On Fri, Nov 30, 2012 at 8:39 PM, David I. Emery wrote:
> On Fri, Nov 30, 2012 at 09:58:29PM -0500, Bob Camp wrote:
> > Hi
> >
>
> > The problem just the clock it's also the operating system. If it's not
> > designed with timing in mind (= it's an RTOS at some level) then you
> > will have sloppy t
On Fri, Nov 30, 2012 at 09:58:29PM -0500, Bob Camp wrote:
> Hi
>
> The problem just the clock it's also the operating system. If it's not
> designed with timing in mind (= it's an RTOS at some level) then you
> will have sloppy timing. Counters can help, but they are not the entire
> solution. If
saidj...@aol.com said:
> New JLT GPSDOs step back in 10 Steps over 10 seconds if more than 250ns off,
> then adjust the last ns slowly.
Thanks/interesting.
How/why did you pick 10?
> If within 250ns, they just slowly slew back.
How fast is "slowly"?
--
These are my opinions. I hate spam.
I just found an interesting new Symmetricom product
http://www.symmetricom.com/products/test-and-measurement/phase-noise-allan-deviation-test-sets/3120A-Phase-Noise-Test-Probe/
It looks familiar, doesn't it?
Adrian
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Hi
Typo…
Sorry
Bob
On Nov 30, 2012, at 9:49 PM, Bob Camp wrote:
> Hi
>
> A few more possibilities:
>
> 1) Slip the clock by one cycle per second rather than 10 at once.
> 2) Take the pps off of a 100 MHz source sync'd to the 10 MHz and slip by less
> than 100 ns per step
> 3) Take the pps
Hi
The problem just the clock it's also the operating system. If it's not designed
with timing in mind (= it's an RTOS at some level) then you will have sloppy
timing. Counters can help, but they are not the entire solution. If your email
(or anti-virus or ...) program can pop up and monopolize
Hi
A few more possibilities:
1) Slip the clock by one cycle per second rather than 10 at once.
2) Take the pps off of a 100 MHz source sync'd to the 10 MHz and slip by less
than 100 ns per step
3) Take the pps off of a DDS and fine tune the slip however slowly you might
wish.
In practice, the
Hal,
New JLT GPSDOs step back in 10 Steps over 10 seconds if more than 250ns off,
then adjust the last ns slowly.
If within 250ns, they just slowly slew back.
Bye,
Said
Sent From iPhone
On Nov 30, 2012, at 18:10, Hal Murray wrote:
>
> Does anybody know what happens in a TBolt or Z3801? (o
On Fri, Nov 30, 2012 at 04:24:38PM -0600, shali...@gmail.com wrote:
> I am not sure that a precision clock will help if the cpu is busy and skips
> clock cycles. I believe this is one of the problems with general purpose OSes
> like Windows.
>
> I believe the better boards like the Soekis use ha
There is some info here http://www.ursanav.com/ - click on the Latest LF
News on the right side.
There is a paper here
http://www.nautelnav.com/wp-content/uploads/2011/09/Nautel-UrsaNav-NAV10-Research-Paper.pdfthat
I think is relevant. It will take me some time to wade through it
with no guarante
Does anybody know what happens in a TBolt or Z3801? (or any other boxes?)
Suppose your system goes into holdover for long enough to be interesting.
Suppose for discussion that the clock drifts so that the PPS if off by a
mircosecond.
I can see two ways to recover. One is to jump the 10 MHz
Well as predicted they went home at 5pm. Signals off the air.
On Fri, Nov 30, 2012 at 7:26 PM, Bill Riches wrote:
> Nothing going on in Cape May for a while - I don't know if they are done
> testing.
>
> Bill WA2DVU
> Cape May, NJ
>
> -Original Message-
> From: time-nuts-boun...@febo.com
oops sorry that was supposed to be reply to sender not to list. Sorry sorry.
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On 11/30/2012 7:58 PM, John Ackermann N8UR wrote:
> On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR wrote:
>
>> In this case, you're not looking for the RTC but rather the clock that
>> drives the COU
>
> Read "CPU". Stupid iPad keyboard.
I use MessageEase on my android smartphone. The stan
On 11/30/2012 7:54 PM, John Ackermann N8UR wrote:
> On Nov 30, 2012, at 7:10 PM, Sarah White wrote:
>
>> On 11/30/2012 6:30 PM, Eric Garner wrote:
>>> the actual RTC on modern (Intel based) PC's is driven from a standard
>>> 32,768 Hz crystal attached to the PCH. some of them are in incredibly sm
On 11/30/12 4:58 PM, John Ackermann N8UR wrote:
On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR wrote:
In this case, you're not looking for the RTC but rather the clock that drives
the COU
Read "CPU". Stupid iPad keyboard.
I was wondering.. Clock Oscillator Unit? Cryptic Obfuscated Un
OK, I'll bite. Why?
