Richard B. Gilbert wrote:
Generally, those crystals have failed quality control by the clock/watch
makers.
We are not talking about the RTC crystal!
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On Wed, Feb 15, 2012 at 06:04, Garrett Wollman wrote:
> In article <4f39fd1a.6020...@c3energy.com>,
> Ron Frazier (NTP) wrote:
>
>>Perhaps a silly question, but, does the "tick" that drives the OS
>>software clock originate from the RTC or from the CPU master clock at 2
>>GHz or whatever? Just t
On 2/14/2012 2:54 AM, Chris Albertson wrote:
Perhaps a silly question, but, does the "tick" that drives the OS software
clock originate from the RTC or from the CPU master clock at 2 GHz or
whatever? Just trying to understand how this stuff works.
Look in the directory
/sys/devices/syste
In article <4f39fd1a.6020...@c3energy.com>,
Ron Frazier (NTP) wrote:
>Perhaps a silly question, but, does the "tick" that drives the OS
>software clock originate from the RTC or from the CPU master clock at 2
>GHz or whatever? Just trying to understand how this stuff works.
Customarily, there
On Wed, Feb 15, 2012 at 04:22, unruh wrote:
> On 2012-02-15, Richard B. Gilbert wrote:
>>
>> Four, five, and seven are the magic numbers for a robust configuration.
>> Most sites will settle for four. The very paranoid or the very rich
>> might go for seven.
>
> Four is horrible, in that two to
On 2012-02-15, Richard B. Gilbert wrote:
> On 2/14/2012 1:43 AM, David J Taylor wrote:
>> "A C" wrote in message
>> news:4f398579.9060...@acarver.net...
>> []
>>> I'm not sure it's a good idea either but I would really like to
>>> understand why a refclock clamps the polling interval at such a lo
On 2/14/2012 10:50 AM, Ron Frazier (NTP) wrote:
On 2/14/2012 9:36 AM, unruh wrote:
On 2012-02-14, Ron Frazier (NTP) wrote:
On 2/13/2012 3:25 PM, Chris Albertson wrote:
On Mon, Feb 13, 2012 at 10:59 AM, Chuck Swiger wrote:
Perhaps a silly question, but, does the "tick" that drives the OS
softw
On 2/14/2012 1:43 AM, David J Taylor wrote:
"A C" wrote in message
news:4f398579.9060...@acarver.net...
[]
I'm not sure it's a good idea either but I would really like to
understand why a refclock clamps the polling interval at such a low
value when nearly every bit of documentation says we sho
On 2012-02-14, Ron Frazier (NTP) wrote:
> Hi all,
>
> I have my USB GPS running pretty well. However, I have noticed a few
> occasions when it goes wonky. Those are:
>
> a) Sometimes it appears to produce more consistent loopstats charts
> running the process on Above Normal priority (in Windo
> Also, I'd like to know how to have multiple USB serial devices
> plugged in, since, as I understand it, there's no guarantee that the same
> USB device will always be assigned to /dev/ttyUSB0.
Simple hack is to edit less /etc/init.d/ntpd
Be sure and save the edited verion as an OS upgrade
Hi all,
This is the story of the hoops I had to jump through to get my USB GPS
to work with Ubuntu 11.04 and NPTD without using GPSD. When I first set
up the system, I couldn't get the GPS to work any way I tried. It turns
out that the AppArmor system was preventing it from working. Another
On Tue, Feb 14, 2012 at 11:25 AM, Ron Frazier (NTP)
wrote:
As has been suggested by others, I know
> I can get hugely better accuracy using a different GPS and PPS, and I plan
> to experiment with that when I get time and money. (I've been ignoring lots
> of other household things while pursuin
On Tue, Feb 14, 2012 at 11:53 AM, Ron Frazier (NTP)
wrote:
> Hi all,
>
> I have my USB GPS running pretty well. However, I have noticed a few
> occasions when it goes wonky. Those are:
>
> a) Sometimes it appears to produce more consistent loopstats charts running
> the process on Above Normal p
Ron Frazier (NTP) wrote:
> server nist1-ny.ustiming.org prefer minpoll 6 maxpoll 13
> server nist1.columbiacountyga.gov minpoll 6 maxpoll 13
> server utcnist.colorado.edu minpoll 6 maxpoll 13
> server nist1.aol-ca.truetime.com minpoll 6 maxpoll 13
Stratum 1 ser
On 2/14/2012 01:49, David Lord wrote:
A C wrote:
On 2/13/2012 15:44, David Lord wrote:
Recent ntpd is supposed to handle that level of frequency
offset but most of my pcs have had the frequency offset
adjusted to be < 10 ppm which is done when I build a kernel
with "options PPS_SYNC" and "opti
Hi all,
I have my USB GPS running pretty well. However, I have noticed a few
occasions when it goes wonky. Those are:
a) Sometimes it appears to produce more consistent loopstats charts
running the process on Above Normal priority (in Windows) rather than
RealTime priority. I have to do f
Hi all,
I have my USB GPS working pretty good at this point on both Windows and
Linux. I have some more Linux specific questions that I'll post later.
