My 37 year old Rolex day-date gains less than 2 sec/day compared to GPS clock.
Rolex standard is +6/-2 sec/day.

Regards, NL7F

On Mon, 5 Mar 2018 01:38:06 -0500, Don Murray via time-nuts wrote:

Bill Beam
NL7F

Hi Bill...
 
My Rolex GMT Master was stolen back in '75,
so no luck on that.  Rolex is a bit pricey for
my needs.
 
My Seiko CQ001M, one of the first Seiko Digitals,
was amazing.  Over the time I had it, it varied less
than plus/minus 1 second against WWV.  I carried
a Radio Shack Time Kube with me, when I was
challeneged, as to the accuracy of that watch!  
It died many years later, and the replacement
innards were totally "loose!"
 
Yes, I think that Time Kube qualifies me as a
"Old School Time Nut!  ;-)
 
TNX Bill.
 
73
Don
W4WJ
 
In a message dated 3/5/2018 1:31:04 AM Central Standard Time, wbeam@gci.net writes:

 
My 37 year old Rolex day-date gains less than 2 sec/day compared to GPS clock.
Rolex standard is +6/-2 sec/day.

Regards, NL7F

On Mon, 5 Mar 2018 01:38:06 -0500, Don Murray via time-nuts wrote:

Bill Beam
NL7F

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and follow the instructions there.

I wore a Casio "Atomic" watch and it set itself reliably for many years
until very recently. They are still available.  I've replaced it with a
Seiko Solar "Radio" watch which I understand has a better wwvb receiver
in it. Haven't worn it yet so I'm not sure how it will perform but I've
heard good comments.
Bill

On 3/5/2018 1:38 AM, Don Murray via time-nuts wrote:

Even my pre civil war pocket watches should be good enough
for your needs.  Better than a minute/day.

But for some (many) time-nuts it's about wants, not needs.

My clocks and watches that can be heard across the room qualify
me as old school time nut.  (My DOB qualifies me as just plain old.)

On Mon, 5 Mar 2018 03:20:40 -0500, Don Murray via time-nuts wrote:

Bill Beam
NL7F

On Mon, 5 Mar 2018 01:38:06 -0500
Don Murray via time-nuts time-nuts@febo.com wrote:

I've owned several Swatch and Tissot over the past decades,
Growing up in Switzerland does that to you. :-)

I currently have a Tissot P-Touch (first generation) and
a Swatch Irony in active use. Both are accurate enough
that I only set them twice a year (DST switch) and they
are usually off by less than 10s. Which is good enough
for my needs as a wristwatch.

So I guess, go for any modern Swiss quartz watch :-)

		Attila Kinali

--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson

Hi

If you want to stick with WWV, the Citizen “Ecco Drive” (solar) WWVB
watches are a pretty good option. Until I caved in to the wonders of
a cell phone on my wrist, I used them for many years. Nothing to fuss
with. No battery to die on you. Always keeps the right time. Available
in titanium. The only drawback is the limited number of styles they
make it in. You may or may not see one you like the looks of.

Bob

Am 05.03.2018 um 14:01 schrieb Bob kb8tq:

ECO-Drive

I second that. In Europe, it synchronizes to DCF77 and in
Japan to Fukushima, if that should be operational again.

I wonder how they make it, that it lives from just a few
photons now & then, year after year.

Gerhard

For those of us whose time-nuttery extends into the fascinating world of
mechanical watches and clocks, the kind of accuracy usually discussed here
is not only impossible but essentially irrelevant (quelle horreur!). Our
interest is in the beauty and elegance of micromechanical devices that have
evolved over centuries. When I look down at one of the 25 or so
wristwatches in my small collection or up at the ten wall and floor clocks
in my home, I am seeing far more than merely the time. If all I want is the
time, I can always glance at my phone or go to the basement and fiddle with
one or another of the electronic devices there.

My oldest watch, a Waltham Model 57, has been running continuously for 150
years and still keeps time within a minute per day. Horology is about so
much more than crystals and resonances and Allen deviations.

On Monday, March 5, 2018, Gerhard Hoffmann dk4xp@arcor.de wrote:

--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu

If you are into rugged, I have a casio atomic solar that special forces use…

I was able to tail-end a gov’t contract and got it for cheap.

aren’t we silly.

