TRANSISTOR MUSEUM™   

Historic Transistor Photo Gallery   

 

Transistor Size XN-1 and XN-2

 (3/8”L X 1/8”W X 5/16”H)

XN-3  (3/8”L X 1/8”W X 7/16”H)

 

Bottom View – No Other Markings or Packaging

 

MOTOROLA

XN-1 , XN-2 , XN-3

 

TYPE

Germanium PNP Alloy Junction

 

USAGE

Experimental 

 

DATE INTRODUCED

1954/5

 

CASE STYLES

Unpainted Silver Metal

 

AVAILABILITY

Rare (Limited Production)

 

HISTORIC NOTES

Although Motorola became one of the dominant semiconductor companies in the 1960s, and still retains a strong presence in this market today, early transistor work at Motorola is not well documented.  The first Motorola semiconductor development to make substantial industry impact was the germanium power transistor type, such as the 2N176, introduced in 1956.  This was a technology that saw widespread use in the automotive radio industry from the later part of the 1950s throughout the 1960s. In fact, there was earlier experimental germanium transistor development at Motorola. The types XN-1, XN-2 and XN-3 were all developmental germanium alloy junction transistors, shown above, from the 1954/1955 timeframe.  These were all crudely constructed devices, requiring detailed hand assembly.  The metal case appears to have been hand soldered at the bottom joint.  The XN-3 appears to have a slightly more “finished” appearance.  Schematics exist, dated 1955, showing the XN-2 in proprietary Motorola circuitry.   The XN-1, XN-2 and XN-3 series is quite rare, and most likely represents the earliest developmental germanium junction transistors made by Motorola.  There is no known packaging and there are no date codes stamped on the metal cases.  The units shown above are all functional, which suggests a reasonably effective environmental seal. 

 

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