[ntp:questions] ntp-4.2.6p5 on Win 7 x64

David Taylor david-taylor at blueyonder.co.uk.invalid
Tue Jul 15 14:04:10 UTC 2014

On 15/07/2014 12:07, Nick wrote:
> This machine dual boots Mint 17 x64 and Win 7 SP1 x64.
> I have set the hardware clock to UTC.
> Mint 17 and Win 7 run on local time.
> I need reasonable time sync for WSJTX < 1 second.
> On Mint 17 ntp from the repo works well with offsets in the low
> tens of milliseconds, sometimes < 10ms.
> On Win 7 I have installed ntp-4.2.6p5 at spider-man-2-win32-setup.exe.
> This does not seem to work properly.
> The jitter and offset 'diverge'...
> These are not the worst offsets I've seen; 3 seconds is not unusual.
> Restarting the service 'fixes' it for a few minutes, then it all begins to
> 'diverge' again.
> Using the default ntp.conf except for "pool uk.pool.ntp.org iburst".
> What have I missed?


Some odd thoughts which may help....

You will find some advice on using NTP with Windows here:


I suggest installing /outside/ the C:\Program Files\ tree so that 
editing the .conf file and NTP writing its drift file is not virtualised.

Watch that the drift file is not repeatedly approaching its +/- 500 
(part per million limit).  If it is, I have suggestions in the notes above.

There are improvements in development versions of NTP, so you may want 
to try the current version:


There have also been reports that setting max poll = 7 may be required 
for best stability:

   pool uk.pool.ntp.org iburst  maxpoll 7

I am surprised you are getting servers from .ca when requesting a UK 
pool, but perhaps the display is truncated.  I would suggest adding a 
known-good UK server, perhaps:


On my own WIn-7/64 system I do run a GPS/PPS device (a Sure Electronics 
board) which gives results to within 100 microseconds:


but I've even used these directly connected to a COM port (for the PPS 
signal) and to a USB port for power:


That should keep you "perfectly" in time for your application.

David GM8ARV
Web: http://www.satsignal.eu

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