Time Standard Dilemma

[Al]

Due to the recent time change, I went about to adjust all of the clocks
in my house, digital and analog. This past summer, I had purchased a new
wristwatch, a Citizen Eco-Drive powered by light. I had set this watch
by the clock on my GPS.

When it came time to set my clocks, I rechecked my wrist watch against a
recently acquired "atomic clock" which is set by radio waves from NIST.
They differed by about 15 seconds. Hmmm, wrist watch must has slowed
down. For chuckles, I checked against the GPS. No, it was accurate.

I then compared the GPS clock to the "atomic clock" and found the 15
second difference. And as far as I can tell, it is exactly 15 seconds.
repeated attempts to resynchronize the "atomic clock" to the NIST
standard always results in a 15 sec. difference.

OK, I bet the "atomic clock" is the culprit for three reasons:

1: The GPS clock agrees with the local broadcast beef from the radio
station

2: The GPS cost about 20 times the "atomic clock."

3: The GPS clock agrees with the computer clock which is also
synchronized by the internet.

Could it be that the circuity in the "atomic clock" takes 15 seconds to
adjust the output? If so, why not compensate for this?

Any ideas?

Al

PS:

 

[Ken Smith]

In article <no.spam-551326.09025404042005@news.verizon.net>,
Al <no.spam@wanted.com> wrote:
[... GPS vs "atomic clock" ..]

Could it be that the circuity in the "atomic clock" takes 15 seconds to
adjust the output? If so, why not compensate for this?

Any ideas?

The GPS time reported from a real GPS will always be a little late. The
time is the time of the fix and the fix happened at the edge of the 1PPS
pulse. The actual message data is sent after it is calculated and is
thus just a little late.

What I suggest happened:
An "Atomic clock" must make some sort of calculations internally to
determine the time. It would be reasonable for the very slow processor
involved to take. lets say, 7.5 seconds to do this computation. The
designers then "corrected for this" by adding a 7.5 Second delay. Since
all the devices showed exactly the same time, the PHB thought they were
also accurate and cut off the funding for all further testing and
development.
--
--
kensmith@rahul.net forging knowledge

 

[John Woodgate]

I read in sci.electronics.design that Al <no.spam@wanted.com> wrote (in
<no.spam-551326.09025404042005@news.verizon.net&gt about 'Time Standard
Dilemma', on Mon, 4 Apr 2005:

Could it be that the circuity in the "atomic clock" takes 15 seconds to
adjust the output? If so, why not compensate for this?

You clock is tuned to a special NIST transmission intended for clocks on
a CIA space station 2.79 million miles out.
--
Regards, John Woodgate, OOO - Own Opinions Only.
There are two sides to every question, except
'What is a Moebius strip?'
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Jim Thompson]

On Mon, 4 Apr 2005 15:14:58 +0100, John Woodgate
<jmw@jmwa.demon.contraspam.yuk> wrote:

I read in sci.electronics.design that Al <no.spam@wanted.com> wrote (in
no.spam-551326.09025404042005@news.verizon.net&gt about 'Time Standard
Dilemma', on Mon, 4 Apr 2005:

Could it be that the circuity in the "atomic clock" takes 15 seconds to
adjust the output? If so, why not compensate for this?

You clock is tuned to a special NIST transmission intended for clocks on
a CIA space station 2.79 million miles out.

By the time WWVB spits out the full complement of "set" bits, at
1/sec, 35 seconds has elapsed.

So the information should be corrected and used to set the clock at
the occurrence of the next "PP" marker bit.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Joerg]

Hello Al,

Whenever I compared my "atomic clock" against WWVH on shortwave it was
always accurate.

Regards, Joerg

http://www.analogconsultants.com

 

[Al]

In article <ESe4e.7910$FN4.3642@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:

Hello Al,

Whenever I compared my "atomic clock" against WWVH on shortwave it was
always accurate.

Regards, Joerg

http://www.analogconsultants.com

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

Al

 

[martin griffith]

On Mon, 04 Apr 2005 19:45:35 GMT, in sci.electronics.design Al
<no.spam@wanted.com> wrote:

In article <ESe4e.7910$FN4.3642@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:

Hello Al,

Whenever I compared my "atomic clock" against WWVH on shortwave it was
always accurate.

Regards, Joerg

http://www.analogconsultants.com

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

Al
You dont listen to digital radio then!

martin


Opinions are like assholes -- everyone has one

 

[Joerg]

Hello Al,

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

I don't have a GPS. However, the WWVB clock also agrees with the
stations, at least around Sacramento.

Regards, Joerg

http://www.analogconsultants.com

 

[Thomas Magma]

You could be seeing the difference between GPS time and UTC time. It has to
do with GPS's inability to adjust for leap seconds. Here is a link that
explains this.

http://gpsinformation.net/main/gpstime.htm

"Al" <no.spam@wanted.com> wrote in message
news:no.spam-551326.09025404042005@news.verizon.net...

