WWV HF transmissions include a 100 Hz subcarrier that gives the info in cw format.

For generating WWVB code I would suggest simply counting seconds to yield days -- the WWVB code takes the day number in the year.  Leap year is easy.  Just look up the DST start and stop.

acb

From: time-nuts time-nuts-bounces@lists.febo.com on behalf of paul swed paulswedb@gmail.com
Sent: Sunday, August 12, 2018 1:47 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] NIST

Well if the old LF and HF signals go away I am on for yet another wwvb
project and wwv. What the heck.
Creating a AM wwvb is really pretty easy and in fact I have done that.
Can't remember what code that was.
Pretty sure it was basic on SXb2. But the good news is the old BPSK code
isn't needed so it really becomes easy.
The BPSK coder was seriously complicated. (That was the cheatin dePSKr)
So it would be GPS to WWVB code. Have to think about the DST thing. Thats
always a bit messy.

Lastly while I am at it there would be a 5 and 10 MHz wwv simulator at
least ticks and minute tone. Looked at voice and thats a bit of a mess.
They seem to just say numbers. Not sure there are modules that say time
from my bit of research.
Of course have to be careful with transmission levels.... Looks like its
time yo look up fcc part 97.

Things to ponder.
Regards
Paul
WB8TSL

On Sun, Aug 12, 2018 at 4:19 PM, Wes wes@triconet.org wrote:

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and follow the instructions there.

How exactly does one get submillisecond time of day precision with a
sextant?
(even if sticks and pebbles are thrown into the mix)
I'd say more like ~1 sec precision on a really fine day, it the sextant is
wielded by
a skilled and practiced operator who has apriori knowledge of his location.

And what about standard frequency dissemination?

I'm also upset about the notion of time distribution and transfer by
internet.  Now
there's a fine example of a system that could be brought down by a single
competent
hacker!

And all it takes is one really good solar flare to bring down GPS (and
Glonass and
the others) semipermanently, if the reports I read are true.

I argue that instead of shutting down distribution avenues, NIST should be
making
additional ones available.

A lot has been said lately about how rapidly our technology is exploding.
But think
about how much of that is critically dependent on precision time transfer
over the
planet, and how much longer it would take mankind to recover from (insert
your favorite
disaster here) without good time and frequency transfer still up and
working.

Dana

On Sun, Aug 12, 2018 at 2:06 PM, djl djl@montana.com wrote:

Hi

Well…. there’s also the solar flare that vaporizes the planet earth :)

A flare big enough to take out all the sat systems would disrupt a lot more than just navigation.
It also probably is big enough to take out HF radio gear as well. It takes a lot of energy to
permanently take out a sat system. Hour or two disruptions … sure … total destruction, that’s
getting into crazy levels.

Bob

A good sextant with a good operator can measure apparent altitude to 0.1 minutes of arc.  The fastest apparent motion of objects in the sky due to rotation of the earth is 0.25 minutes of arc per second.  So the best a sextant can do with time (assuming accurate astronomical tables and an exact knowledge of position) is 0.4 seconds of time.

acb

From: time-nuts time-nuts-bounces@lists.febo.com on behalf of Dana Whitlow k8yumdoober@gmail.com
Sent: Sunday, August 12, 2018 4:29 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bicentennial GOES satellite clock

How exactly does one get submillisecond time of day precision with a
sextant?
(even if sticks and pebbles are thrown into the mix)
I'd say more like ~1 sec precision on a really fine day, it the sextant is
wielded by
a skilled and practiced operator who has apriori knowledge of his location.

And what about standard frequency dissemination?

I'm also upset about the notion of time distribution and transfer by
internet.  Now
there's a fine example of a system that could be brought down by a single
competent
hacker!

And all it takes is one really good solar flare to bring down GPS (and
Glonass and
the others) semipermanently, if the reports I read are true.

I argue that instead of shutting down distribution avenues, NIST should be
making
additional ones available.

A lot has been said lately about how rapidly our technology is exploding.
But think
about how much of that is critically dependent on precision time transfer
over the
planet, and how much longer it would take mankind to recover from (insert
your favorite
disaster here) without good time and frequency transfer still up and
working.

