[time-nuts] WWVB d-psk-r down conversion method...

Brooke Clarke brooke at pacific.net
Tue Sep 23 18:11:23 EDT 2014

Hi Alex:

There's not a requirement that Xtgendwave make the chip.  The modulation format is published by NIST and anyone can make 
a receiver.
I would hope there's some Time Nuts that would be interested in doing this rather than trying to remove the phase 

It's my understanding that by using the fast (100 bits/second - 10 second frame time) signal  you can get more precision 
than possible using the old WWVB signal.

Note:  The Xtgendwave patents spend a lot of time and effort compensating for the poor quality of the watch crystal.  If 
it's in spec but not exactly on frequency, then decoding a signal that's 17 minutes long is a big problem.  For time 
nuts use where we have a precision LO all that goes away and instead we could be looking at how to get  more precision 
and at the same time more updates.

Have Fun,

Brooke Clarke

Alexander Pummer wrote:
> Hi Brooke,
> I hope that you are right with that chip, and despite the name change of the company -- now Xtendwave -- and 
> recovering  they will deliver something some times. I can see that with correlation and averaging schemes the signal 
> to noise ratio of data, perhaps constant frequency could be improved, but I would be very interested to see of the 
> mathematical model of improving the signal to noise ratio of timing.
> Regards
> Alex
> On 9/23/2014 1:08 PM, Brooke Clarke wrote:
>> Hi Alex:
>> Sometime in the future there will be chips that will decode the new signals (note the "s" on the end of that last 
>> word).  There are a number of frame times the longest one of which takes 17 minutes and is transmitted only once per 
>> day.  This format offers 23 dB modulation gain compared to the 1 minute time frame transmission that the current 
>> clocks use.  There are a total of 5 different modulation formats that will be transmitted over different time 
>> frames.  In the end everyone should have a clock with more frequent updates (on the West coast I might need to wait 
>> overnight for a clock to sync after a battery change) and more accuracy.
>> http://prc68.com/I/Loop.shtml#PhaseMod
>> Have Fun,
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