[time-nuts] Need Time Help

David J Taylor david-taylor at blueyonder.co.uk
Tue Oct 4 03:01:51 EDT 2016

Hello to the List:

After a long and bitter struggle with XP and WIN 10, I am writing to ask
for some help in solving some problems we have been having in our attempt
to establish a very accurate time reference for use in EME activities.

We are hoping to achieve less than 5ms deviation, although anything below
15ms will be adequate for now.
I ask for advice on how we can use the above gear or other gear or other
software to have our setup deliver better than 15ms accuracy.

Ultimately we want sub-millisecond accuracy.

Any help will be very much appreciated.  Thanks in advance for anything you
can advise.


Larry Hower




You can use a GPS puck or equivalent with PPS output to get the sort of 
accuracy you need.  I've written up some notes here:


and you can see the results here for Windows 2000 and Windows-10 systems (I 
no longer have an XP system with GPS/PPS reference):


0.5 ms is easily achieved, although it's desirable to keep the systems 
running 24 x 7 (or started well in advance) and as constant a temperature as 
you can reasonably achieve helps.

If you want, you could also build or buy an external NTP reference based on 
GPS/PPS, such as a Raspberry Pi or the LeoNTP server, and then sync the PCs 
over the LAN or Wi-Fi, but the results won't be as good as a PPS input 
direct to the PC:


I haven't read your long post in detail, so I hope the above suits.

David GM8ARV
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor at blueyonder.co.uk
Twitter: @gm8arv 

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