Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Computer Support > Time synch

Reply
Thread Tools

Time synch

 
 
=?ISO-8859-1?Q?R=F4g=EAr?=
Guest
Posts: n/a
 
      08-23-2007
A few days ago there were some posts regarding which server to use to
synch time and I tried the NASA server. Worked fine, except it was
nearly two minutes off from one of those "atomic clocks" I keep near the
computer desk. I know it's not atomic, it picks up a radio signal from
the U.S. defense system. But still, two minutes is a large degree of
latitude of accuracy. But just now, 5AM here, I just checked the two
together again, and they only disagree by about 8 seconds. I don't have
a question I guess, unless you know an explanation for this.
 
Reply With Quote
 
 
 
 
Dogpoop
Guest
Posts: n/a
 
      08-23-2007
Rgr wrote:
> A few days ago there were some posts regarding which server to use to
> synch time and I tried the NASA server. Worked fine, except it was
> nearly two minutes off from one of those "atomic clocks" I keep near the
> computer desk. I know it's not atomic, it picks up a radio signal from
> the U.S. defense system. But still, two minutes is a large degree of
> latitude of accuracy. But just now, 5AM here, I just checked the two
> together again, and they only disagree by about 8 seconds. I don't have
> a question I guess, unless you know an explanation for this.


They know you're watching.

--
Dogpoop

Stand by me.
 
Reply With Quote
 
 
 
 
Whiskers
Guest
Posts: n/a
 
      08-23-2007
On 2007-08-23, Rgr <(E-Mail Removed)> wrote:
> A few days ago there were some posts regarding which server to use to
> synch time and I tried the NASA server. Worked fine, except it was
> nearly two minutes off from one of those "atomic clocks" I keep near the
> computer desk. I know it's not atomic, it picks up a radio signal from
> the U.S. defense system. But still, two minutes is a large degree of
> latitude of accuracy. But just now, 5AM here, I just checked the two
> together again, and they only disagree by about 8 seconds. I don't have
> a question I guess, unless you know an explanation for this.


Unscrupulous factory owners used to push the factory clock forwards in the
morning and then set it to run slow during the working day, so as to
squeeze more work out of the workers without paying extra. Workers were
of course forbidden to own clocks or watches of their own.

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~
 
Reply With Quote
 
Mike Easter
Guest
Posts: n/a
 
      08-23-2007
Rgr wrote:
> A few days ago there were some posts regarding which server to use to
> synch time and I tried the NASA server. Worked fine, except it was
> nearly two minutes off from one of those "atomic clocks" I keep near
> the computer desk. I know it's not atomic, it picks up a radio signal
> from the U.S. defense system. But still, two minutes is a large
> degree of latitude of accuracy. But just now, 5AM here, I just
> checked the two together again, and they only disagree by about 8
> seconds. I don't have a question I guess, unless you know an
> explanation for this.


Long story with a bottom line. Scoot to the end if all you want is my
theory.

I have an 'atomic clock' which has an additional function of giving me
an outside temperature reading.

In order to do its outside temperature reporting, it has to be within
'range' of the outside temperature sensor/transmitter. When it can't
get that temperature radio signal, the outside temperature reading is
'blanked'. But the time display doesn't work like that.

On my atomic clock, it expects to be able to access the time information
from the satellite in the eastern sky when it is best received at the
early hours of the morning before dawn, so it needs to have an
'unobstructed' radio frequency portal to that sky for time adjustments.
But the time display shows the time all the time, whether the clock has
received a signal recently or not. But there is a difference in the
display regarding recent time setting update.

When the signal has been 'synched' within the last 24 hours, there is a
little beacon displayed. When the signal has not been synched recently,
the beacon doesn't display. Sometimes I have to temporarily move the
clock to give it a eastern sky window exposure so that it can get its
signal to set its time appropriately. There is another or 3rd type
display which shows the beacon icon blinking instead of absent or
present. That is when it is 'wanting' the radio signal.

I also have a NIST time client on my computer. The utility can be
configured for which server to use and whether or not to 'fudge' some
fractions of a second for any delay of the signal to me. When my NIST
time is set and my atomic clock is set they are not anything like 8
seconds difference. They are 'exactly' the same time.

I suspect that your atomic clock is not getting its signal regularly and
maybe it doesn't have a display to tell you that it isn't.

