WWV (radio station)

For other uses, see WWV (disambiguation).
WWV Transmitter Building (2002 or earlier)
WWV's 15 MHz antenna

WWV is a shortwave ("high frequency" or HF) radio station, located near Fort Collins, Colorado. It has broadcast a continuous time signal since 1945, and implements United States government frequency standards, with transmitters operating on 2.5, 5, 10, 15, and 20 MHz.[1] WWV is operated by the U.S. National Institute of Standards and Technology (NIST), under the oversight of its Time and Frequency Division, which is part of NIST's Physical Measurement Laboratory based in Gaithersburg, Maryland.[2]

WWV was established in 1919 by the Bureau of Standards in Washington, D.C., making it one of the oldest continuously-operating radio stations in the United States.[3] NIST celebrated WWV's centennial on October 1, 2019.[4]

In 1931, the station relocated to the first of three suburban Maryland sites, before moving to a location near Fort Collins in 1966. WWV shares this site with longwave (also known as "low frequency" or LF) station WWVB, which transmits carrier and time code (no voice) at 60 kHz. NIST also operates shortwave station WWVH on Kauai, Hawaii. Both WWV and WWVH announce the time of day each minute in Coordinated Universal Time, and make other recorded announcements of general interest on an hourly schedule, including the Global Positioning System (GPS) satellite constellation status. Because they simultaneously transmit on the same frequencies, WWV uses a male voice in order to differentiate itself from WWVH, which uses a female voice.

  1. ^ Experimental transmissions at 25 MHz were last conducted in 2014. They were discontinued due to solar flux levels dropping below that needed for propagation at upper HF/shortwave frequencies. This deterioration began in the latter years of the 24th Solar cycle.
  2. ^ "Physical Measurement Laboratory: Time and Frequency Division". NIST. NIST.gov. 2 July 2009. Retrieved 22 December 2018.
  3. ^ "What Closing A Government Radio Station Would Mean For Your Clocks" (transcript), Weekend Edition Saturday, August 25, 2018 (NPR.com)
  4. ^ "NIST Radio Station WWV 100-year Anniversary" (NIST.gov)