How do radio clocks work? History? Price?

The electric wave watch is the fifth generation of timepieces after hourglass, sundial, mechanical clock and quartz clock in the development of human timekeeping. It combines the traditional clock technology with high-tech time and frequency and electronic technology, and receives the standard time signal transmitted by the national time signaling center by radio long-wave, and after the built-in microprocessor decodes and processes it, it automatically calibrates the timer to keep the time, so that the time displayed on the electric wave watch is synchronized with the standard time kept by the state automatically and accurately. The most famous radio wave watch should be Casio and Citizen.