--
Mike Easter

 
Reply With Quote
 
=?ISO-8859-15?Q?R=F4g=EAr?=
Guest
Posts: n/a
 
      08-23-2007
Whiskers wrote:
> On 2007-08-23, Rgr <(E-Mail Removed)> wrote:
>> A few days ago there were some posts regarding which server to use to
>> synch time and I tried the NASA server. Worked fine, except it was
>> nearly two minutes off from one of those "atomic clocks" I keep near the
>> computer desk. I know it's not atomic, it picks up a radio signal from
>> the U.S. defense system. But still, two minutes is a large degree of
>> latitude of accuracy. But just now, 5AM here, I just checked the two
>> together again, and they only disagree by about 8 seconds. I don't have
>> a question I guess, unless you know an explanation for this.

>
> Unscrupulous factory owners used to push the factory clock forwards in the
> morning and then set it to run slow during the working day, so as to
> squeeze more work out of the workers without paying extra. Workers were
> of course forbidden to own clocks or watches of their own.


I think I used to work for one of them. I was making tennis shoes in
China at the time.
 
Reply With Quote
 
Whiskers
Guest
Posts: n/a
 
      08-23-2007
On 2007-08-23, Mike Easter <(E-Mail Removed)> wrote:

[...]

> On my atomic clock, it expects to be able to access the time information
> from the satellite in the eastern sky when it is best received at the
> early hours of the morning before dawn, so it needs to have an
> 'unobstructed' radio frequency portal to that sky for time adjustments.
> But the time display shows the time all the time, whether the clock has
> received a signal recently or not.


My 'radio controlled' clock uses a terrestrial long-wave time service (the
British one), and checks once an hour. Europe is well covered by such
signals, but for other parts of the world I can see that using eg the GPS
satellites would be more practical.

> But there is a difference in the
> display regarding recent time setting update.


That's a feature my radio-controlled clock lacks - but it does have a
'reset' button which sets the hands to 1200 and then gets a new
time-check.

I also have a radio-controlled wrist-watch that tunes in once a day to a
long-wave signal from Germany; that does have a means of confirming
whether or not it has managed to get a time-check recently.

(Both were made by Junghans).

It's fun to watch the hands whizzing round when the clocks go forward or
back )

[...]

--
-- ^^^^^^^^^^
-- Whiskers
-- ~~~~~~~~~~
 
Reply With Quote
 
Mike Easter
Guest
Posts: n/a
 
      08-23-2007
Whiskers wrote:
> Mike Easter


>> On my atomic clock, it expects to be able to access the time
>> information from the satellite in the eastern sky


Due to your comments I doublechecekd. On further research, it turns out
this is 'a lie' -- ie I was wrong/mistaken about what I was receiving
from in the eastern sky. See below. <in each instance, what follows
the link was snipped from the article there>

>> when it is best
>> received at the early hours of the morning before dawn, so it needs
>> to have an 'unobstructed' radio frequency portal to that sky for
>> time adjustments.


That part is correct. The best radio transmission is 'in the dark' --
when it is dark at both the source of the radio signal and the source of
the receiver. The radio signal is actually WWVB being broadcast from
Fort Collins, CO US.

http://en.wikipedia.org/wiki/WWVB WWVB is a special NIST time signal
radio station near Fort Collins, Colorado, co-located with WWV. WWVB is
the station that radio-controlled clocks throughout North America use to
synchronize themselves. The signal transmitted from WWVB is a continuous
60 kHz carrier wave, derived from a set of atomic clocks located at the
transmitter site. [...] There are two identical antennas [...] used to
radiate the WWVB signal. Both antennas are 122 meters tall, and their
centers are separated by 857 meters.

> My 'radio controlled' clock uses a terrestrial long-wave time service
> (the British one), and checks once an hour. Europe is well covered
> by such signals, but for other parts of the world I can see that
> using eg the GPS satellites would be more practical.


I didn't realize before now that y'all did that differently.
http://en.wikipedia.org/wiki/Atomic_clock Atomic clock -- Radio
clocks - There are a number of longwave radio transmitters around the
world - in particular DCF77 (Germany), HPG (Switzerland), JJY (Japan),
NPL or MSF (United Kingdom), TDF (France), WWVB (United States). Many
other countries can receive these signals (JJY can sometimes be received
even in Western Australia and Tasmania at night), but it depends on time
of day and atmospheric conditions. There is also a transit delay of
approximately 1 ms for every 300 km the receiver is from the
transmitter. When operating properly and when correctly synchronized,
better brands of radio clocks are normally accurate to the second.

