(Source: Washington Post via Ulis K3LU)
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.
Depending on where you are in the United States, those frequencies will bring you to WWV and WWVH, two extremely accurate time signal stations.
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.[…]
If you’d like to hear why I believe WWV/WWVH and WWVB are important services, check out this interview I did with Scott Simon for NPR Weekend Edition.