[time-nuts] WWVB Response

[John Lowe]

Dear Time-Nuts Forum,

In an attempt to quiet the discussion that has started, I will take the 
unusual step and address this forum.

NIST is providing full disclosure of the WWVB PM format.  There are no 
hidden bits or protocols.  We will continue to be entirely forthcoming 
with the WWVB broadcast both in its content and its schedule.  All 
information is available and will continue to be available at:

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

NIST has never been in the business of developing, designing or 
producing receiver designs.  We provide the format and allow our users 
to create designs as they see fit.  Individuals are invited to design 
receivers based on the format provided.

We have taken great care to preserve the existing AM format of the WWVB 
transmission.  We expect the vast majority of AM envelope-type receivers 
will continue to operate as designed and will detect the Time-of-Day.  
Unfortunately, there are devices out there that detected the phase of 
the carrier through a Phase-Locked-Loop. These devices will no longer 
function as designed.  There are methods of creating an interface to 
recover the signal for these devices, some of which have been discussed 
and presented in this forum.  It is an unfortunate consequence of 
improving the reception capability of our broadcast that this segment of 
our loyal user base are so adversely affected.  The decision to proceed 
was not taken lightly, but in the end it was decided that the 
improvement in reception capability (especially along the JJY 
interference prone East Coast) outweighed the loss of use of existing 
PLL devices.

It should be noted that the carrier-phase information is still there and 
will provide the same level of reference calibration capability as it 
always has, it just must be extracted in a new way.  Maybe this change 
will prompt a commercial enterprise to develop a new WWVB frequency 
reference device as there has been no commercially produced frequency 
reference devices manufactured or supported in some time.

I have given much effort in being available to answer questions and 
provide information concerning this transition and I will continue to be 
available to help.  I hope this response to this forum aids in that effort.

Regards,

John Lowe
WWVB Broadcast Manager
NIST Time and Frequency Division