[time-nuts] leontp offset

[David J Taylor]

More followup:

I set up and configured a brand new xenial box using ntp, and let it run
for a day (approx 7 hours).  Here are the ntpq -p from that:

$ ntpq -p
     remote           refid      st t when poll reach   delay   offset
jitter
==============================================================================

*172.17.21.11    .GPS.            1 u  164  512  377    0.312   -1.531
0.325
+172.17.21.12    .GPS.            1 u   60  512  377    0.127   -1.137
0.502
x172.17.21.233   .GPS.            1 u   60   64  377    0.126    8.462
0.028
ntp.ubuntu.com  .POOL.          16 p    -   64    0    0.000    0.000
0.000
-tssnet1.tss.net 131.107.13.100   2 u   64  512  377   39.496   14.121
0.263
+srcf-ntp.stanfo .shm0.           1 u  139  256  377   61.998    6.312
0.265
-borris.netwurx. 204.9.54.119     2 u  130  256  377   83.512    9.359
0.361
-lithium.constan 18.26.4.105      2 u   22  512  377   98.791    9.172
0.709
-alphyn.canonica 132.246.11.231   2 u  247  512  377  110.436    8.303
1.354
-chilipepper.can 145.238.203.14   2 u   44  512  377  171.861   11.901
1.374

the .11 and .12 units are the Arbiters.  The .233 is the leontp unit.  This
is two days in a row, on two separate boxes (one a fresh install) that the
arbiters are showing up differently than the rough consensus of others.

As a side note, I really like these leontp units.  They are small and
simple and appear to do what they say very well.  'Leo' in the leontp has
been very responsive, over and above, to working with me on this issue,
even acquiring and poring over the Arbiter 1084C manual to find potential
settings that can introduce offsets.

I will not have a chance to explore some of these Arbiter settings until
next week.  Arbiters are something of a pain to configure.  Arbiter has
some new models in their pipeline that use a web based interface for
settings but those have been in the 'real soon now' stage for over a year.
_______________________________________________


Suggestion: use the configuration above except mark the two Arbiters as 
"noselect".  That way you can monitor them compared to the LeoNTP and the 
Internet servers.

I like Hal's idea of the wrong edge as the minimum pulse width is (likely) 
10 milliseconds.  "Pulse duration is programmable from 0.01 seconds to 600 
seconds, except in one-shot mode, where the output is Low prior to the 
specified time and High thereafter."

  http://www.arbiter.com/catalog/product/model-1093b-c-gps-satellite-controlled-precision-time-clock-500ns.php#tabs-2

Cheers,
David
-- 
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Email: david-taylor at blueyonder.co.uk
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