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| Station: |
| WWVB |
| Frequency: |
| 60 kHz |
| Transmitting
power: |
| 50 kW |
| Location: |
| Fort Collins / Colorado |
| Receiving
area: |
| 2000 km |
| Geographical
coordinates: |
| 40° 40' N, 105° 03' W |
| Time
of transmission: |
| permanent |
| Modulation: |
| 69% |
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Time code information according the NIST document
The information is present as a continuous bit stream with a data rate
of 1 bit per second by using pulse width modulation.
The power of the carrier is reduced 10dB at the beginning of each second
and then restored to its full level. Thus, the leading edge of every negative
going pulse is on time.
Coming back to full power after 0.2 seconds represents a binary "0",
after 0.5 seconds a binary "1". A position marker (P0 to P5)
is signalised by a 0.8 second delay. The binary coded decimal (BCD code)
format is used to combine binary digits in order to represent decimal
numbers (for location of the information, as well as content) see drawing).
This gives the possibility to decode all necessary information of time,
day of the year and year (and some additional information as flags for
leap year and leap seconds) out of the signal.
Please verify this information before commercial use !
http://www.bldrdoc.gov/timefreq/stations/wwvb.htm
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