WWVB

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. WWVB is a NIST time signal radio station near Fort Collins, Colorado, co-located with WWV. WWVB is the station that radio-controlled clocks throughout North America use to synchronize themselves. The signal transmitted from WWVB is a continuous 60 kHz carrier wave, derived from a set of atomic clocks located at the transmitter site. A 1 bit-per-second time code, which is based on the IRIG "H" format of time code and derived from the same set of atomic clocks, is then modulated onto the carrier wave using a technique described as pulse width modulation followed by amplitude-shift keying. The time in this code is given in UTC, which the radio-controlled clocks then have to convert to their own local time. A single complete frame of time code lasts one minute.