[Elecraft] Mac Clock Question

[Detrick Merz]

Unfortunately, with some recently releases of OSX, Apple decided to tweak
the NTP daemon to "save battery power." This results in the clock drifting
significantly from our perspective, but "not enough for the average user to
care about." It can definitely be enough for JT modes to care about. I
tracked my clock accuracy at one point on OSX 10.9 (I think), and as I
recall I saw it drift up to 20 seconds at some points in time.

I'm unsure if it's been improved in the most recent macOS releases, but the
idea of forcing a restart of NTP either daily, or whenever you fire up
WSJT-X, hasn't necessarily been as much of a faux pas as one might think.

-detrick
K4IZ

On Tue, Feb 20, 2018 at 12:49 PM, Dale Chayes <dale at ldeo.columbia.edu>
wrote:

>
> > On Feb 20, 2018, at 12:06 , Walter Underwood <wunder at wunderwood.org>
> wrote:
> >
> > Should not need to unlock and relock daily. In fact, that could hurt
> time synchronization.
>
> Indeed, restarting runs the risk of loosing  (over-writing) the
> calibration (local clock drift rate) that NTP uses to keep the local clock
> accurate.
>
> From my experience, I would put the idea of “restart every day” in the
> same category as old guidance about primitive operating systems that some
> folks used to recommend re-booting every day in order to prevent crashes.
>
> > Mac OS runs NTP, which continually adjusts the time.
>
>  I _think_ every modern OS uses an NTP implementation or at least has one
> available.
>
> Some light:
> https://en.wikipedia.org/wiki/Network_Time_Protocol <
> https://en.wikipedia.org/wiki/Network_Time_Protocol>
> and not so light:
> http://www.ntp.org/ <http://www.ntp.org/>
> https://www.eecis.udel.edu/~mills/papers.html <
> https://www.eecis.udel.edu/~mills/papers.html>
> reading for those who don’t know about NTP.
>
>
> I’d be interested to hear about ones that:
> a) don’t have an NTP implementation available and/or
> b) have one that does not work reliably
>
> One issue I’d keep an eye on is whether your OS (and it’s NTP daemon) will
> tell you if it’s having trouble syncing.
>
> With a good NTP implementation, you could go months (or years) with no
> significant time of day error and then loose your time sync and slowly
> drift off to the point that it matters for your application.
>
> You can also run into this problem if you are off the ‘net and the NTP
> daemon can’t get to the NTP source often enough.
>
> -Dale
>
> >
> > wunder
> > K6WRU
> > Walter Underwood
> > CM87wj
> > http://observer.wunderwood.org/ (my blog)
> >
> >> On Feb 20, 2018, at 8:55 AM, John Stengrevics <jstengrevics at comcast.net>
> wrote:
> >>
> >> Richard,
> >>
> >> I run a Mac here.  Go to System Preferences, Unlock, enter “
> us.pool.ntp.org <http://us.pool.ntp.org/>”, Lock and you will be good to
> go.
> >>
> >> You should Unlock, delete, and renter the above daily to make sure you
> are synched - takes 30 seconds.
> >>
> >> John
> >> WA1EAZ
> >>
> >>> On Feb 20, 2018, at 11:49 AM, Richard <FlatHat at comcast.net> wrote:
> >>>
> >>> Before I get into the list of problems I’m having using WSJT-X FT8 on
> my K3S, I’d like to know:
> >>>
> >>> 1. Is the automatic clock setting in my Mac mini (running Sierra,
> 10.12) good enough for modes like JT65 and FT8?
> >>>
> >>> 2. If not, what’s a good reliable time sync app I can download and use?
> >>>
> >>> Cheers!
> >>>
> >>> Richard Kunc — W4KBX
> >>>
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