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
|
|
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) |
|
04-06-2013
|
56388
|
1215
|
1315
|
| 03-16-2013 |
56357 |
0906 |
1012 |
|
12-09-2012
11-22-2012
|
56270
56253
|
0323
2315
|
0400
0005
|
|
10-08-2012
10-02-2012
|
56208
56202
|
2104
0403
|
2216
0453
|
|
09-23-2012
09-18-2012
|
56193
56188
|
1744
0754
|
1848
0856
|
|
08-19-2012
08-04-2012
06-25-2012
06-11-2012
|
56158
56143
56103
56089
|
1222
1315
0336
0623
|
1328
1423
0436
0736
|
| 05-19-2012 |
56066 |
1106 |
1220 |
| 05-16-2012 |
56063 |
0218 |
0310 |
| 04-28-2012 |
56045 |
2255 |
2354 |
| 04-24-2012 |
56041 |
0717 |
0818 |
| 04-15-2012 |
56032 |
0100 |
0130 |
| 04-09-2012 |
56026 |
2310 |
2346 |
| 03-08-2012 |
55994 |
0845 |
0948 |
| 02-28-2012 |
55985 |
2059 |
2120 |
| 02-23-2012 |
55980 |
0026 |
0107 |
| 02-22-2012 |
55979 |
0712 |
0809 |
| 01-28-2012 |
55954 |
2237 |
2331 |
| 01-26-2012 |
55952 |
1115 |
1243 |
| 01-25-2012 |
55951 |
0725 |
0735 |
| 01-25-2012 |
55951 |
0625 |
0635 |
| 01-24-2012 |
55950 |
0725 |
0735 |
| 01-24-2012 |
55950 |
0625 |
0635 |
| 01-23-2012 |
55949 |
0725 |
0735 |
| 01-23-2012 |
55949 |
0625 |
0635 |
| 01-20-2012 |
55946 |
0725 |
0735 |
| 01-20-2012 |
55946 |
0625 |
0635 |
| 01-15-2012 |
55941 |
2204 |
2322 |
| |
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
