The transistor was the first electronic amplifying device, capable of substituting De Forest's Vacuum tube with equivalent or superior performance and definitely smaller in size.

It was developed in the Bell Labs, the famous laboratories of the American telephone company, in 1947-48. In 1954-55, while the transistor was being tested in the field of computer science, still limited to few pioneers, the American company Texas Instruments was experimenting, and then marketed, a new use for the product which proved to be much more for the “masses”: a transistor radio charged by batteries, decisively smaller and lighter (less than 1/2 a kilo) than the portable radios available at the time.

Also in 1954, the physicist Edwin Armstrong, inventor of frequency modulation radio, committed suicide because he was convinced that his invention would not have been applicable commercially due to the opposition of the big companies in the sector. In the years that followed, frequency modulation did affirm itself thanks as well to the diffusion of portable radios.