Dana

On Sun, Aug 12, 2018 at 2:06 PM, djl djl@montana.com wrote:

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and follow the instructions there.

On Sun, Aug 12, 2018 at 07:48:52PM -0400, Bob kb8tq wrote:

Not so clear, big events can cause satellites to fail due to

large charges and voltages on induced on surfaces of the bird that cause
arcs - and also bombardment by energetic particles that can cause logic
states in chips to get tweaked (SEDs) and crash the control electronics
and CPUS and/or confuse vital sensors..  causing the bird to enter modes
that may not be safe for it or recoverable - more than a few satellites
have died of these kinds of things.

Whether ENOUGH GPS/Galileo/Glonnass/Baideu birds would fail to

eliminate them as a functioning constellation is probably somewhat
unlikely... however.

But It is much more likely that orbits would be less accurately

known for a while due to atmospheric heating and increased drag and
maybe also due to disturbances in satellite orientation and power and
thermal status during the event that could both change drag and perhaps
even induce slight impulses if gas jets or similar means were required
to recover the bird and make it stable again.  And the power and
thermal perturbations in emergency mode shutdown configurations might
well impact the on board clock performance and accuracy (even maybe just
from the extra radiation as the magnetopause moved inside the satellite
orbits in an extreme event).

So in addition to the disturbed propagation through the

ionosphere causing degraded performance there well could be significant
errors in ephemerides (basic bird position) that would do so too for a
while.

And recovering a whole constellation of confused, sick and 

dangerously misconfigured satellites during a massive world wide event
might be less easy than one might first imagine as the resources
required on the ground would probably be damaged and disabled by other
effects (massive nation wide power grid collapses and the like) and
would certainly be stretched thin by all the urgent problems to get
under control before individual  satellites started to become nearly or
completely unrecoverable.

And there are certainly positive feedback vicious spiral effects

here - such as lack of time and position accuracy caused secondary
problems such as  sync failures in fiber rings and the like that might
take out parts of the Internet and cell systems) and make it much harder
to recover the satellites due to lack of effective communications on the
ground.

I'd expect that decently designed HF and LF radio time and

positioning systems would be VERY much more resistant to lethal damage
by flare EMPs... hard to see how massive earth magnetic events could
kill LF or HF receivers that were even modestly hardened against EMP
simply because otherwise local lightning would be frying them regularly.

And the HF and LF transmitters involved should be pretty self

protecting too... maybe their power supply would be the weak point as
the grid collapsed but this is a problem that can be cheaply handled
with well known and proved diesel generator technology.

--
Dave Emery N1PRE/AE, die@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."

There have been a few television documentaries over the years on the Carrington event of 1859.

https://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event

-=Bryan=-

From: time-nuts time-nuts-bounces@lists.febo.com on behalf of David I. Emery die@dieconsulting.com
Sent: August 12, 2018 6:36 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bicentennial GOES satellite clock

On Sun, Aug 12, 2018 at 07:48:52PM -0400, Bob kb8tq wrote:

    Not so clear, big events can cause satellites to fail due to

large charges and voltages on induced on surfaces of the bird that cause
arcs - and also bombardment by energetic particles that can cause logic
states in chips to get tweaked (SEDs) and crash the control electronics
and CPUS and/or confuse vital sensors..  causing the bird to enter modes
that may not be safe for it or recoverable - more than a few satellites
have died of these kinds of things.

    Whether ENOUGH GPS/Galileo/Glonnass/Baideu birds would fail to

eliminate them as a functioning constellation is probably somewhat
unlikely... however.

    But It is much more likely that orbits would be less accurately

known for a while due to atmospheric heating and increased drag and
maybe also due to disturbances in satellite orientation and power and
thermal status during the event that could both change drag and perhaps
even induce slight impulses if gas jets or similar means were required
to recover the bird and make it stable again.  And the power and
thermal perturbations in emergency mode shutdown configurations might
well impact the on board clock performance and accuracy (even maybe just
from the extra radiation as the magnetopause moved inside the satellite
orbits in an extreme event).

