[Elecraft] Mac Clock Question
Walter Underwood
wunder at wunderwood.org
Tue Feb 20 13:42:31 EST 2018
With a terminal window open, run “ntpq -p” to get a list of current NTP peers and the offset in milliseconds.
$ ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
+10.74.16.53 129.6.15.28 2 u 522 1024 377 25.148 -0.522 3.996
*10.74.16.54 128.138.141.172 2 u 794 1024 377 23.834 -2.152 0.769
Almost exactly 25 years ago, I wrote a more complicated NTP info script. At the time “groper” implied that it was groping around in the dark. Times have changed.
https://opensource.apple.com/source/ntp/ntp-92.30.1/scripts/ntp-groper.auto.html
wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)
> On Feb 20, 2018, at 10:23 AM, Detrick Merz <detrick at merzhaus.org> wrote:
>
> 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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>>
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