After the 1951 Bell symposium, many firms took out a license, some old-established tube manufacturers like RCA, Raytheon, Sylvania and General Electric, and some brand-new startups like Texas Instruments and Transitron. Most started by producing point-contact transistors, which at the time had better high-frequency behaviour than junction types. However, the junction transistor soon became superior in performance, and was simpler and more consistent to manufacture.
The first commercial junction transistors were primitive by modern standards, with a maximum collector-emitter voltage of 6 volts, and a maximum collector current of a few milliamps. Particularly notable was the CK722 from Raytheon in 1953, the first mass-produced transistor, which made solid-state electronics affordable to the amateur constructor. Improved types were soon developed, extending frequency response, lowering noise levels, and increasing power dissipation.
The earliest transistors were made from germanium, a metallic semiconductor. However, it was known that silicon offered advantages in terms of breakdown voltage and power handling ability. Silicon was more difficult to refine because of its higher melting point, but by 1955 the first silicon transistors were commercially available. Texas Instruments played a leading part in the early development of this technology.
The American semiconductor industry was remarkable in that standardisation of nomenclature and packaging occurred relatively quickly. The first and pre-eminent standard series of devices from many manufacturers was the 2Nseries of transistors, encompassing firstly germanium and then silicon types, including a number of point-contact transistors. This series extended from 2N21 to include more than 10,000 types, many of which are still in use today.
There are several serious collectors of early US transistors, in the USA of course. However I have been fortunate enough to accumulate a number of very early US types, even though I live in the UK. My image gallery shows these.