[NLRS] Link -- New phase-modulation WWVB signal

[Dr. Gerald N. Johnson]

There could easily be local QRM like a switching supply that's slightly 
temperature sensitive, a NTSC TV display with the new digital horizontal 
warped to 15.00 instead of 15.75 under some digital converter scheme. 
That switching supply could be in any appliance, any CFL, any electronic 
lamp ballast, or any LED supply or a combination of all of the above in 
the neighborhood, not just the house.

I'm sure NIST has incomplete knowledge of how the existing receivers 
work and it seems to me that with the low cost and microscopic antennas 
used, that the receiver has to be a phase locked synchronous receiver to 
detect the amplitude shifts that have been used for decades and adding 
phase shifts may be beyond the receiver's tolerance. But it should 
correct in the half hour intervals not yet phase encoded if the signal 
was usable. Since PSK requires the least S/N of all known signaling 
schemes the new receivers should do better on rotten and QRM'd signals. 
If their own monitor is showing poor or undetectable signal, there might 
be an indication that there are problems at Ft. Collins they need to 
work on someday when they have a budget again.
whether they have the new style receiver or not? Its not like they plan 
to sell only to users with technical knowledge so they may tend to 
neglect to mention that until they can detect a serious improvement in 
performance.

73, Jerry, K0CQ

On 3/13/2013 7:15 AM, Duane - N9DG wrote:
>
>
>
> According to the NIST website they have be transmitting this way since Oct 29, 2012. And they have been including two 30 minute periods per day where the PM modulation was turned off. Those 1/2 hour periods are due to end on March 21.
>
> http://www.nist.gov/pml/div688/grp40/wwvb.cfm
>
> Duane
> N9DG
>
>
>
>