WWVH

WWVH is a shortwave time signal station operated by the National Institute of Standards and Technology (NIST) in the United States. It serves as the Hawaiian counterpart to WWV, supplying precise Coordinated Universal Time (UTC) time signals to the public, maritime and aviation communities, researchers, and radio enthusiasts. Like WWV, WWVH provides continuous timekeeping information and standard time announcements to aid in calibrations and navigation across the Pacific region.

Transmission: WWVH broadcasts on a set of standard shortwave frequencies, including 2.5, 5, 10, 15, 20, and 25 MHz, and uses a one-second time pulse to encode the current UTC. The station also delivers periodic spoken time announcements and date information, designed to be understood even when the data signal is not decoded. The time code is synchronized to the NIST time scale, with leap seconds announced by the IERS.

Voice and style: The spoken announcements at the top of the minute are delivered by a female announcer, distinguishing WWVH from its mainland counterpart. The broadcasts also include standard UTC time, date, and station identification, aiding listeners who rely on audible time checks.

History and role: WWVH has operated as a companion to WWV since the mid-20th century to support timekeeping, navigation, and radio synchronization across the Pacific. It is part of NIST's time and frequency services and continues to serve researchers, hobbyists, and professional users who rely on accurate time signals.