albertson.ch...@gmail.com said:
> But I use a set of five different servers all controlled by different
> organizations and they are geographically distributed. Also some of these
> are randomly elected "pool" servers. So even I don't know who I will ask
> for time. How could anyone corrupt a
On 10/05/2016 01:17 AM, Chris Albertson wrote:
All that said, there is money to be made by spoofing time. If I can fool
a stock broker into accepting trades minutes late I could be rich.
Minutes? I thought the proper unit for that is nanoseconds :).
-Ruslan
The current system is very secure. The paper is correct in the most users
don't bother with authentication or encryption. I don't.But let's say
some one tried to spoof me into thinking it is three seconds later then it
really is by some how setting up an NTP server that gives me incorrect
tim
On Tue, Oct 4, 2016 at 6:52 PM, Bob Camp wrote:
> Hi
>
> If:
>
> 1) You are a typical Ham in a home environment
> 2) All the servers are “out there” on the internet
> 3) You have any of the normal modems feeding your home
>
> You have a very basic issue in terms of path delay. All the servers you
I just learned about this from a public post:
https://roughtime.googlesource.com/roughtime/
Not precise enough for us nuts, but intended to be secure.
(I wonder how it handles leap seconds? Too soon? :-) Actually, it
smears.)
-christopher.
de AI6KG
_
On Tue, Oct 4, 2016 at 9:05 PM, Chris Albertson
wrote:
> The problem, I think with your Internet sync's NTP servers is you are only
> using one server S. The most common practice is to use 3 to 5 with 5 being
> about the right number. If you get Ntp enough Internet servers to work
> with it ca
Hi
If:
1) You are a typical Ham in a home environment
2) All the servers are “out there” on the internet
3) You have any of the normal modems feeding your home
You have a very basic issue in terms of path delay. All the servers you can
access
have the *same* asymmetric delay. In that case, no
The problem, I think with your Internet sync's NTP servers is you are only
using one server S. The most common practice is to use 3 to 5 with 5 being
about the right number. If you get Ntp enough Internet servers to work
with it can detect problem like asymmetric path lengths which I'm sure is
y
On Tue, 4 Oct 2016 15:41:58 +1100
Larry Hower wrote:
> Ultimately we want sub-millisecond accuracy.
If you want to go that way, you will have to leave windows as
this operating system does not offer the facilities to get down
to such a low levelUnless you calibrate the whole path by injectin
Thank you all for the inputs. In the present case, the location is my home
about an hour north of San Francisco, California. We are in a rural
location with other homes and some small businesses (legal or otherwise).
There could be many things hung on the 60 Hz power lines adding noise to
the "sign
Lady Heather has support for setting the system clock from the GPS receiver.
The next release has support for analyzing and compensating for the GPS /
system / com port message delay. It does not use the 1PPS signal.
It can get the Windoze clock to under 40 msecs (two times the typical Wind
I think to sum up what has been written
1) USB connection will not work well for timing
2) Notebook computers dont work well for timing
3) A good NTP server on your LAN can get you "close" to what you need even
on PC notebooks
4) With effort and a real serial port and after downloading a copy of N
On 10/4/2016 6:41 AM, Larry Hower wrote:
> Hello to the List:
Hi and welcome!
> After a long and bitter struggle with XP and WIN 10, I am writing to ask
> for some help in solving some problems we have been having in our attempt
> to establish a very accurate time reference for use in EME activit
Suggest you try the following which I use on Win10 with great success
https://www.meinbergglobal.com/english/sw/ntp.htm#ntp_stable
and
https://www.meinbergglobal.com/english/sw/ntp-server-monitor.htm
Rob K
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Beha
Hi Larry,
You are using a bunch of h/w and s/w together and you want each piece to
maintain precise time.
Would it be possible for you to inject a very short GPS 1PPS pulse or GHz tone
into your antenna feed?
That will cause a slight blip in your raw data which your processing s/w can
then us
On 10/4/16 6:26 AM, Graham / KE9H wrote:
Larry:
You have multiple problems, with the way you are trying to define
"time-error."
I think you are defining it as the time error of the signal coming out of
your receivers/decoders.
