Such slewing solutions are OK for Google. They wouldn't work well for
one of the systems I work with, which uses system time to calculate
the position of a LEO satellite for purpose of pointing a 7.6 meter
X-band dish. Half a second of error corresponds to a pointing error
of 0.5 degrees, well
Stephane,
On 01/09/2015 12:53 PM, steph.rey wrote:
Dear all,
I'm trying to measure Alan Deviations using Timelab and some frequency
counters.
The device under test is a GPSDO using a TCXO as référence
I've an HP58503B GPSDO which feeds my counters. I've tried an HP5342A,
0-18 GHz, 1 Hz
Hello and Happy new year to all list members.
I have four questions regarding a Datum PRS-50:
1 - Is it similar to another Datum Cesium like the FTS 4060 or another
FTS series Cesium ?
2 - Is there a list of commands and the data the with get out of the
RS-232 port, which port (front or
Hi
If your only instrument is a counter.
— and —
You never measure past 1x10^-10 with that counter
— and —
Measurements that bounce around with a standard deviation of the difference
between readings of 1x10^-10 are ok.
— then —
No, you don’t need anything better than a 1x10^-10 ADEV.
Hi Tom dividing down wasn't always necessary I have sample from the UK GPO
Crystal Factory of NT-cut bars, quartz tuning fork, and Gapped Ring
crystals, the latter marked 400cps (pre Hertz :-)) ) I think these are
post WWII because they are mounted in IO base GT style tube envelopes.
yes, Ulrich's [ Rohde ] Father made a high precision clock around 1940,
which had an electronically tuned mechanical oscillator. The vibrating
400Hz tuning fork is phase locked to a quartz crystal oscillator, that
was the most precise clock at that time, and it worked as I have seen
it at
t...@patoka.org said:
1s/24h = 1/86400 which is approximately 12ppm. That means that Aging Offset
could slow down my clock for 1 second if I'll apply the maximum value one
day ahead (roughly). I need to do some experiments first. ;-) Its looks too
unreliable for me.
If you do it that
Hi Bob,
Many thanks for your prompt and detailled answer.
My question on applications wasn't on good ADEV where I perfetcly
understand the need, but actually what could be the applications of
measuring BAD ADEV (10e-7). That was my point asking what king of
application can we cover by
On 1/9/15 7:42 AM, steph.rey wrote:
Hi Bob,
Many thanks for your prompt and detailled answer.
My question on applications wasn't on good ADEV where I perfetcly
understand the need, but actually what could be the applications of
measuring BAD ADEV (10e-7). That was my point asking what king of
In message df7c7705-b1cc-4b8d-8bac-d471e2ab5...@bardagjy.com, Andy Bardagjy w
rites:
Does anyone know any other history about that particular piece of equipment?
I seriously doubt those claims of precision.
At datamuseum.dk we did a small booklet about the history of paper tape
as a
Andy,
Yes, Neal Stephenson's Mother Earth Mother Board article is a classic that
every time nut should read at some point.
The one page version is at
http://archive.wired.com/wired/archive/4.12/ffglass_pr.html
Prior to quartz, pendulum clocks and tuning fork oscillators were the standard.
Tom Van Baak wrote:
I couldn't help noticing that Debian just issued an update
to tzone, so that means Linux systems now know about the
leap second.
-Chuck Harris
Hi Chuck,
Linux systems now know about the leap second -- this is a very
dangerous assumption. And one reason why leap seconds
Reading about leap seconds for the past two days, I found that common
solution for it - just encode leap second event proactively and wait
for it.
Of course that possible only if device has that option. For example,
BC637PCI has a menu item 7. Program Leap Event Seconds. Which I did.
Now,
From a fascinating (albeit long) article about transatlantic communication
cables
http://archive.wired.com/wired/archive/4.12/ffglass.html
On the bottom of page 45 to the top of page 46
Each piece of equipment on this tabletop is built around a motor that turns
over at the same precise
On Fri, Jan 9, 2015 at 3:21 PM, Martin Burnicki
martin.burni...@burnicki.net wrote:
Systems which are simply time clients can receive the leap second warning
via the usual protocols like NTP or PTP/IEEE1588.
Indeed, they can. Even when there hasn't been a leap-second.
Practically all internet
This is an issue indeed. Here is what I get from MySQL Data Base support
site:
Before MySQL 5.0.74, if the operating system is configured to return
leap seconds from OS time calls or if the MySQL server uses a time zone
definition that has leap seconds, functions such as NOW() could return
d0ct0r wrote:
Reading about leap seconds for the past two days, I found that common
solution for it - just encode leap second event proactively and wait
for it.
Of course that possible only if device has that option. For example,
BC637PCI has a menu item 7. Program Leap Event Seconds. Which I
Gregory Maxwell wrote:
On Fri, Jan 9, 2015 at 3:21 PM, Martin Burnicki
martin.burni...@burnicki.net wrote:
Systems which are simply time clients can receive the leap second warning
via the usual protocols like NTP or PTP/IEEE1588.
Indeed, they can. Even when there hasn't been a leap-second.
Correct me if I'm wrong, but as I understand it the tzfile in the
tzone package is not used to update the system time - that relies on
NTP or similar. Rather, the leap second info in the tzone files is
made available for applications to use, primarily for calculating time
differences in the past.
Dear all,
I'm trying to measure Alan Deviations using Timelab and some frequency
counters.
The device under test is a GPSDO using a TCXO as référence
I've an HP58503B GPSDO which feeds my counters. I've tried an HP5342A,
0-18 GHz, 1 Hz resolution and a Philipps PM6654C, 0.01Hz resolution.
I couldn't help noticing that Debian just issued an update
to tzone, so that means Linux systems now know about the
leap second.
-Chuck Harris
Hi Chuck,
Linux systems now know about the leap second -- this is a very dangerous
assumption. And one reason why leap seconds have gotten out of
Hi
Welcome to the world of trying to measure this stuff …
On Jan 9, 2015, at 6:53 AM, steph.rey steph@wanadoo.fr wrote:
Dear all,
I'm trying to measure Alan Deviations using Timelab and some frequency
counters.
The device under test is a GPSDO using a TCXO as référence
I've an
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