If you tune a shortwave radio to 2.5, 5, 10 or 15 MHz, you can hear a little part of radio history — and the output of some of the most accurate time devices on Earth.
Developed before commercial radio existed, WWV recently celebrated its 100th anniversary. It’s the oldest continually operating radio station in the United States.
Both stations are overseen by the National Institute of Standards and Technology, the federal agency that governs standards for weights and measures and helps define the world’s official time.
That time can be heard on shortwave radio 24/7.
Early on, WWV focused on experimental broadcasts (think Victrola concerts that wowed early radio users). Beginning in…
