Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-12 Thread Rob Kimberley 
Hi Martin,

Thanks for this.

Rob

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Martin Burnicki
Sent: 11 October 2017 18:17
To: time-nuts@febo.com
Subject: Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather 
GPS time

Hi Rob,

Rob Kimberley wrote:> I'm using the Meinberg NTP Distribution here with their 
NTP Monitor prog on Win10-64, and two GPS NTP servers.> > Config
settings: -> >server 192.168.1.120 iburst minpoll 4 maxpoll 5>
server 192.168.1.121 iburst minpoll 4 maxpoll 5> > Consistent sub millisecond 
results. I've also found that Win10 actually performs way better than Win7.
This is because with Windows 8 and newer there is a new API call to read the 
system time with 100 ns resolution. The older API provides only 1 ms resolution.

ntpd uses the new API, if available.

Martin
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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-12 Thread Tom Van Baak 
>> These days the speaker is almost the last usable interface for this.
>
> ….. and the mic input is one of the few inputs left to feed “events” into.

Yes, and by connecting the speaker to the mic and issuing a pulse through the 
speaker you can estimate the latency of the OS. It should act like an echo 
chamber and the number of echoes per second is your inverse latency.

The other trick is to use a TIC to compare the output pulse(s) against your 
house GPS/1PPS. You then compare the timestamp that the OS thought it was with 
the real UTC+TIC timestamp. Similarly, put a GPS/1PPS into the mic and compare 
the time the OS thinks it saw the pulse.

The results of these should give a nice pair of UTC offset and jitter plots. If 
at the same time you also measure the XO directly you can then subtract and 
pinpoint how much of the error is due to the XO and how much is due to OS 
design. For extra credit put NTP into the mix and see how badly NTP s/w 
performs compared to what a h/w solution could so.

/tvb

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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-12 Thread Bob kb8tq 
Hi

> On Oct 12, 2017, at 5:11 AM, Poul-Henning Kamp  wrote:
> 
> 
> In message 
> ,
>  Mark Sims
> writes:
> 
>> The next release of Heather has an audible tick clock mode where
>> it ticks at hh:mm:ss.000  This can be used to set your watch more
>> accurately, etc.
> 
> Consider the potential for people to attach wires to the PC-speaker
> as a means to get an electrical signal also.
> 
> These days the speaker is almost the last usable interface for this.

….. and the mic input is one of the few inputs left to feed “events” into.

Bob

> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-12 Thread Chris Wilson 
Hello time-nuts folk,


Thanks  for  all  the replies, I see now that it is nothing to concern
myself  with, and my curiosity is satisfied, much appreciated, you are
true  time  experts!  :)  Good  to  see  Lady  Heather continues to be
updated, thanks Mark.

on 12/10/2017 12:36  you wrote:


> Lady Heather's screen clock ticks when the time message comes in
> (which can be offset from the actual time in the message).  Heather
> applies a receiver type dependent adjustment to the time in the
> message and then displays the time.  If you enable the digital
> millisecond clock you will see that the clock does not necessarily tick at 
> hh:mm:ss.000

> The next release of Heather has an audible tick clock mode where it
> ticks at hh:mm:ss.000  This can be used to set your watch more accurately, 
> etc.

>  
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> and follow the instructions there.





-- 
   Best Regards,
   Chris Wilson.

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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-12 Thread Poul-Henning Kamp 

In message 
,
 Mark Sims
 writes:

>The next release of Heather has an audible tick clock mode where
>it ticks at hh:mm:ss.000  This can be used to set your watch more
>accurately, etc.

Consider the potential for people to attach wires to the PC-speaker
as a means to get an electrical signal also.

These days the speaker is almost the last usable interface for this.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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[time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Mark Sims 
Lady Heather's screen clock ticks when the time message comes in (which can be 
offset from the actual time in the message).  Heather applies a receiver type 
dependent adjustment to the time in the message and then displays the time.  If 
you enable the digital millisecond clock you will see that the clock does not 
necessarily tick at hh:mm:ss.000  

The next release of Heather has an audible tick clock mode where it ticks at 
hh:mm:ss.000  This can be used to set your watch more accurately, etc.

 
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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Martin Burnicki 
Hi Rob,

Rob Kimberley wrote:> I'm using the Meinberg NTP Distribution here with
their NTP Monitor prog on Win10-64, and two GPS NTP servers.> > Config
settings: -> >server 192.168.1.120 iburst minpoll 4 maxpoll 5>
server 192.168.1.121 iburst minpoll 4 maxpoll 5> > Consistent sub
millisecond results. I've also found that Win10 actually performs way
better than Win7.
This is because with Windows 8 and newer there is a new API call to read
the system time with 100 ns resolution. The older API provides only 1 ms
resolution.

ntpd uses the new API, if available.

Martin
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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Chris Wilson 
Hello,

According  to  that clock LH is lagging about 0.5 seconds behind... PC
time  matches it exactly, as close as the eye can tell. Thanks for the
replies.

on 11/10/2017 17:11  you wrote:


> For those who are in Europe there is the PTB (Physikalisch-Technische
> Bundesanstalt, the German Federal institute of Physics and Technology)
> service to check the PC's time:
> 






-- 
   Best Regards,
   Chris Wilson.

