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From time to time I like to review various products that are of interest to hams, as well as to others. This time I am going to look at a neat little high-performance WWV/WWVH receiver. You can build it yourself or buy it wired and tested.
But first, some background "for those who came in late."
WWV BASICS
The National Institute of Standards and Technology (NIST), successor to the old National Bureau of Standards, operates several time and frequency standards stations. There are two HF shortwave stations (WWV at Fort Collins, Colorado, and WWVH at Maui, Hawaii), and one 60-kHz VLF station (WWVB, Fort Collins). Both HF stations operate on 2.5, 5, 10, and 15 MHz (WWV also transmits on 20 MHz). You can tell the difference between them by the announcer: WWV uses a male voice and WWVH uses a female voice. On occasion, you can hear both at the same time, but for the most part only one will be audible at any one listening site.
These stations offer a number of different services. The NIST WWV Web site is www.boulder.nist.gov/ timefreq/wwv. The site has a couple of .QuickTime video movies that explain what the organization does for the public. In brief, the services include: time announcements, standard time intervals, standard frequencies, UT1 time corrections, and BCD time code (which can be used for WWV-controlled time clocks).
Further, NIST broadcasts geophysical alerts, prepared by the Space Environment Services Center of NOAA. These are aired on the 18th minute of the hour to give information on solar activity, geomagnetic fields, solar flares and other geophysical statistics. More Earth-based alerts are given by NIST, too, such as marine storm warnings (prepared by the National Weather Service).
OMEGA Navigation (10-14 kHz) System status reports are also handled, as well as Global Positioning System (GPS) status reports (prepared by the U.S. Coast Guard to give current status information to mariners on the GPS navigation satellites).
The WWV and WWVH output frequencies are useful for secondary frequency measurements and calibration in your ham shack. For example, hams often calibrate 100- and 1000-kHz crystal-marker oscillators to either WWV or WWVH. The time announcements and BCD code are related to the NIST atomic time scales in Boulder, Colorado.
The...