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Enhanced WWVB Broadcast Format Change

Since October 29, 2012 at 1500 UTC (9:00 AM MDT), NIST Radio Station WWVB has been broadcasting a phase modulation (PM) time code protocol that has been added to the legacy AM/pulse-width-modulation signal. This enhancement to the broadcast, which has been tested throughout 2012, provides significantly improved performance in new products that are designed to receive it. Existing radio-controlled clocks and watches are not affected by this enhancement, and continue to work as before. A detailed technical description of the new format can be found here.

Disciplined oscillator products that track and lock to the 60 kHz WWVB carrier and were designed to work as frequency standards, will not work with the PM signal and will now become obsolete. A few radio controlled clocks that used information from the carrier – specifically the Spectracom NetClock and receivers manufactured by True Time during the 1970s and 1980s – will no longer be able to read the time code and will also be obsolete. For more information, contact Broadcast Manager John Lowe at john.lowe@nist.gov or 303-497-5453.

Broadcast Outages for WWVB


 WWVB Home 2003 Outages2004 Outages 2005 Outages2006 Outages 2007 Outages2008 Outages 2009 Outages

2010 Outages 2011 Outages 2012 Outages 2013 Outages 2014 Outages2015 Outages2016 Outages2017 Outages

During normal operation, the 60 kHz signal from WWVB is transmitted 24 hours per day, 7 days a week. The table includes periods when the signal was off or intermittent for more than 5 minutes.

Date MJD Began (UTC) Ended (UTC)
21 December 20145701219462042
30 November 20145699106510745
14 October 20145694407080824
13 October 20145694302380328
3 October 20145693300290119
20 September 20145692005490639
13 September 20145691321172206
22 August 20145689100570125
21 August 20145689010101119
27 July 201456865

---

0021
26 July 2014568642236

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25 July 20145686306530811
8 July 20145684601580248
3 July 20145684100230140
4 June 20145681211471233
12 May 20145678922342252
11 May 20145678814501603
10 May 20145678704420530
31 March 20145674709221042
15 March 20145673114431547
11 February 20145669923272337
09 February 20145669719062006
06 February 20145669406380745
12 January 20145666919181956
12 January 20145666911151223
10 January 20145666708180918
09 January 20145666610371152

04 January 2014

56661

0707

0801