Transistor radio
radio receiver that uses semiconductor active elements
A Transistor radio is a radio receiver which uses transistors to amplify the sound. Transistor radios can be cheap and small and some use very little electric power. Some can amplify the weak radio waves that are usually not picked up by weaker vacuum tube radios. Transistor radio broadcasting receivers for portable use were sold in great numbers starting in the late 1950s. Soon, vacuum tube radios became rare.
Wikimedia Commons has media related to Transistor radios.