage.

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Texas Instruments J44
 Texas Instruments J44

The Texas Instruments J44 is an early device of unknown specification. It is likely a silicon bipolar junction transistor.

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Western Electric 2N29
 Western Electric 2N29

The Western Electric 2N29 is an early production example of germanium NPN bipolar junction transistor (BJT) technology. In 1955, Western Electric introduced their first two production BJTs, the 2N27 and 2N28. The 2N29 followed in 1957. All three of these devices were derived from the orignal Bell Labs M-1752 BJT prototype.

Prior to Fairchild's introduction of the planar transistor in 1959, semiconductors lacked a protective silicon dioxide passivation layer to protect against internal contamination of the base-collector junction. Many of these early semiconductors, such as the 2N29, featured a hermetically sealed metal canister with an evacuation nipple.

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Western Electric GA52609
 Western Electric GA52609

The Western Electric GA52609 is a NPN alloy junction transistor of unknown specification.

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Western Electric GA53270
 Western Electric GA53270

Much like Hewlett-Packard, Western Electric's history is riddled with unidentified in-house part numbers. The uncharacterized GA53270 is a typical example of this phenomenon. Many Western Electric semiconductor part numbers are prefixed with GA, GF or F, generally accepted to indicate the parts were produced for a military or government contract. Other than the part number, the GA53270 appears externally identical to other Western Electric transistors from the same era, such as the 2N27.

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Western Electric GA53677
 Western Electric GA53677

The Western Electric GA53677 is a germanium PNP transistor of unknown specification.

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Western Electric 2N559
 Western Electric 2N559

The Western Electric 2N559 diffused-junction germanium PNP transistor is perhaps the first military-rated computer transistor. Released in 1957, the 2N559 is a rugged, highly reliable, high speed switching transistor, capable of operation in excess of 400MHz. The 2N559 features a diffused-junction mesa construction, is highly miniaturized, and is a distinctly mature device for its time.

The 2N559's numerous high-performance features, as well as Western Electric's ability to produce them in large quantities, resulted in their use in the Remington Rand UNIVAC Target Intercept Computer (TIC), whose logic circuitry employed 20,000 2N559 transistors.

Mechanization of Semiconductor Devices: 2N559 & 2N1094 - Quarterly Progress Report 17 (PDF)
Mechanization of Semiconductor Devices: 2N559 & 2N1094 - Quarterly Progress Report 22 (PDF)
Obsolete Lower Power & Switching Transistors Datasheet (PDF)

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Western Electric 2N1072
 Western Electric 2N1072

The Western Electric 2N1072 is a diffused junction silicon NPN mesa power transistor, specially developed for use in the Nike Zeus anti-ICBM missile system. The 2N1072 is a rugged device capable of high current, high frequency operation in high temperature environments. The 2N1072 was the first device to use the TO-38 package, a cold welded, vacuum-sealed canister.

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Western Electric 20D
 Western Electric 20D

The Western Electric 20D is a diffused junction silicon NPN power transistor rated at 1.5W. The 20D was widely used in Bell System telephone equipment.

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JAN2N1016C (Unknown Mfr.)
 JAN2N1016C (Unknown Mfr.)

Originally introduced by Westinghouse in 1959, the 2N1016C is a high purity silicon power transistor with a 1500W power dissipation rating. The example pictured here is a JAN variant, and the manufacturer is currently unknown.

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