Regards,

Jerry

Jerry Hancock
jerry@hanler.com
(415) 215-3779

An by the way, I also have a Tissot P-touch as a retirement gift from IBM.  Got the watch, as they say.  I can say it is very accurate for a non-disciplined watch if you wear it every day.

Regards,

Jerry

Jerry Hancock
jerry@hanler.com
(415) 215-3779

On Mon, 5 Mar 2018 07:45:51 -0800
Jerry Hancock jerry@hanler.com wrote:

Even if you do not wear it, it's very accurate. I guess they use
the internal termperature sensor to compensate the crystal.
How they get to sub-ppm stability over half a year, I have no clue.
And this one is almost 20 years old.

		Attila Kinali

--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil Stephenson

I really don't want a conductive metal-case watch on my arm. What I do
want is a light-weight, thin watch with day, date and analog display
with sweep second hand. Not digital... Ok, that may be old-fashioned but
it suits me. I've never found a suitable wwvb watch.

So, I opt for an inexpensive (<$50) Swatch. Very light-weight, thin,
plastic case, plastic band, all non-conductive. And,
externally-replaceable power button cell.

Accuracy? Ok, not TimeNut accuracy but I find mine is accurate to 5
seconds per month. And, the second hand is settable.

I do carry an Android cell phone; its clock is always a few seconds off.
I use an app, Sol Et Umbra, that reads the internal GPS clock for
displayed time and it also displays the difference between NTP and the
phone internal clock. This is a sundial design/interpretation app but it
gives the time of local solar noon (sun meridian transit), a value I use
rather often. It is written by a prominent sundial enthusiast, is free
and has no advertisements; it does lots more, too.

But, honestly, I usually just look at my analog Swatch!

Larry W6FUB

On 3/5/2018 7:45 AM, Jerry Hancock wrote:

--
Best wishes,

Larry McDavid W6FUB
Anaheim, California  (SE of Los Angeles, near Disneyland)

Eurochron (I believe they're low-end brand of Junghams) make a plastic
DCF77 watch. 'Plastic' doesn't do it justice - although the one I had
eventually wore away, it was attractive and well made and lasted for
several years.

I think this is the WWVB equivalent.

http://www.radiocontrolledclock.com/ateuransporw4.html

On Mon, Mar 5, 2018 at 4:19 PM, Larry McDavid lmcdavid@lmceng.com wrote:

And that is just my point--well, part of it, anyway--ultra-precise
measurement of time is profoundly important, and rightly the primary focus
of this group. But for the wrist, very, very few of us need pin-point
accuracy--though many seem to perceive that we do. My Tissot mechanical
chronograph is right now doing a fantastic job of timing the eggs I'm
boiling for my lunch.

On Monday, March 5, 2018, Larry McDavid lmcdavid@lmceng.com wrote:

--
Patriotism is supporting your country all the time, and your government
when it deserves it.
--Mark Twain

We may be surprised at the people we find in heaven. God has a soft spot
for sinners. His standards are quite low.
--Desmond Tutu

Lots of folks have chimed in on this thread, but I will just add that the Apple watch is an NTP client. I’m extremely happy with mine, but the reasons I am are far, far wider than its accuracy (which I can only judge by eye, which is an extraordinary low bar for a Time Nut).

I think what makes the IWatch unique is it has an option that makes it a standalone cell phone. With this new option it no longer need to be in proximity of you IPhone. You leave the IPhone at home and have a fully function cell phone on your wrist. The only hitch is they will not let you active a watch separately, it must be tied to you IPhone number.

Garmin also make some nice sport watches that a fully functional GPS receivers. Everything but a one PPS and 10MHz output.

Cheers;

Thomas Knox

From: time-nuts time-nuts-bounces@febo.com on behalf of Nick Sayer via time-nuts time-nuts@febo.com
Sent: Monday, March 5, 2018 10:13 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Need a Watch Recommendation

Lots of folks have chimed in on this thread, but I will just add that the Apple watch is an NTP client. I’m extremely happy with mine, but the reasons I am are far, far wider than its accuracy (which I can only judge by eye, which is an extraordinary low bar for a Time Nut).

