[Elecraft] OT setting your computer to NIST

[David Woolley]

Whilst Windows is not good for accurate time synchronisation using any 
tool, the current versions of w32time, the native Windows NTP support, 
can be configured 
<https://technet.microsoft.com/en-us/library/cc773263%28v=ws.10%29.aspx#w2k3tr_times_tools_uhlp> 
to be much better than the out of the box configuration.  In particular 
you must make sure that you specify servers without the special poll 
interval flag.

t can be set to behave pretty much like the reference implementation of 
version 3 NTP.  Windows ports of the reference implementation of version 
4 NTP software, that the servers you use are likely to be using, are 
available at no charge, and, for example, Meinberg supply a free 
installer for it.  Whilst another branch of this thread (not yet on the 
digest) tends to perpetuate the misunderstanding that this was written 
by Meinberg, that is not true.  It is actually the open source reference 
implementation, as used on many and available for all Linux systems (but 
with some build options set for Windows).  Meinberg have simply added a 
Windows installer.

Properly tuned I'd expect 95 percentile accuracy as about 20ms with 
w32time, maybe 10ms with the reference implementation and better than 
1ms with Linux.

Out of the box w32time polls at very long intervals (7 days for 
standalone installations) and is designed to keep the time accurate to 
within the few seconds needed for Kerberos authentication on Windows 
networks, but the current software can be tuned for poll rates of 
seconds, use multiple servers and interpolate with frequency compensation.

The continued existence of software like Dimenion 4 and Tardis owes more 
to marketing than to being better solutions.  (Microsoft are not 
interested in Windows client systems being used outside of a Windows 
network, so don't advertise the full capabilities of w32time.)

Incidentally, the primary author of the NTP protocol specification and 
its reference implementation is W3HCF.

-- 
David Woolley
Owner K2 06123

On 26/06/15 22:22, Josh Fiden wrote:
> Most 6m EME guys I know are using Dimension 4. Works great and in my
> experience MUCH more accurate than the built-in Windows time sync.