[time-nuts] Local System Time Sync

Chris Albertson albertson.chris at gmail.com
Wed Jul 26 00:23:15 EDT 2017

You should be using NTP for that.

Simply "syncing" the local clock to GPS is never the best thing to do.   If
you think about it 50% of the time the local clock would have to go
backwards and 50% forwards.  This means you could have the system time be
at the same time twice or you have missing time intervals.

The correct way is to adjust the RATE of the local clock so you never have
missing or double time.   This is exactly the same as building a GPSDO.
Every adjustment period you compare there PHASE of the local clock to GPS
then adjust the RATE if required.     NTP does this.

On Tue, Jul 25, 2017 at 7:45 PM, Lee - N2LEE via time-nuts <
time-nuts at febo.com> wrote:

> I have what I believe is a simply question. Especially for this
> illustrious brain trust. :)
> How can I force Lady Heather to time sync the local computer system it is
> interfaced to ?
> Isn’t this what the /ts[odhm] command accomplished or I am
> misunderstanding ?
> - Thunderbolt is interfaced to a Mac laptop running LH5
> - Connection is USB to Serial cable (might be the issue because of no PPS)
> - Turn off Internet NTP sync on laptop
> - Purposely set laptop time 15 seconds ahead
> - Enter / then after the dash(-) I enter tsm to sync system time every
> minute.
> I thought this would force the system to sync ever minute with Thunderbolt
> time.
> But it doesn’t it. It never corrects the laptop time, it is always wrong.
> What am I missing here ?
> Thanks,
> Lee
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Chris Albertson
Redondo Beach, California

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