Due to the recent time change, I went about to adjust all of the clocks
in my house, digital and analog. This past summer, I had purchased a new
wristwatch, a Citizen Eco-Drive powered by light. I had set this watch
by the clock on my GPS.

When it came time to set my clocks, I rechecked my wrist watch against a
recently acquired "atomic clock" which is set by radio waves from NIST.
They differed by about 15 seconds. Hmmm, wrist watch must has slowed
down. For chuckles, I checked against the GPS. No, it was accurate.

I then compared the GPS clock to the "atomic clock" and found the 15
second difference. And as far as I can tell, it is exactly 15 seconds.
repeated attempts to resynchronize the "atomic clock" to the NIST
standard always results in a 15 sec. difference.

OK, I bet the "atomic clock" is the culprit for three reasons:

1: The GPS clock agrees with the local broadcast beef from the radio
station

2: The GPS cost about 20 times the "atomic clock."

3: The GPS clock agrees with the computer clock which is also
synchronized by the internet.

Could it be that the circuity in the "atomic clock" takes 15 seconds to
adjust the output? If so, why not compensate for this?

Any ideas?

Al

PS:

 

[Guy Macon]

Al wrote:

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

At least two of my local radio stations are 15 seconds off at the
beep because they use a delay to seamlessly remove coughing.

Could you give us the brand and model of your "recently acquired
'atomic clock'"?

 

[Michael]

Al wrote:

In article <ESe4e.7910$FN4.3642@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:

Hello Al,

Whenever I compared my "atomic clock" against WWVH on shortwave it was
always accurate.

Regards, Joerg

http://www.analogconsultants.com

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

Al

I can see it now: radio station hacks their clock to GPS.
If so, of course they'd agree.

 

[no_one]

The present GPS-UTC delta is 13 seconds (I have a time server at work that
displays the difference).


"Thomas Magma" <somewhere@overtherainbow.com> wrote in message
news:h%h4e.898345$8l.384175@pd7tw1no...

You could be seeing the difference between GPS time and UTC time. It has
to
do with GPS's inability to adjust for leap seconds. Here is a link that
explains this.

http://gpsinformation.net/main/gpstime.htm

"Al" <no.spam@wanted.com> wrote in message
news:no.spam-551326.09025404042005@news.verizon.net...
Due to the recent time change, I went about to adjust all of the clocks
in my house, digital and analog. This past summer, I had purchased a new
wristwatch, a Citizen Eco-Drive powered by light. I had set this watch
by the clock on my GPS.

When it came time to set my clocks, I rechecked my wrist watch against a
recently acquired "atomic clock" which is set by radio waves from NIST.
They differed by about 15 seconds. Hmmm, wrist watch must has slowed
down. For chuckles, I checked against the GPS. No, it was accurate.

I then compared the GPS clock to the "atomic clock" and found the 15
second difference. And as far as I can tell, it is exactly 15 seconds.
repeated attempts to resynchronize the "atomic clock" to the NIST
standard always results in a 15 sec. difference.

OK, I bet the "atomic clock" is the culprit for three reasons:

1: The GPS clock agrees with the local broadcast beef from the radio
station

2: The GPS cost about 20 times the "atomic clock."

3: The GPS clock agrees with the computer clock which is also
synchronized by the internet.

Could it be that the circuity in the "atomic clock" takes 15 seconds to
adjust the output? If so, why not compensate for this?

Any ideas?

Al

PS:

 

[Al]

In article <8d6351h4t4sp46hndhllgsbvjag9fmqjju@4ax.com>,
martin griffith <martingriffith@XXyahoo.co.uk> wrote:

On Mon, 04 Apr 2005 19:45:35 GMT, in sci.electronics.design Al
no.spam@wanted.com> wrote:

In article <ESe4e.7910$FN4.3642@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:

Hello Al,

Whenever I compared my "atomic clock" against WWVH on shortwave it was
always accurate.

Regards, Joerg

http://www.analogconsultants.com

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

Al
You dont listen to digital radio then!


If it ain't free, I don't bother.

Al

 

[Al]

In article <9ol4e.545$An2.248@newsread2.news.pas.earthlink.net>,
"no_one" <no_one@earthlink.net> wrote:

The present GPS-UTC delta is 13 seconds (I have a time server at work that
displays the difference).


"Thomas Magma" <somewhere@overtherainbow.com> wrote in message
news:h%h4e.898345$8l.384175@pd7tw1no...
You could be seeing the difference between GPS time and UTC time. It has
to
do with GPS's inability to adjust for leap seconds. Here is a link that
explains this.

http://gpsinformation.net/main/gpstime.htm

<big snip>

OK, these are the most reasonable explanations. But then, what is legal
time for court cases? 15 secs., or so, may not be much, but at 60 miles
an hour it is.

Al

 

[Al]

In article <1153ev1cpkeuu99@corp.supernews.com>,
Guy Macon <_see.web.page_@_www.guymacon.com_> wrote:

Al wrote:

Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

At least two of my local radio stations are 15 seconds off at the
beep because they use a delay to seamlessly remove coughing.

