[ntp:questions] Re: Trimble's Acutime 2000 compared to Arcron MSF

Paul Croome Paul.Croome at softwareag.com
Thu Sep 25 09:30:05 UTC 2003

ryandrk at hotmail.com (Drk Ryan) wrote in message news:<de98eac0.0309121148.2e954ed3 at posting.google.com>...
> Are there ratings available for different reference clocks performance
> with NTP?
> I am looking at the offset for two stratum-1 servers, one uses
> Trimble's Acutime 2000 and the other an Arcron MSF Receiver.
> The performance is much better with the Trimble receiver. Has anyone
> else experienced this? Or is there a problem with the MSF receiver?


Yes, some refclocks have better performance with NTP, others have
worse performance...

What exactly do you mean by performance? Does the ability of the U.S.
government to switch off GPS enter the equation? Or the fact that the
MSF transmitter is regularly switched off for maintenance? Do you need
to calibrate to absolute time? Do you mean long-term accuracy or short-term

Do you have a PPS interrupt signal available? 

The precision of the PPS signal from the Acutime claims to be 50ns (1 sigma);
you might expect an LF timecode receiver to be precise to a few milliseconds.
The LF receivers that I'm using seem to quantise their PPS output to 1ms.
Yes of course GPS is much more precise then MSF, doesn't everybody know that?

Much of this stuff is already available in the doc....


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