Artifact Details

Title

CK721 Germanium transistors

Catalog Number

102757308

Type

Physical Object

Date

1953 - 1954

Manufacturer

Ratheon Semiconductor Division

Place Manufactured

US

Identifying Numbers

Model number CK721

Dimensions

overall: 1/4 in x 2 in x 2 3/4 in

Description

The object consists of nine pieces. Date codes: 406 (1954, week 6); 426 (1954 week 26); 406 (1954 week 6); 434 (1954 week 34); 332 (1953 week 32);419 (1954 week 19); 434 (1954 week 34); 426 (1954 week 26); 332 (1953 week 32).

Per Jack Ward, Transistor Museum -
'Raytheon CK721 (9 pieces), germanium PNP alloy junction transistors. Better performing and more expensive version of the CK722, intended for low cost audio and general purpose applications, beginning in early 1953. As with the CK722, these early CK721 units were fallouts from the CK718 hearing aid production lines. Date codes: 406 (1954, week 6); 426 (1954, week 26); 406 (1954, week 6); 434 (1954, week 34); 332 (1953, week 32); 419 (1954, week 19); 434 (1954, week 34); 426 (1954, week 26); 332 (1953, week 32). Common - with tens of thousands sold to hobbyists and experimenters as general purpose, affordable and readily available transistors - first as black epoxy units as shown below, and later replaced by iridescent blue case units, beginning in mid-1950s, and later silver case units in early 1960s. The early date code units (332) are not common, as these are from very early production lots. "

Category

Component/Semiconductor/transistor

Credit

Gift of Pat Belotti

Lot Number

X7957.2017