Radio Station WWVH 15 MHz

Radio Station WWVH

NIST radio station WWVH broadcasts time and frequency information 24 hours per day, 7 days per week to listeners worldwide. The station is located on the Island of Kauai, Hawaii on a 12 hectare (30 acre) site near Kekaha at Kokole Point. The information broadcast by WWVH includes time announcements, standard time intervals, standard frequencies, UT1 time corrections, a BCD time code and geophysical alerts.

Broadcast Frequencies

WWVH operates in the high frequency (HF) portion of the radio spectrum and radiates 10 000 W on 10 MHz and 15 MHz, and 5000 W on 2.5 MHz. Notice: the 5 MHz broadcast which normally radiates 10 000 W is currently operating at 5000 W due to equipment failure.

Each frequency is broadcast from a separate transmitter. Although each frequency carries the same information, multiple frequencies are used because the quality of HF reception depends on many factors such as location, time of year, time of day, the frequency being used, and atmospheric and ionospheric propagation conditions. The variety of frequencies makes it likely that at least one frequency will be usable at all times.

Antennas

From 2000 to 2007, NIST has installed new antennas encased in fiberglass rather than traditional steel supports, to resist corrosion from the salty ocean air. The fiberglass design will reduce maintenance and repair costs. The new design also enables the flexible, lightweight antennas to be easily lowered to the ground for maintenance, reducing safety hazards to staff. The improved antennas should reduce signal downtime for WWVH users. The 5 MHz antenna system consists of half-wave phased array vertical antennas. The 2.5 MHz, 10 MHz and 15 MHz antennas are base-fed vertical monopoles that radiate omnidirectional patterns. Each frequency also has a vertical monopole standby antenna connected to the standby transmitters, in the event that the primary system fails.

WWVH Antenna Coordinates

Frequency (MHz)	Latitude	Longitude
2.5	21° 59' 20.9" N	159° 45' 52.4" W
5	21° 59' 10.8" N	159° 45' 44.8" W
10	21° 59' 18.2" N	159° 45' 51.3" W
15	21° 59' 15.3" N	159° 45' 50.0" W

Modulation

The signals broadcast by WWVH use double sideband amplitude modulation. The modulation level is 50 percent for the steady tones, 50 percent for the BCD time code, 100 percent for the second pulses and the minute and hour markers, and 75 percent for the voice announcements.

Other Information about WWV and WWVH

• NIST Time and Frequency Services (NIST Special Publication 432): A detailed 80 page overview of NIST time and frequency services and how to use them. Chapter 3 is all about WWV and WWVH.

• Frequently Asked Questions

• Manufacturers of Time and Frequency Receivers: Links to manufacturers of WWV/WWVH and other time and frequency receivers

Questions? Send mail to: wwvh@boulder.nist.gov

Informazioni da: https://www.nist.gov/pml/time-and-frequency-division/time-distribution/radio-station-wwvh

 

Il 29 marzo 2023 dalle 05.25 alle 05.31 UTC sulla frequenza 15000 kHz in modalità AM, SINPO 3 4 3 3 3.

Ho ricevuto dal sito trasmittente sull’isola di Kauai, Hawaii – U.S.A., “15 MHz WWVH Broadcast”, il segnale era sufficiente, con presenza di molto rumore di fondo.

 La stazione radio WWVH è a circa 12394 km dal mio QTH

Setup di ascolto: ricevitore SDRplay RSPdx, software SDRuno, antenna 14.5 m Terminate Folded Dipole (T2FD) installata inverted vee (homebuilt)

Rapporto d'ascolto inviato all'indirizzo email: wwvh@boulder.nist.gov, conferma con lettera contenente folder informativo e  QSL dopo 14 gg.

 AUDIO MP3