RCA introduced the 2N404 in 1957, and this device was one
of the first of a series of highly successful germanium computer
transistors developed by RCA throughout the late 1950s. Dr.
Adolph Blicher managed the RCA group responsible for the 2N404,
building on his earlier work at the Radio Receptor company where he
developed the RR156 computer transistor. The 2N404 was soon adopted an as
“industry standard” and sold in the millions, with multiple companies
producing equivalent devices. Related transistors include the 2N269
(electrically equivalent to the 2N404, but using a different case), the
2N404A (which is a higher current/voltage version of the 2N404) and the
USAF 2N404 (qualified for military use). The 1960 Lafayette Radio
Semiconductor Directory lists the 2N404 as available from multiple
companies (RCA, GE, Raytheon and Sylvania) for between $2.50 and $3.00.
The 2N404 continued to be available throughout the 1960s/70s. The 2N404
remains in use today by hobbyists and experimenters, primarily as an audio
or general purpose transistor – this modern usage is a fitting tribute to a
classic germanium device, introduced over 50 years ago!