> I also have a radio-controlled wrist-watch that tunes in once a day
> to a long-wave signal from Germany; that does have a means of
> confirming whether or not it has managed to get a time-check recently.


I set my digital wristwatch manually to a second periodically from the
NIST from the computer or from the 'atomic' radio clock. Also, when I'm
adjusting the minute hand and winding my pendulum clock I 'think about'
how much different timekeeping was in the days of the pendulum clocks
compared to the days of NIST clients and atomic radio clocks/watches.

> It's fun to watch the hands whizzing round when the clocks go forward
> or back )


Heh.

--
Mike Easter

 
Reply With Quote
 
Stickems.
Guest
Posts: n/a
 
      08-23-2007
Your atomic clock is correct. The NASA server is slow due to it having to
pass the signal through the Internet. If you were to compare, as I have
done, the time signals received with the BBC news on the radio and on the
Internet you will find that there is a delay of about 14 seconds on the
Internet. This delay varies, I suppose, according to how busy the Internet
is.


"Rgr" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
|A few days ago there were some posts regarding which server to use to
| synch time and I tried the NASA server. Worked fine, except it was
| nearly two minutes off from one of those "atomic clocks" I keep near the
| computer desk. I know it's not atomic, it picks up a radio signal from
| the U.S. defense system. But still, two minutes is a large degree of
| latitude of accuracy. But just now, 5AM here, I just checked the two
| together again, and they only disagree by about 8 seconds. I don't have
| a question I guess, unless you know an explanation for this.


 
Reply With Quote
 
why?
Guest
Posts: n/a
 
      08-23-2007

On Thu, 23 Aug 2007 14:25:09 GMT, Stickems. wrote:

>Your atomic clock is correct. The NASA server is slow due to it having to
>pass the signal through the Internet. If you were to compare, as I have


I would hope any fairly good time sync software on the PC would take
care of that if the source is sending,

reference, originate and transmit time stamps.

>done, the time signals received with the BBC news on the radio and on the
>Internet you will find that there is a delay of about 14 seconds on the
>Internet. This delay varies, I suppose, according to how busy the Internet
>is.
>
>
>"Rgr" <(E-Mail Removed)> wrote in message
>news:QeGdnYcAvNFR0FDbnZ2dnUVZ_vGinZ2d@pghconnect. com...
>|A few days ago there were some posts regarding which server to use to
>| synch time and I tried the NASA server. Worked fine, except it was
>| nearly two minutes off from one of those "atomic clocks" I keep near the
>| computer desk. I know it's not atomic, it picks up a radio signal from
>| the U.S. defense system. But still, two minutes is a large degree of
>| latitude of accuracy. But just now, 5AM here, I just checked the two
>| together again, and they only disagree by about 8 seconds. I don't have
>| a question I guess, unless you know an explanation for this.
>


Me
 
Reply With Quote
 
Chris Syn
Guest
Posts: n/a
 
      08-23-2007
reformat and reinstall..opps

"Rgr" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
>A few days ago there were some posts regarding which server to use to synch
>time and I tried the NASA server. Worked fine, except it was nearly two
>minutes off from one of those "atomic clocks" I keep near the computer
>desk. I know it's not atomic, it picks up a radio signal from the U.S.
>defense system. But still, two minutes is a large degree of latitude of
>accuracy. But just now, 5AM here, I just checked the two together again,
>and they only disagree by about 8 seconds. I don't have a question I guess,
>unless you know an explanation for this.



 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Internet time synch failure Rod Speed Computer Information 18 05-25-2005 09:41 PM
Re: Internet time synch failure Colin Computer Support 1 05-25-2005 04:13 AM
Windows 2000 time synch on startup taco@bell.com.notvalid Computer Support 11 02-14-2005 07:46 PM
Palm synch with Outlook on TS Keyboard Cowboy MCSE 16 09-25-2004 02:15 PM
Palm synch with Outlook on TS eddi rox MCSE 3 09-23-2004 12:57 AM



Advertisments