From FB group Building Transistor Radios
The silicon transistor wafers may have been made in the US, but the wafers were shipped to foreign countries to be assembled into the actual transistors. The wafer is cut up into tens of thousands of individual transistors, and after assembly they are tested and separated by the results. All the transistors that meet certain specifications might be labeled as 2N3904, a number registered in the US. Or the same transistor might be wired differently inside, and then labeled as a BC547, which is a number in the Pro Electron series, which is used by European countries. Or it was connected another way inside, and then labeled as 2SC945, which is a number registered in Japan. Or some large company might order a hundred thousand of a particular transistor and have them labeled with a house number that was assigned by the company in their specification sheet.
The point is that the transistors aren’t American or Japanese, they were labeled that way by some foreign company, which might be in Hong Kong, Taiwan, or China.
