The referenced article indicates that they apply the smear to their NTP
servers and allow
the clients to track the servers. This approach would place some limits
on the minimum
lead time you would need to implement the smear.
1) you would have to start early enough for the servers to detect
I've often wondered why more systems don't use TAI or other similar time scales
as their time source. If needed the time displayed to end users or third
parties could be converted to UTC just prior to presentation or transmittal.
For example a financial system that needs to time stamp
Martin,
[]
4) The television monitor ideas are an easy solution. Use a PC or Raspberry
Pi. One example here:
https://www.youtube.com/watch?v=vBQ3uqMep58
/tvb
=
.. and a Raspberry Pi clock with source code you could easily modify:
martin.burni...@burnicki.net said:
So I think they smeared it over more than just a few minutes. I'd expect
some hours, so standard NTP clients would just notify this as clock drift
(oscillator frequency offset) which they'd have to compensate. Since ntpd's
control loop is pretty slow it
Hello all.
I am planning to do some experiments to evaluate the aging of oscillators
(this one of the reasons I'm willing to buy the Milleren without EFC).
What I would like to do exactly is to sample the total of a counter (of
suitable number of bits, taking in account the fact that it will
Hi all,
This is my first post to the list. I have a Raspberry Pi B+ and a HAB Supplies
U-Blox Max-M8Q set in stationary mode connected to a Virgin Media Superhub
(broadband router) by a 0.5m cat7 ethernet cable. The GPS is attached to the
Pi's GPIO and has an external active antenna placed on
Hallo Stan
Anyone have any thoughts on exactly where to put a temperature sensor
for a proportional fan controller?
I have some fans having a thermistor built in -like shown in
http://img.techpowerup.org/091114/1114091748.jpg.
Seems to me to be a good enough place.
Rises the next question
Hi,
I just stumbled over this [1] nice article by Fritz Riehle that might be
of interest to others as well.
Attila Kinali
[1] Towards a Re-definition of the Second Based on Optical Atomic Clocks,
by Fritz Riehle, 2015
http://arxiv.org/abs/1501.02068
--
It is upon moral
On Mon, 12 Jan 2015 13:34:03 +0100
Attila Kinali att...@kinali.ch wrote:
I just stumbled over this [1] nice article by Fritz Riehle that might be
of interest to others as well.
And while we are at it:
2e-18 total uncertainty in an atomic clock,
by T.L. Nicholson et.al., 2015
Yes, you can get an Arduino R3 on eBay for $4 with shipping...
The GPIB connector will cost you more!
Didier KO4BB
On January 12, 2015 8:45:12 AM CST, paul swed paulsw...@gmail.com wrote:
That certainly is a hack. But its something I have often thought about
and
never did. He is right its
Yes, you can get an Arduino R3 on eBay for $4 with shipping...
The GPIB connector will cost you more!
Didier KO4BB
A sandwich of two PCB is about the same thickness as the center plug of a GPIB
male connector. So layout 2x12 pads to match the pins and you have a one-piece
Arduino and
Hi Tom,
You are correct, but it does not really matter because it will not be
instantaneous, and for a period of time that is well within the range of human
perception, the clock will be off by more than you would normally expect.
We have been talking about NTP being able to keep the time to
Hi
Actually it’s a bit worse than you might expect.
The uncorrected sawtooth will give you about 20 ns of wander. At the one day
level, GPS without some sort of ionosphere help (like a dual frequency
receiver) will add another 10 ns or so to that. Net, your pps is spread over a
30 ns range.
Every good time nut knows about the hazards and subtle wonders of unintentional
injection locking of oscillators. Other people apparently don't... How forced
injection locking of ring oscillators can be hazardous to your wallet:
Your antenna could be better. But really the bottle neck on any NTP
server is time stamping the PPS. There is greater uncertainty in the
time stamp then of the PPS. The best solution ever (I can't find the
link) was done using an external clock. It was a low power Intel PC
running BSD and the
Today, I did the check the settings for my BC637 card. I was surprised
that its overwrite my manual setting for the Leap Event by following
information:
Time Settings:
Mode : GPS
Time Format: Binary
Year : 1995
On Mon, Jan 12, 2015 at 6:45 AM, paul swed paulsw...@gmail.com wrote:
its really a one instrument interface as it doesn't
have the buffers to drive the load of multiple instruments.
But heavens that has to be a really cheap interface for a bit of soldering
effort. My type of effort. :-)
Ciao Andrea,
On Mon, 12 Jan 2015 11:59:26 +0100
Andrea Baldoni erm1ea...@ermione.com wrote:
The sampling interval could come from a (long time based on a) sawtooth
uncorrected PPS from a cheap GPS, a sawtooth corrected from a good one
(perhaps
the Lucent GPSDO), or a computer using NTP.
Hi all,
This is my first post to the list. I have a Raspberry Pi B+ and a HAB
Supplies U-Blox Max-M8Q set in stationary mode connected to a Virgin Media
Superhub (broadband router) by a 0.5m cat7 ethernet cable. The GPS is
attached to the Pi's GPIO and has an external active antenna placed on
Neil
Welcome to time-nuts. You say that your antenna is less then ideal. OK on
time-nuts your going to find out details matter. So what does that mean?
Typically the antenna needs to be high enough to have a clear view of the
sky and it does matter.
But there have been posts in the past about the
That certainly is a hack. But its something I have often thought about and
never did. He is right its really a one instrument interface as it doesn't
have the buffers to drive the load of multiple instruments.
But heavens that has to be a really cheap interface for a bit of soldering
effort. My
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