[EAS] Alerting options

[Tom Spencer]

Cross, Robin wrote:
> An what about including WWVB in the EAS structure???

No good way to do that - but there's nothing that says they couldn't 
build another VLF station on, say 110 kHz, with 100 kW ERP...

WWVB's inputs are directly from the NIST Master Clock. Not sure exactly 
what "The B"s emission designator is, actually... 1H0D2D?

http://www.nist.gov/pml/div688/grp40/wwvbtimecode.cfm

And it's sort-of AM, but with no audio...

http://www.nist.gov/pml/div688/grp40/wwvb.cfm

There are no voice announcements on the station, but a time code is 
synchronized with the 60 kHz carrier and is broadcast continuously at a 
rate of 1 bit per second using pulse width modulation. The carrier power 
is reduced and restored to produce the time code bits. The carrier power 
is reduced by 17 dB at the start of each second, so that the leading 
edge of every negative going pulse is on time. Full power is restored 
0.2 s later for a binary "0", 0.5 s later for a binary "1", or 0.8 s 
later to convey a position marker. The binary coded decimal (BCD) format 
is used so that binary digits are combined to represent decimal numbers.

endquote

But ordinary AFSK would do for WEAS-LW.

-- 
Tom Spencer