You are blending all the error/delay sources together, and you need
Hello Larry,
for Windows i know only one piece of software that is able to set the system
clock within a few milliseconds. Dimension4.
http://www.thinkman.com/dimension4/features.htm
Since I have not yet even measured it i can not tell if it meets your
specifications.
Maybe you give it a try.
From: Graham / KE9H
Larry:
[]
First, the reflector has already jumped in and helped you with the
definition of absolute time. You can get single digit millisecond accuracy
(with some caviats and bewares) from NTP, for stations at different
locations. You should be able to get single digit micro
Considering some signal generators will have 1% (-40dBc) distortion with a
5k - 10k price tag, your 1% is not to bad.
On Mon, Oct 3, 2016 at 8:52 PM, Jeremy Nichols wrote:
> As an experiment, I bought an AIMS sine-wave inverter for the 105B Quartz
> Oscillator. The inverter has a built-in trans
Larry:
You have multiple problems, with the way you are trying to define
"time-error."
I think you are defining it as the time error of the signal coming out of
your receivers/decoders.
You are blending all the error/delay sources together, and you need to
break them apart, since each one will h
Hi
As others have mentioned, you have two strikes against you:
1) Modern laptops *love* power saving. That makes them poor time keepers
at the millisecond level. It takes some well thought out software in the OS to
keep track of all the strange things they do.
2) Windows XP is getting a bit o
Hi
A lot of the distortion on the AC line is locally produced. Consider a very
normal
bridge rectifier running into a capacitor. It draws “all” the current in narrow
spikes
near the peaks of the sine wave. A half wave rectifier would be even worse
(only
one spike per cycle). That highly non-li
Maybe living on other "countries" ? :)
When you live at the end of the power line, at many km from the last low
voltage transformator and when the lines are over-loaded, their distributed
inductance + their distributed capacitance [?] make the voltage hump to
"sleep". It's rising front is longe
Maybe a capacitive load in your facility ? Whenever I've looked at it - it's
always been pretty clean. For years we used the AC mains for time keeping - but
have found in some locations - especially ones with lots of dimmers - zero
crossing counting was ineffective. My feeling was that dimmers t
What's being transmitted?
If it's a repetitive message would it be possible to inhibit transmission
using an external time source, perhaps a PIC or even a Pi inhibiting the
"PTT", leaving the windows box in control of what's transmitted or do the
Windows boxes have to communicate with each other v
Jeremy wrote:
The result was about 5%
distortion for the inverter and 1.5% for the AC line. This got me to
wondering, we've discussed the AC power line frequency at length but not
other "qualities" of that "signal.' I was surprised that the AC line had
so much distortion but it's a subject I've
From: Hal Murray
david-tay...@blueyonder.co.uk said:
You can use a GPS puck or equivalent with PPS output to get the sort of
accuracy you need. ..:
PPS output is only half the battle. You also have to get it into the system
that needs it.
A modem control signal on an old fashioned serial po
You can find some information here :
https://www.meinberg.de/download/burnicki/time_synchronization_accuracy_with_ntp.pdf
Please note the resolution of the system time in Win XP is only about 16 ms.
The NTP service tries to extrapolate the system time to yield better
resolution, but applications
david-tay...@blueyonder.co.uk said:
> You can use a GPS puck or equivalent with PPS output to get the sort of
> accuracy you need. ..:
PPS output is only half the battle. You also have to get it into the system
that needs it.
A modem control signal on an old fashioned serial port (not USB) i
On Mon, Oct 3, 2016 at 9:41 PM, Larry Hower wrote:
>
>
> 1. We are using desktops and laptops in separate locations running XP or
> Win 10.
>
Assuming you have decent GPS receivers with an un-obstructed view of the
sky with 1 pulse per second output and you have let the GPS run long enough
to tr
Hello to the List:
After a long and bitter struggle with XP and WIN 10, I am writing to ask
for some help in solving some problems we have been having in our attempt
to establish a very accurate time reference for use in EME activities.
We are hoping to achieve less than 5ms deviation, although
Yes,
I did intensive measurements of power line quality. If the voltage THD of your
AC line is only 1.5%, then your area is supplied by vry good quality
energy.
Mine exceeds 10% :(.
Not only the THD as number is important, for certain applications the shape is
important, too [how you got
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