Transistor radio

Portable radio receiver

A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Previous portable radios used vacuum tubes, which were bulky, fragile, had a limited lifetime, consumed excessive power and required large, heavy batteries. Following the invention of the transistor in 1947—a semiconductor device that amplifies and acts as an electronic switch, which revolutionized the field of consumer electronics by introducing small but powerful, convenient hand-held devices—the Regency TR-1 was released in 1954 becoming the first commercial transistor radio.

From Wikipedia, under CC BY-SA. More on occurri.