    So in addition to the disturbed propagation through the

ionosphere causing degraded performance there well could be significant
errors in ephemerides (basic bird position) that would do so too for a
while.

    And recovering a whole constellation of confused, sick and

dangerously misconfigured satellites during a massive world wide event
might be less easy than one might first imagine as the resources
required on the ground would probably be damaged and disabled by other
effects (massive nation wide power grid collapses and the like) and
would certainly be stretched thin by all the urgent problems to get
under control before individual  satellites started to become nearly or
completely unrecoverable.

    And there are certainly positive feedback vicious spiral effects

here - such as lack of time and position accuracy caused secondary
problems such as  sync failures in fiber rings and the like that might
take out parts of the Internet and cell systems) and make it much harder
to recover the satellites due to lack of effective communications on the
ground.

    I'd expect that decently designed HF and LF radio time and

positioning systems would be VERY much more resistant to lethal damage
by flare EMPs... hard to see how massive earth magnetic events could
kill LF or HF receivers that were even modestly hardened against EMP
simply because otherwise local lightning would be frying them regularly.

    And the HF and LF transmitters involved should be pretty self

protecting too... maybe their power supply would be the weak point as
the grid collapsed but this is a problem that can be cheaply handled
with well known and proved diesel generator technology.

--
Dave Emery N1PRE/AE, die@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@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Craig,

The original main reason for WWVB had nothing to do with syncing our
"atomic"
wristwatches and clocks.  It was for keeping local frequency standards
honest, for
which continuous coverage throughout the day and night was desirable (if not
always achievable).  But for that application, a one-shot daily sync was
not really
good enough (for most users).  Stations that used WWVB for serious purposes
used
outdoor electrostatically-shielded loop antennas, usually up on the roof,
to get
enough signal enough of the time.

I'm curious about your fan-related interference.  Fans of the kind used for
"cooling"
living space generally use induction motors, which per se have no mechanism
for
generating RFI.  However, more modern fans sometimes have digital control
systems, which of course do include built-in RFI generators.    I wonder
which variety
you're using.

My Casio watch (module 3405) seems to sync reliably at night if held in a
favorable
orientation through the exercise, but if worn on the wrist at random but
changing
orientation, it often misses.  Fortunately mine seems to drift only about 1
sec per
month when "free running", so I now leave auto-sync turned off and just do
a single
forced sync every few weeks when I decide it's getting "too far off" based
on WWV.

Dana

On Sun, Aug 12, 2018 at 10:40 AM, Craig Kirkpatrick craigk46@comcast.net
wrote:

 This function of disseminating a frequency reference is not mentioned at all in the NIST request for information document, nor in  Microsemi’s response.

I expect most calibration labs have their own 5071As  but that is not quite the same as having a NIST traceability. My Certificate of Calibration from SRS for one of my PRS10 rubidium standards indicates:
«  Stanford Research Systems, Inc. certifies that this instrument has been calibrated to manufacturer specifications and accuracy at an ambient temperature of 23° +/- using instruments and standards which are traceable to the National Institute of Standards and Technology. «
I expect the big labs send their instruments of to Boulder for calibration, but there must be some smaller outfits still phase locking off WWVB. We in Europe have MSF, DCF and TDF for which off air frequency references are /were available and which are probably still being used.
How would this frequency traceability work if WWVB/WWVH pass to a private enterprise?

Don’t worry about how powerful the machines are. Worry about who the machines are giving  power to.

I'm trying hard to think of routine users of WWV / WWVH other than amateur radio operators, time nuts, and the occasional academic / scientific study that uses the transmitters as a signal source.

Perhaps some boaters still use the time signals to set their chronometers, but WWV /WWVH probably wouldn't be my first choice for that application if I had access to GPS.

Perhaps some other users of the radio Spectrum occasionally use the signals as a basic test signal ?

I use the time signals for my amateur radio hobby when I already have an HF receiver and don't want to mess with using GPS as a time source.  I only need accuracy within perhaps a third of a second so manually setting a computer clock while listening to WWV works for me.

For my own interest I'd be curious in knowing of other routine uses of the WWV / WWVH time signals.

Mark S
VE7AFZ

mark@alignedsolutions.com
604 762 4099