[time-nuts] WWVB paper in May 2014 IEEE communications...

Steven Kluck stevekluck at gmail.com
Sat May 31 17:11:49 EDT 2014


I have been able to consistently receive the WWVB phase-modulated data of
what is now being referred to as "Normal Mode" since last summer, using an
air-wound coil antenna, multiple op-amp front end, and a PIC
microcontroller setup that I originally used for receiving the
amplitude-modulated signal.

I think that Bob Camp brings up a legitimate issue when he writes "I kind
of doubt that the watch and clock guys are going to start the fabs turning
out millions of chips until they can test all the formats."

One observation has been that data interpretation does not look altogether
simple.  With the AM scheme, you could easily find the beginning of a
minute frame, just by looking for two consecutive markers. With the PSK
Normal Mode, each second begins with a 13-bit sync word.  Sounds simple
enough, but if you see the sync word pattern, don't jump to any
conclusions, because the pattern will re-occur sometimes at other places
within the same minute frame.  It strikes me that when product testers
develop test cases, their work is complicated by all of these "special
cases" some of which will not actually occur until decades from now.

I also wonder if the introduction of new products has been delayed because
of the seemingly capricious manner in which changes are made to the
broadcast specification.  Normally, if portions of a communications
protocol are To Be Determined, we see early versions of specifications
which formally reserve certain areas or aspects that are subject to change,
so that early designers can nonetheless work around them. Who wants to put
a trademark on a product that suddenly ceases to operate when the next
unpredictable format change occurs? (Can you tell that I might be a little
frustrated?)

I've noticed that instrument manufacturers typically have quality programs
that are useful in establishing the reliability of their products. Such
manufacturers may run into a traceability problem in that the NIST's
coverage by quality programs apparently doesn't currently extend to the
Time and Frequency Division.  --Steve





On Sat, May 31, 2014 at 8:01 AM, Bob Camp <kb8tq at n1k.org> wrote:

> Hi
>
> Well that’s a bit more information. We seem to be missing the deployment
> schedule on the other new modulation formats. I kind of doubt that the
> watch and clock guys are going to start the fabs turning out millions of
> chips until they can test all the formats.
>
> …… the 100 bps signals looks interesting …. Not real clear how well it
> will do with a <30Hz wide crystal filter.
>
> Bob
>
>
> On May 31, 2014, at 4:14 AM, Tom Van Baak (lab) <tvb at leapsecond.com>
> wrote:
>
> > http://tf.boulder.nist.gov/general/pdf/2719.pdf
> >
> > /tvb (i5s)
> >
> >> On May 31, 2014, at 1:03 AM, "David I. Emery" <die at dieconsulting.com>
> wrote:
> >>
> >>   Well the actual details of the WWVB modulation and time
> >> codes are now published.
> >>
> >>   Was just leafing through some journals while doing some
> >> boring system configuration here...
> >>
> >>   IEEE Communications Magazine May 2014 has a paper on page 210
> >> by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe
> >>
> >> "WWVB Time Signal Broadcast Format and Multi Mode Receiver"
> >>
> >>   Seems to tell a lot more...
> >>
> >> --
> >> Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston,
> Mass 02493
> >> "An empty zombie mind with a forlorn barely readable weatherbeaten
> >> 'For Rent' sign still vainly flapping outside on the weed encrusted
> pole - in
> >> celebration of what could have been, but wasn't and is not to be now
> either."
> >>
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at febo.com
> >> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



More information about the time-nuts mailing list