What are the differences between old and modern radios?

The earliest radiOS were based on vacuum tubes. In the 1950's, vacuum tubes gradually became replaced by transistors, to produce what were known as solid state radiOS (solid because they did not contain any vacuum). Since then, there have been many other refinements. At one time, you could only tune to a specific frequency by turning a knob until you manually located it; now we have systems that can find frequencies automatically, and can return to them automatically at the press of a button. Every aspect of a radio has been refined by decades of research and development. We also now have satellite radio, in addition to regular kinds of broadcast, which is another major development.