[Elecraft] OT: Changes at WWV, WWVB

[Tom Blahovici]

Hi interesting. It appears all Citizen atomic watches purchased recently use the newer protocol. Mine syncs every night even in a drawer and maintains the time to 1/4 of a second a day. 
How in the world does such a small antenna work at 60 kHz?

On Nov 28, 2014 3:18 PM, Ken G Kopp <kengkopp at gmail.com> wrote:
>
> I have a long-time close friend who's retired from 
> the NBS in Boulder and was the project engineer 
> on the NBS #7 cesium standard.  After the recent 
> reflector postings about  WWV / WWVB I thought 
> I would get first-hand recent information from him. 
>
> The GPS satellites all carry on-board cesium 
> standards that are synchronized with NTIS, and 
> because of changes (below) to WWVB, cell phones 
> remain the most accurate source of time for most of us. 
>
> All the HF transmitters at Ft. Collins are the same TMC 
> units that were put in service when the facility was built. 
> The 2.5 and 20 MHz transmitters run at lower power due 
> to propagation considerations. 
>
> The time and other station-related voice info is sourced 
> on site in Ft. Collins, and the various propagation and 
> weather info comes from various "dial in" land-line 
> sources. Hence the widely varying quality of these 
> announcements.  I forgot to ask about the individual 
> who made the voice recordings ... 
>
> Here's the most important info .... as of about a year 
> ago the modulation scheme on WWVB (60 kHz) was 
> changed (phase reversal each minute) and this has 
> rendered most of the end-user equipment inoperative. 
> Most (all ?) tracking receivers like the HP-117's are 
> now useless without extensive modification. 
>
> Most of the "atomic" clocks now in use ->do not<- synch 
> to the current modulation scheme on the 60 kHz signal. 
> This will explain the differences in displayed time on 
> supposedly identical clocks and how some appear to 
> not be getting sufficient enough signal to synchronize. 
>
> He offered no comment on how to locate "consumer" 
> clocks that -do- respond to the "new" modulation scheme. 
>
> The 60 kHz transmitter is indeed an ex-LORAN C unit, 
> and because of the higher power of the "new" transmitter 
> the antenna system was rebuilt using material from the 
> LORAN C site. 
>
> The 20 kHz transmitter was "home made" by NBS staff 
> at the old Beltsville, MD facility and moved to Ft. Collins. 
> There is no longer an antenna for this transmitter and it 
> will not return to the air.  Trivia:  The antenna was of 
> such high-Q that a near-by thunderstorm system would 
> often detune the system and cause the overload protection 
> to trip the transmitter off. 
>
> He suggests that a visit to the NBS website would be 
> "informative". 
>
> 73 
>
> Ken Kopp - K0PP 
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