I Might be seeing the same thing you (Ulrich, Ernie, Brooks) are seeing,
although I would not attribute it to WAAS or EGNOS, as I am not using a
receiver that is enabled for differential corrections.
I am using the 1 pulse-per-second output from a Motorola M12+ Timing
receiver (M12+T) to disipl
Geoff Powell said the following on 04/23/2006 05:42 PM:
> Is PPS kernel discipline compiled into the default FreeBSD kernel?
No, but it's a pretty easy thing to turn on -- you add a line to the
config file and tell it to go. Pretty straightforward, *once* you find
the instructions.
>
>
>>I am
Geoff Powell wrote:
> In article <[EMAIL PROTECTED]>, John Pettitt
> <[EMAIL PROTECTED]> writes
>
>> I'll second the soekris box - my box time.no-such-agency.net is a 4801
>> running FreeBSD with a GPS18LVC.You can expect offsets in the +/-
>> 5us range except when the box is stressed - the
In article <[EMAIL PROTECTED]>, John Pettitt
<[EMAIL PROTECTED]> writes
>I'll second the soekris box - my box time.no-such-agency.net is a 4801
>running FreeBSD with a GPS18LVC.You can expect offsets in the +/-
>5us range except when the box is stressed - the standard xtal in the box
>is not te
Geoff Powell wrote:
>
>
>> And - most OSes should do the trick. FreeBSD has a really nice
>> precision timekeeping interface, though -- and it makes a marvelously
>> solid time server. I'm running it on a few Net4801s and recommend
>> it. You can very easily build an image for it using
In article <[EMAIL PROTECTED]>, David
Andersen <[EMAIL PROTECTED]> writes
>You'll get more than you expect -- the offset you're observing on
>ADSL is very likely wrong, because the delays your packets experience
>on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't
>actually believ
In article <[EMAIL PROTECTED]>, John Ackermann N8UR
<[EMAIL PROTECTED]> writes
>FreeBSD is definitely the best tuned OS for NTP timekeeping, but Linux
>can do OK. The biggest problem is that there's no kernel support for
>PPS signals in the 2.6 series of kernels. There is a patch available
>for a
David Andersen wrote:
> You'll get more than you expect -- the offset you're observing on ADSL
> is very likely wrong, because the delays your packets experience on
> adsl aren't symmetric. NTP assumes symmetry. So I wouldn't actually
> believe that a 1ms offset is really 1ms off, depending on th
You'll get more than you expect -- the offset you're observing on
ADSL is very likely wrong, because the delays your packets experience
on adsl aren't symmetric. NTP assumes symmetry. So I wouldn't
actually believe that a 1ms offset is really 1ms off, depending on
the RTT to your ISP.
B
John Ackermann N8UR said the following on 04/23/2006 05:02 PM:
> First, as a point of reference the HP 5087A distribution amp is spec'd
> at 5MHz to have phase noise less than -145dBc(1 Hz) >1kHz from the
> carrier.
>
> We did our tests at 10MHz, so the results are precisely comparable --
Geoff Powell said the following on 04/23/2006 05:00 PM:
> So my question is - should I continue with Debian Stable, or would
> OpenBSD be better for sub-microsecond accuracy? Indeed, is sub-
> microsecond offset achievable with this hardware? GPSDOs and Rb or Cs
> standards are not yet practical p
I've just started getting interested in precision timekeeping - if you
can call an offset from UTC that is measured in units of milliseconds
"precision".
My current timeserver is a Buffalo Linkstation, patched to run Debian
Stable, and slaved via 2MBit ADSL to my ISPs Stratum 2 timeserver, using
I had a chance today to take a TADD-1 and one of the Spectracom 8140T
amplifier modules over to a friend who has an HP 3048 phase noise
measurement system. We got some very encouraging results.
First, as a point of reference the HP 5087A distribution amp is spec'd
at 5MHz to have phase noise less
Brooks,
i live in Germany abt. 500 km north of Franfurt/M and i run a M12+ in
continuous duty in my GPSDO. Normally i do not keep track of the
receiver's pps. However, on April 23 15:00 UTC i have started to record
the phase relationship as measured inside my GPSDO. Will be glad to
assist you and
Not directly related to timekeeping but most metrology labs (used to)
have a Dranetz 606 Line Disturbance Analyzer sitting over in the
corner monitoring power quality.
I have several of these and need to fix one. I'm looking for a copy
of the service/calibration manual. And a full user's manual
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