[The dedicated amateur].

This is the text of an inauguration lecture at Umeå Universitiy (a chair of the history of science and ideas). The lecture is based on a study of magazines like Populär Teknik (Popular Technology), popular science literature, handbooks for mechanical and electrical experimentation, mail-order catalogs etc. from 1920-50, and its theme is that amateurs and hobbyists interested in popular science, technology and "do-it-yourself" have played an important role in modern society. Here we find a world exclusively occupied by boys and men, where it is made a virtue of playing with technological toys, and where mechanical and electrical tinkering becomes a significant part of the construction of masculinity. But the activities of amateurs and hoppyists can also be seen as an important way of self-education where the boy may get in touch with the scientific and technological frontier of the time, and there are many examples (e.g. in early history of radio or personal computers) where amateurs invented and developed new technology. The spirit of amateurs and hobbyists can even contain elements of a modern civic ideal: don't become dependent upon professional experts, don't trust authorities or big business that want to control technology, trust yourself and your knowledge. In short: do it yourself.