WWVH is the callsign of the U.S.

National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of p ...

shortwave Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (app ...

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

time signal A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day. Church bells or voices announcing hours of prayer gave way to automatically operated chimes on public clocks; however, au ...

station located at the Pacific Missile Range Facility Barking Sands, in Kekaha, on the island of

Kauai Kauai (), anglicized as Kauai ( or ), is one of the main Hawaiian Islands. It has an area of 562.3 square miles (1,456.4 km2), making it the fourth-largest of the islands and the 21st-largest island in the United States. Kauai lies 73 m ...

in the state of

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

. WWVH is the Pacific sister station to WWV, and has a similar broadcast format. Like WWV, WWVH's main function is the dissemination of the official U.S. Government time and frequency standard. Due to

ionospheric The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays ...

conditions, at certain times and locations some listeners may receive both WWV and WWVH on the same frequency at the same time. The information modulated on the carrier is modified to reduce confusion if both are received simultaneously. In particular, voice announcements on one correspond to silent periods on the other. WWVH uses a female voice (

Jane Barbe Jane Barbe ( ; July 29, 1928 – July 18, 2003) was an American voice actress and singer. She was known as the "Time Lady" for the recordings she made for the Bell System and other phone companies. The ubiquity of her recordings eventually made he ...

) to distinguish itself from WWV, which uses a male voice. WWVH time signals can also be accessed by telephone at +1 (808) 335-4363.

Transmission system

WWVH broadcasts its signal on four transmitters, one for each frequency. The 2.5 MHz transmitter puts out 5 kW, while the other transmitters provide 10 kW. The 2.5 MHz antenna is one quarter-

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

tall, and radiates in an omnidirectional pattern. The 10 and 15 MHz antennas are omnidirectional half-wave antennas. The 5 MHz antenna consists of two elements one half-wavelength tall and horizontally separated by one quarter-wavelength. This phased-array directional antenna produces a broad

cardioid In geometry, a cardioid () is a plane curve traced by a point on the perimeter of a circle that is rolling around a fixed circle of the same radius. It can also be defined as an epicycloid having a single cusp. It is also a type of sinusoidal ...

radiation pattern with a maximum gain directed west. Emergency stand-by transmitters and antennas are provided for each frequency.

Broadcast format

The WWVH signal is extremely similar to the WWV signal, but some changes have been made to reduce confusion if both are heard at once: * The 5 ms second ticks are 6 cycles of 1,200 Hz rather than 5 cycles of 1,000 Hz. The 800 ms minute beep is also 1,200 Hz. (Like WWV, this is omitted during minutes 29 and 59, and changed to 1,500 Hz at the top of each hour.) * The voice announcements use a female voice (that of

) and last 7.5 seconds starting 15 seconds before the minute. (WWV broadcasts in a male voice during the last 7.5 seconds of each minute.) * The audio tones sent during the first 45 seconds of most minutes are swapped: 600 Hz is played during even minutes, and 500 Hz is played during odd minutes. (Receiving both simultaneously gives the listener a sound similar to a continuously ringing chime.) * The

A440 A440 or A-440 may refer to: * A440 (pitch standard) * A440 highway (Australia), a road in Victoria, Australia * Quebec Autoroute 440 (Laval) * Quebec Autoroute 440 (Quebec City) See also * Apollo 440, an English band * Airbus A400M The Air ...

tone marking the hour is sent during minute 1 (as opposed to minute 2 for WWV). Like WWV, it is omitted during the first hour of each UTC day. * The audio tones are suppressed while WWV is transmitting voice announcements: minutes 00, 08–10, 14–19, and 30. * The voice announcements are rescheduled relative to WWV: ** Station identification is made during minutes 29 and 59 (vs. 00 and 30) ** GPS satellite health reports are transmitted during minutes 43 and 44 (vs. 14 and 15) **

NOAA The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with forecasting weather, monitoring oceanic and atmospheric conditions, charting the seas, conducting deep-sea exploratio ...

space weather geoalerts are transmitted during minute 45 (vs. 18) **

National Weather Service The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weathe ...

storm warnings for all sections of the Pacific Ocean are broadcast during minutes 48–51, overflowing to minute 52 when necessary (vs. Atlantic and northeast Pacific information during 08–10 and 11). ** Minutes 03 and 47 are used for NIST special announcements when necessary (vs. 04 and 16). Like WWV, prior to the

OMEGA Omega (, ; uppercase Ω, lowercase ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and last letter in the Greek alphabet. In the Greek numerals, Greek numeric system/isopsephy (gematria), it has a value ...

Navigation System shutdown in 1997, the OMEGA status report was broadcast at :47 past the hour.

Half-hourly station identification announcement

WWVH identifies itself twice each hour, at 29 and 59 minutes past the hour. The text of the identification is as follows: Reception reports sent to that address will on request be answered with a

QSL card QSL may refer to: *Q code The Q-code is a standardised collection of three-letter codes that each start with the letter "Q". It is an Operating signals, operating signal initially developed for commercial radiotelegraphy, radiotelegraph communi ...

Telephone service

WWVH's time signal can also be accessed by calling +1 (808) 335-4363.

References

External links

AT THE TONE: A Little History of NIST Radio Stations WWV & WWVH (1955-2005)
© 2009 Myke Dodge Weiskopf / Obscure-Disk. {{Authority control National Institute of Standards and Technology Kauai County, Hawaii Time in the United States Shortwave radio stations in the United States Time signal radio stations de:WWV (Zeitzeichensender)#Kurzwellensender WWVH auf Hawaii