Jim
>>>I've never done it using to the RTC crystal, but I do it quite
frequently in my Day Job to >>>Ethernet controllers on those same pc mother
boards.
>>>
>>>-Eric
On Fri, Nov 30, 2012 at 4:10 PM, Sarah White wrote:
> On 11/30/2012 6:30 PM, Eric Garner wrote:
> > the a
On Nov 30, 2012, at 7:42 PM, John Ackermann N8UR wrote:
> In this case, you're not looking for the RTC but rather the clock that drives
> the COU
Read "CPU". Stupid iPad keyboard.
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On Nov 30, 2012, at 7:10 PM, Sarah White wrote:
> On 11/30/2012 6:30 PM, Eric Garner wrote:
>> the actual RTC on modern (Intel based) PC's is driven from a standard
>> 32,768 Hz crystal attached to the PCH. some of them are in incredibly small
>> packages now instead of the old tuning fork-in-a-c
In this case, you're not looking for the RTC but rather the clock that drives
the COU, which is what drives the system clock. On most systems, the RTC is
read only at startup and is not used once the system is running.
John
On Nov 30, 2012, at 6:30 PM, Eric Garner wrote:
> the actual RTC on
Hi
In the case of the Soekris, it was not the real time clock that we all played
with. THe clock you fiddle is the CPU clock. The system is running FreeBSD or
Lunix, so it's a cut above a typical embedded system. A RTOS (like Windows CE)
will indeed do a bit better with a good CPU clock. Anythi
Nothing going on in Cape May for a while - I don't know if they are done
testing.
Bill WA2DVU
Cape May, NJ
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Mike Garvey
Sent: Friday, November 30, 2012 3:25 PM
To: 'Discussion of precise ti
I've never done it using to the RTC crystal, but I do it quite frequently
in my Day Job to Ethernet controllers on those same pc mother boards.
-Eric
On Fri, Nov 30, 2012 at 4:10 PM, Sarah White wrote:
> On 11/30/2012 6:30 PM, Eric Garner wrote:
> > the actual RTC on modern (Intel based) PC's
On 11/30/2012 6:30 PM, Eric Garner wrote:
> the actual RTC on modern (Intel based) PC's is driven from a standard
> 32,768 Hz crystal attached to the PCH. some of them are in incredibly small
> packages now instead of the old tuning fork-in-a-can ones. peeling off the
> load caps and crystal from t
the actual RTC on modern (Intel based) PC's is driven from a standard
32,768 Hz crystal attached to the PCH. some of them are in incredibly small
packages now instead of the old tuning fork-in-a-can ones. peeling off the
load caps and crystal from the board would allow you plenty of spaces to
tack
It all depends on what clock your talking about. Any given PC probably has more
than one oscillator onboard.
Generally there will be one for the CPU, one for the display circuitry, and
probably one for the real time clock.
Presuming you are talking about the CPU clock, it should be fairly
strai
I am not sure that a precision clock will help if the cpu is busy and skips
clock cycles. I believe this is one of the problems with general purpose OSes
like Windows.
I believe the better boards like the Soekis use hardware dividers to alleviate
the cpu busy problem.
Didier
Sent from my Droi
Hi
It's most commonly done with things like a Soekris 45xx series board. You don't
need anything very exotic for the frequency conversion. The jitter in the PC is
way worse than what the external chips will be creating.
The real question is - what is the "magic frequency" on the particular mot
Has anyone ever used a TAPR clock block or other frequency synthesizer
to sort the clock drift / timing problems on a regular computer? I'll
probably end up with a used dell or IBM workstation for this purpose.
Recently, I came across a low-cost frequency synthesizer capable of
using a 10mhz frequ
Hello to the group.
Its been working very fine all day long. I am using two austron 2100 series
rcvrs. One is comparing the loran c sig to a hp3801 gps system and the
other the house reference a RB.
I expect the signal to go off the air most likely about 5pm. This is a 9-5
bunch after all.
Some of
IF, and it's a big IF, it is compatible with existing LORAC-C receivers,
it would be a most welcome development, and would mitigate to some extent
the idiotic decision to shut down LORAN-C.
If it's incompatible with the existing, installed receivers, because it
uses some kind of proprietary, sole
Maybe a patent search is in order.
- Original Message -
From: "Mike Garvey"
To: "'Discussion of precise time and frequency measurement'"
Sent: Friday, November 30, 2012 3:24 PM
Subject: Re: [time-nuts] Loran
Might be these guys; this abstract is from the Precision Time and Time
I
Might be these guys; this abstract is from the Precision Time and Time
Interval (PTTI) Meeting which took place in Reston, VA during this past
week.
There will be a follow-up manuscript.
Mike
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Be
Hi Nigel,
Connect did have some recently by this came from another? seller who is from
the same town. WoodsGroup are also selling them (item 390489973647 ) but at
excessive prices and without the antenna. The GPS mod seems to replace the PLL
board and loops the LF signal through. The GPS antenna
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