[time-nuts] ANN: UK MSF 60 kHz interruption, 2012 June 14

[paul swed]

As noted above the propagation can make quite a mess of things.
When wwvb launched way back there was a HP journal showing that in NY city
you could establish something like 1 X 10-7th as I recall.
I have seen all the propagation twists and turns.
I suppose if you were 300-400 miles from the transmitter and could receive
groundwave signals you might do 10 X better or more.
Regards
Paul.

On Mon, Jun 4, 2012 at 3:35 AM, mike cook <michael.cook at sfr.fr> wrote:

>
> Le 4 juin 2012 à 05:43, David I. Emery a écrit :
>
> > On Sun, Jun 03, 2012 at 09:20:59AM -0700, J. Forster wrote:
> >> Is there any indication the carriers of WWVB and MSF are locked
> together?
> >>
> >> -John
> >>
> >> =================
> >
> >       Given it's only 60 KHz and certainly somewhere north of parts in
> > 10^13 and probably  down to 10^14 or 10^15 the distinction kinda escapes
> > one.
> >
> >       They may not be locked to each other, but are so close in
> > frequency that relative drift would be AWFULLY slow... especially if its
> > more like 10^15 from primary maser standards...
> >
> >       There are only 5.184 * 10^9 cycles of 60 KHz  in a day after
> > all... and it takes a while for a error of a few parts in 10^15 to
> > pile up to one whole cycle...
> >
>
> From the doc on NIST and NPL sites, we are not in maser country here. The
> transmitters frequencies are disciplined by cesium standards.  For WWVB the
> frequency is kept to a few parts in 10^13 ( NIST Special Publication 423)
> and for MSF at 2 parts in 10^12 and are both sync'd to UTC(k).  As tvb
> points out, the the received signal will be phase shifted according to TOD
> and atmospheric conditions. The guys at NPL monitor(ed) the MSF signal to
> provide(ed) data for anyone wanting to use it for calibration in monthly
> bulletins of performance. I expect NIST do the same for WWVB but have been
> able to find a ref. Check out <
> http://npl.co.uk/upload/pdf/user_guide_bullitins.pdf> and the last
> bulletin that the site links point to , for april 2011, <
> http://resource.npl.co.uk/time/bulletins/msf/msfbul_04_2011.pdf>. What is
> interesting from the MSF data is that the phase offsets are quite
> significant where they are received in what I expect are optimal conditions
> at midday when ionospheric effects are minimal.  I don't know what happened
> to latter issues if any.   Did they abandon them?
>
> >
>
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