Could you give us the brand and model of your "recently acquired
'atomic clock'"?

I just checked the clock and it has no brand name. Hmmm. It was made in
China and sold at Walgreens for about $10 US. Aside from the 15 sec. or
so discrepancy, it works just great. All it says on it is, "Atomic
Clock." And I have seen it synchronize.

Could this be a plot to screw with our minds ;-)

Al

 

[Jim Thompson]

On Tue, 05 Apr 2005 12:00:41 -0400, Phil Hobbs
<pcdh@SpamMeSenseless.us.ibm.com> wrote:

Al wrote:
In article <1153ev1cpkeuu99@corp.supernews.com>,
Guy Macon <_see.web.page_@_www.guymacon.com_> wrote:


Al wrote:


Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

At least two of my local radio stations are 15 seconds off at the
beep because they use a delay to seamlessly remove coughing.

Could you give us the brand and model of your "recently acquired
'atomic clock'"?



I just checked the clock and it has no brand name. Hmmm. It was made in
China and sold at Walgreens for about $10 US. Aside from the 15 sec. or
so discrepancy, it works just great. All it says on it is, "Atomic
Clock." And I have seen it synchronize.

Could this be a plot to screw with our minds ;-)

Al

Ah, you must be one of those new-fangled digital-type guys who think
that real men need 8-digit alarm clocks... We analog geezers would just
rotate the second hand by 90 degrees.

Cheers,

Phil Hobbs

Snicker ;-)

However, being an "analog geezer" doesn't necessarily mean everything
is best as analog...

My wife talked me into buying a _beautiful_ Omega watch ($2400) that
is self-winding. It won't stay ticking for more than about 12 hours,
if you're not an arm waver.

So I wear my $20 Timex Indiglo Digital... and it keeps perfect time
;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Keith Williams]

In article <4252B629.4060109@SpamMeSenseless.us.ibm.com>,
pcdh@SpamMeSenseless.us.ibm.com says...

Al wrote:
In article <1153ev1cpkeuu99@corp.supernews.com>,
Guy Macon <_see.web.page_@_www.guymacon.com_> wrote:


Al wrote:


Check it against your GPS. I know my GPS agrees with the local radio
station "beeps" on the hour almost exactly.

At least two of my local radio stations are 15 seconds off at the
beep because they use a delay to seamlessly remove coughing.

Could you give us the brand and model of your "recently acquired
'atomic clock'"?



I just checked the clock and it has no brand name. Hmmm. It was made in
China and sold at Walgreens for about $10 US. Aside from the 15 sec. or
so discrepancy, it works just great. All it says on it is, "Atomic
Clock." And I have seen it synchronize.

Could this be a plot to screw with our minds ;-)

Al

Ah, you must be one of those new-fangled digital-type guys who think
that real men need 8-digit alarm clocks... We analog geezers would just
rotate the second hand by 90 degrees.

This is one "digital-type" that doesn't need no steenkin' alarm clock
(haven't worn a watch in 20 years either). I only set an alarm when my
schedule changes drastically (like to catch a 5AM flight) and even then
I wake up before it goes off 9/10 times. Oh, and I never set the
bedroom clock to back standard time. Damned Chineese-digital-types
don't seem to understand the 'U' in UI.

--
Keith

 

[Peter Bennett]

On Tue, 05 Apr 2005 12:54:04 GMT, Al <no.spam@wanted.com> wrote:

In article <9ol4e.545$An2.248@newsread2.news.pas.earthlink.net>,
"no_one" <no_one@earthlink.net> wrote:

The present GPS-UTC delta is 13 seconds (I have a time server at work that
displays the difference).

The difference between the time used internally by the GPS system and

UTC is 13 seconds, but that difference and/or the correct UTC time is
included in the data sent by the satellites, so that GPS receivers can
display UTC.



--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

 

[douglas dwyer]

In message <76e55159vc0ac6k3i0an35mjth257qi4lm@4ax.com>, Jim Thompson
<thegreatone@example.com> writes

My wife talked me into buying a _beautiful_ Omega watch ($2400) that is
self-winding. It won't stay ticking for more than about 12 hours, if
you're not an arm waver.
The first Quartz Watch (as far as I know) was the Omega Megaquartz still

possibly the most accurate unsynchronised) as it employed an AT cut with
its superior aging and tempco at a binary 2MHz (we did the crystal in
the UK)
Priced in the early 70s out of reach of the masses it was not a success.
Find one as a future investment if you can

--
dd

 

[douglas dwyer]

In message <4254dd05.12068890@news.plus.net>, Don Pearce
<donald@pearce.uk.com> writes

AT cut at around human body temperature is far from stable
Nice to discuss.

AT cut Tc rotates about 27C as the angle of cut varies. Therefore one
can expect a symmetrical excursion about this temperature.
Average wrist watch temp will be below body temp and an optimally cut AT
could give +-1ppm without compensation 10 to 44C and if clean and well
encapsulated <1ppm per year.
I.e. a few seconds/year.
--
dd