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On 3/5/2018 7:38 AM, Don Murray via time-nuts wrote:

For non-formal, day-to-day wear, I've been partial to Casio G-Shock
watches for a long time. They're rugged, reliable, and have the basic
features one might want: stopwatch, countdown timer, a few user-settable
alarms, etc. without too many bells and whistles.

Watches with "Multi-Band 6" have long wave time signal receiving
capability and can receive signals from WWVB, MSF, DCF77, and
transmitters in China and Japan.

They also make watches that have GPS receivers, and hybrid GPS and long
wave receivers for redundancy.

I've worn a GWM850-1, which is a Multi-Band 6 watch, for a long time and
it's served me well. Unfortunately, Casio doesn't make that specific
model anymore, but there's lots of other similar models available. Mine
tries to set itself every night starting at midnight and trying again
hourly until it either succeeds at setting the time or it fails after
4:00am. It also charges its internal battery from a solar panel formed
into the watch face, so one never (modulo the battery eventually
degrading) needs to change it. I've found that even with liberal use of
the EL backlight, the battery never gets below the "medium" level during
winter when the watch rarely sees the sun, and then fully charges up
again in springtime.

Cheers!
-Pete

--
Pete Stephenson

Nice but lacks "day” feature (has “date”). I don’t normally care whether
it’s the 22nd or the 23rd but it’s nice to know whether it’s Tuesday or
Wednesday. YMMV, of course.

Jeremy

On Wed, Mar 14, 2018 at 1:57 PM Achim Vollhardt avollhar@physik.uzh.ch
wrote:

--
Sent from my iPad 4.

On 5 March 2018 at 16:50, William H. Fite omniryx@gmail.com wrote:

What is the most demanding task one would use a wrist watch for? The doors
on trains in the UK lock up to 30 s before the train is due to leave. It is
most frustrating to arrive at a platform, with the train stationary, but no
way to get in. I would estimate that about 20 seconds is good enough for
making a decision about just how fast one has to run for a train.

Buying tickets for events like Wimbledon tennis in the UK can demand one
attempts at the right time, as tickets become available and sold out very
quickly. But one would be using a computer to purchase them, so I don't
think that comes under the requirements of a wrist watch.

Dave

On Wed, Mar 14, 2018, at 6:53 PM, Dr. David Kirkby wrote:

It depends on your job or hobby.

During the Apollo 13 rocket burn before their emergency re-entry, Jack
Swigert used a wrist watch to time the retrorocket burn which was
manually controlled by Jim Lovell. Their normal capsule chronometer was
inoperative. This was mostly a differential (time interval) timing
measurement.
If you needed to determine your location (longitude) and all you had
was a wristwatch and a sextant (and software or a table with certain
information), the accuracy of the distance calculation would depend on
the absolute time accuracy of the watch. At the equator the longitude
error due to time error is (40,075.16 km/day) / (86,400 sec/day) =
463.8 m/sec.
Amateur astronomers need to know time accurate to about a second or
better for accurate osculation observations.
Amateur Radio nets and phone, Skype for Business, or WebEx conference
calls usually start pretty close to the scheduled time. In some cases
people start wondering if the organizer is delayed after about 15 to
30 seconds.--
Bill Byrom N5BB

I concur with Bill.  And even if one keeps tabs on the current watch error,
as is the usual practice by celestial navigators, once that error reaches
or exceeds more than a minute the process frankly gets more clumsy and
error prone.  And if a watch drifts in time very rapidly, one loses faith
in its
ability to coast at a known rate between checks against WWV, which
opportunities are not always available when one wants, due to
propagation issues.

Whatever happened to the quartz watches with trimmer capacitors
for setting the rate?

And radio controlled?  No way!
The process is to delicate and marginal to rely upon.  Give me a
good stable free-running watch any day.

I don't like the solar watch concept mainly because one sometimes
has to go for weeks without an opportunity to expose his watch to
direct sunlight (or some indoor equivalent) for the requisite period
of several hours.

Yesterday I was reading the manual for the Citizen ECO series,
and that thing requires far too much effort and complication to keep
it working and on time.  A good watch must simply work, with no
maintenance beyond occasional battery replacements (and possible
gland replacement at battery-change time), and accurately enough
that the time need never be reset between battery replacements.

