TRANSISTOR MUSEUM™   

Historic Transistor Photo Gallery   

 

Transistor Size (1/4” OD X 1/2”)

Similar to Standard TO-5 Case.  No Packaging.

 

Top View of Marked and Unmarked Units

 

MOTOROLA

2N311

 

TYPE

Germanium PNP Alloy Junction

 

USAGE

Low Speed Switching/Computer   

 

DATE INTRODUCED

1957

 

CASE STYLES

Unpainted Silver Metal

 

AVAILABILITY

Rare (Limited Production)

 

HISTORIC NOTES

Low power germanium transistor types were not produced by Motorola in substantial volume until the early 1960s, when the high speed mesa devices, such as the 2N705 were introduced.  The 2N311, shown above, is a unique transitional type which illustrates the still evolving and crude manufacturing practices of the late 1950s.  For example, note the small circular spot on the top-side of each of the units above – this was formed by an operator manually melting a small drop of solder on the case, to seal a small evacuation hole which was used to fill the transistor can with nitrogen.  Note also the somewhat crude nature of the epoxy sealing material used to encapsulate the bottom of the device (top right photo).  The 2N311 was produced by Motorola in low quantities and was out of production by the early 1960s.  It was listed in several early reference books as a low speed computer switch, equivalent to the better known 2N404.  No commercial pricing information is available.  The marked units shown above are from week 52, 1957; the unmarked units have no typing or date code information.  These devices are all functional, which suggests a reasonably effective (although crude) environmental seal.

 

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