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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Azelio Boriani 
For those who are in Europe there is the PTB (Physikalisch-Technische
Bundesanstalt, the German Federal institute of Physics and Technology)
service to check the PC's time:


On Wed, Oct 11, 2017 at 5:25 PM, Mike Cook  wrote:
> I have Win7-64 and my LH and system time are the same (with a very short 
> delta of < 0.2s probably due to their respective window update time).
> I use the Meinberg disturb of NTP. My client’s offset from the paris 
> observatory is less than a millisec.
>
> Maybe you should check your NTP status and see what offset you get from a 
> known good source with ntpdate -b -d .
>
>
>
>
>> Le 11 oct. 2017 à 13:29, Chris Wilson  a écrit :
>>
>>
>>
>>  11/10/2017 12:24
>>
>> Probably   a   simple  answer,  but I am curious as to why my PC clock
>> which  is set by NTP on Windows 7 64 bit OS is ahead of Lady Heather's
>> time,  locked  to  a  Trimble  Thunderbolt  by  about  half  a  second
>> (guesstimate..)  I  caught  a screen shot of the discrepancy just now,
>> it's at http://www.gatesgarth.com/time.jpg
>>
>> I use NTP for low signal WSPR transmissions and a second out isn't the
>> end  of  the  world,  if  indeed  something  IS out. More academic than
>> problematic, thanks
>>
>> --
>>   Best Regards,
>>   Chris Wilson.
>> mailto: ch...@chriswilson.tv
>>
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>> time-nuts mailing list -- time-nuts@febo.com
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>> and follow the instructions there.
>
> "The power of accurate observation is commonly called cynicism by those who 
> have not got it. »
> George Bernard Shaw
>
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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Rob Kimberley 
I'm using the Meinberg NTP Distribution here with their NTP Monitor prog on 
Win10-64, and two GPS NTP servers.

Config settings: -

   server 192.168.1.120 iburst minpoll 4 maxpoll 5
   server 192.168.1.121 iburst minpoll 4 maxpoll 5

Consistent sub millisecond results. I've also found that Win10 actually 
performs way better than Win7.

Rob

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Mike Cook
Sent: 11 October 2017 16:26
To: Chris Wilson; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather 
GPS time

I have Win7-64 and my LH and system time are the same (with a very short delta 
of < 0.2s probably due to their respective window update time).
I use the Meinberg disturb of NTP. My client’s offset from the paris 
observatory is less than a millisec.

Maybe you should check your NTP status and see what offset you get from a known 
good source with ntpdate -b -d .




> Le 11 oct. 2017 à 13:29, Chris Wilson <ch...@chriswilson.tv> a écrit :
> 
> 
> 
>  11/10/2017 12:24
> 
> Probably   a   simple  answer,  but I am curious as to why my PC clock
> which  is set by NTP on Windows 7 64 bit OS is ahead of Lady Heather's 
> time,  locked  to  a  Trimble  Thunderbolt  by  about  half  a  second
> (guesstimate..)  I  caught  a screen shot of the discrepancy just now, 
> it's at http://www.gatesgarth.com/time.jpg
> 
> I use NTP for low signal WSPR transmissions and a second out isn't the 
> end  of  the  world,  if  indeed  something  IS out. More academic 
> than problematic, thanks
> 
> -- 
>   Best Regards,
>   Chris Wilson.
> mailto: ch...@chriswilson.tv
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

"The power of accurate observation is commonly called cynicism by those who 
have not got it. » George Bernard Shaw

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Re: [time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Mike Cook 
I have Win7-64 and my LH and system time are the same (with a very short delta 
of < 0.2s probably due to their respective window update time).
I use the Meinberg disturb of NTP. My client’s offset from the paris 
observatory is less than a millisec.

Maybe you should check your NTP status and see what offset you get from a known 
good source with ntpdate -b -d .




> Le 11 oct. 2017 à 13:29, Chris Wilson  a écrit :
> 
> 
> 
>  11/10/2017 12:24
> 
> Probably   a   simple  answer,  but I am curious as to why my PC clock
> which  is set by NTP on Windows 7 64 bit OS is ahead of Lady Heather's
> time,  locked  to  a  Trimble  Thunderbolt  by  about  half  a  second
> (guesstimate..)  I  caught  a screen shot of the discrepancy just now,
> it's at http://www.gatesgarth.com/time.jpg
> 
> I use NTP for low signal WSPR transmissions and a second out isn't the
> end  of  the  world,  if  indeed  something  IS out. More academic than
> problematic, thanks
> 
> -- 
>   Best Regards,
>   Chris Wilson.
> mailto: ch...@chriswilson.tv
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

"The power of accurate observation is commonly called cynicism by those who 
have not got it. »
George Bernard Shaw

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[time-nuts] NTP linked PC clock is slightly ahead of Lady Heather GPS time

2017-10-11 Thread Chris Wilson 


  11/10/2017 12:24

Probably   a   simple  answer,  but I am curious as to why my PC clock
which  is set by NTP on Windows 7 64 bit OS is ahead of Lady Heather's
time,  locked  to  a  Trimble  Thunderbolt  by  about  half  a  second
(guesstimate..)  I  caught  a screen shot of the discrepancy just now,
it's at http://www.gatesgarth.com/time.jpg

I use NTP for low signal WSPR transmissions and a second out isn't the
end  of  the  world,  if  indeed  something  IS out. More academic than
problematic, thanks

-- 
   Best Regards,
   Chris Wilson.
mailto: ch...@chriswilson.tv

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