The transistor radio was invented in 1947. It allowed people to carry radios with them.

Transistor radio - Wikipedia

The Transistor Radio Launches the Portable Electronic Age, At the Smithsonian

Why the radio is one of history's most important inventions

It's Sixty Years Since the First Portable Transistor Radio Went on the Market and Started a Revolution

Transistor - Wikipedia

Transistor Radio

The transistor: 75 years since the famed Nokia Bell Labs invention changed the world - Nokia Bell Labs

The Transistor Radio Nuts & Volts Magazine

The transistor revolution: how transistors changed the world

Who invented the first portable radio? What were they used for? - Quora

Old portable radios were marvels of technology from the 1950s to the 1980s - Click Americana

Let's Get Small SPARK Museum of Electrical Invention

Invention of radio - Wikipedia

Who Invented the Transistor Radio? Discover the Origins

The Transistor Radio Nuts & Volts Magazine