At the moment, I'm working on Windows. As has been suggested by others,
I know I can get hugely better accuracy using a different GPS and PP
Hi Paul,
I noticed the module you mentioned uses the Sirf III chipset. I've been
doing a good bit of experimentation with a GlobalSat BU-353 (no PPS)
which is also based on the same chipset. David Taylor was nice enough
to post my experience on his website from a series of dialogs we had.
On 2012-02-14, Ron Frazier (NTP) wrote:
> On 2/14/2012 9:36 AM, unruh wrote:
>> On 2012-02-14, Ron Frazier (NTP) wrote:
>>
>>> On 2/13/2012 3:25 PM, Chris Albertson wrote:
>>>
On Mon, Feb 13, 2012 at 10:59 AM, Chuck Swiger wrote:
>>> Perhaps a silly question, but, do
On Feb 13, 2012, at 10:20 PM, Ron Frazier (NTP) wrote:
> Perhaps a silly question, but, does the "tick" that drives the OS software
> clock originate from the RTC or from the CPU master clock at 2 GHz or
> whatever? Just trying to understand how this stuff works.
On classic IBM AT hardware, an
On 2/14/2012 9:36 AM, unruh wrote:
On 2012-02-14, Ron Frazier (NTP) wrote:
On 2/13/2012 3:25 PM, Chris Albertson wrote:
On Mon, Feb 13, 2012 at 10:59 AM, Chuck Swiger wrote:
Perhaps a silly question, but, does the "tick" that drives the OS
software clock originate from the
On 2012-02-14, Ron Frazier (NTP) wrote:
> On 2/13/2012 3:25 PM, Chris Albertson wrote:
>> On Mon, Feb 13, 2012 at 10:59 AM, Chuck Swiger wrote:
>
> Perhaps a silly question, but, does the "tick" that drives the OS
> software clock originate from the RTC or from the CPU master clock at 2
> GHz o
Figure I might chime in with the gps unit I got and if your in Aust i
think its probably about the best deals i've seen that has a pps line
(theres also another one they have if you can do smd soldering thats
cheaper again).
http://www.twig.com.au/store/product_info.php?products_id=108&osCsid=148a
A C wrote:
On 2/13/2012 15:44, David Lord wrote:
Recent ntpd is supposed to handle that level of frequency
offset but most of my pcs have had the frequency offset
adjusted to be < 10 ppm which is done when I build a kernel
with "options PPS_SYNC" and "options TIMER_FREQ=119".
This kernel
Richard B. Gilbert wrote:
On 2/13/2012 2:36 AM, Dave Hart wrote:
That's OCXO, oven controlled crystal oscillator. Why X for crystal?
Crystal is frequently abbreviated as XTAL. I think this usage may have
originated in amateur radio.
It did.
All radio were amateur radio in those days.
I.e.
Ron Frazier (NTP) wrote:
On 2/13/2012 3:25 PM, Chris Albertson wrote:
On Mon, Feb 13, 2012 at 10:59 AM, Chuck Swiger wrote:
You might be able to improve the stability of the crystal by
ensuring good
airflow and cooling via HVAC as needed. And I suppose you could
adjust the
rate by changi
David Woolley wrote:
Uwe Klein wrote:
semi OT ( either OnTopic or OffTopic ;-):
What happens if I kill ntpd during clock slewing ?
What happens if I SIGTERM ntpd during clock slewing ?
Linux implementations, at least, will retain frequency corrections in
kernel discipline mode and lose th
Ron Frazier (NTP) wrote:
Perhaps a silly question, but, does the "tick" that drives the OS
software clock originate from the RTC or from the CPU master clock at 2
GHz or whatever? Just trying to understand how this stuff works.
On "IBM PC" hardware it doesn't originate from the 32768 Hz RT
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