I use an old quartz diving watch I bought just under 10 years ago,
(brand no longer distinguishable), which has never drifted more than
about 30 sec (usually less) between battery replacements, and I never
take it off between batteries except when compelled to do so at TSA
checkpoints.  Aside from its LCD's failing I'd be happy to use if forever,
but it's getting awfully hard to read these days.

Dana

On Wed, Mar 14, 2018 at 10:54 PM, Bill Byrom time@radio.sent.com wrote:

Hi

Trimmer caps to set watch crystals are problematic. They are a source of error
as well as a set mechanism. You bump this or that and the trimmer moves. They
also cost money to buy and install properly (no flux in-between the plates …).
Once that is all done you need a way to set them in the factory. Back in the day,
yes, we hat line workers who did that sort of thing. We also sold the crystal in the
watch module (not the whole module) for $2 once upon a time.

How close do you want to set it? In our case, the set was supposed to be < 0.5
ppm of the target. Ideally you needed a design that would do a small fraction
of a ppm in a typical situation.

If the trimmer is a normal device, you get about 120 degrees of travel for the
useful part of the tuning curve. A tune range of 30 ppm for the crystal and another
20 ppm for the other parts would not be unusual. Even taking the 0.5 ppm number,
you are into 120 / 100 = 1.2 degrees sort of set on that little trimmer.

Bottom line: They went away because they weren’t good enough and they were
to expensive …. Setting a modern “shoot the chip” register based module is way
more accurate and reliable. It’s silicon so the cost is whatever sand is selling
for ….

Bob

Most of the quartz watches I've owned were off by about 1-2 minutes per
month,
which I consider inexcusable.

Agreed, the mechanical trimmer is rather problematical, but I'd sure like
to see
*something *that the sophisticated user can tweak at home. Measurement of
the
current rate error is probably not much of a problem; I once tried seeing
the
32kHz signal in the watch by capacitive coupling to the face, and could
detect
the signal.  I just tried a token attempt on my current watch and failed,
but it
was a crude, unshielded attempt by merely laying a 'scope probe against the
watch face.  I was being severely jammed by the local 1230 kHz AM station.
Anyway, the idea is to observe the signal's phase drift while triggering
the 'scope
from a trusted 1PPS source.

So now all that's needed is an alternate way for trimming the watch's
frequency
without opening the case.  There must be a way...

Dana

On Thu, Mar 15, 2018 at 8:13 AM, Bob kb8tq kb8tq@n1k.org wrote:

Dana, the magnetic impulse of a quartz watch stepping the second hand forward is easily picked up by an unshielded coil. Wind a couple hundred turns of magnet wire around a bottle cap and hold near the watch face. Plug into the microphone input of a PC and run audacity to record the waveform. You will see 60Hz/120Hz buzz in the background but the second hand stepping impulses will clearly show as a sharp impulse every second. Of course a small electret microphone can pick up the sonic impulse too and will also be useful for purely mechanical watches.

Broadly I’ve found cheapie quartz watches to be way more accurate than a minute a month. In the past I’ve marveled here about my cars clock which drifts less than a minute every 6 months (DST change reset interval) despite being in a very adverse temperature range.

Tim N3QE

Hi

The most common way to pull the 32KHz signal off of a watch is via a tuned
microphone. At least that’s the way we did it in production. A watch crystal
can (but usually doesn’t) move > 100 PPM with temperature. When things
are set up, assumptions are made about “your” temperature environment. If
the watch is off temperature vs the assumptions, it will not keep good time.

Some numbers:

10 seconds a month is 3.8 ppm
120 seconds a month is 46 ppm

The temperature curve is parabolic so usually temperature will result in a
slow watch. If the “target” set point is 10 seconds fast, you would need to
be right at 50 ppm off to loose two minutes a month.

If you take a look a the previous numbers on trim range on the trimmer. A
trimmer that will do +/- 25 ppm is “adequate” for setting the watch in production.
It’s not good enough (by a factor of 2) to take care of a 2 minute / month timing
error.

Just for the record, I don’t think I have ever owned a quartz watch that was
off by more than a 15 seconds per month. I’ve owned cheap ones and expensive
ones. They all have done pretty well. The fancy ones have done better ….

Bob