Le 27 juil. 2013 à 03:18, Julien Ridoux a écrit :
snip
Hi Mike,
Thanks for the interest in the data. You are quite right for everything
regarding data structure, but let me explain what we meant by that comment.
Timespec{} is a 64 bit data structure and support nanoseconds. Yes.
wd6...@gmail.com said:
Maybe low-profile rs232?
Something like: http://www.cablestogo.com/product/52138
Neat. Thanks.
I think that's referring to a different dimension.
I'm interesting in the thickness of the connector. If you measure a typical
connector, it's
0.65 thick
1.3 wide,
Thanks for that James.
Le 27 juil. 2013 à 04:26, James Peroulas a écrit :
Date: Fri, 26 Jul 2013 12:27:50 +0200
From: mike cook mc235...@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Subject: Re: [time-nuts] NTP to discipline Raspberry Pi
It seems you can't rely on the human backup. The UK Marine accident
Investigation Branch Has recorded numerous accidents due to poor lookout. See
http://www.maib.gov.uk/cms_resources.cfm?file=/KarinSchepersReportWeb.pdf
http://www.maib.gov.uk/cms_resources.cfm?file=/CoastalIsle.pdf
If you know your LORAN has a 1/4 mile accuracy then you stay 1/2 mile
away from bad things.
The trouble with GPS is that it is so good, people don't use common
sense and give obstacles a wide berth.
Brian
On 7/27/2013 04:21, Jim Lux wrote:
On 7/26/13 8:45 PM, J. Forster wrote:
I gather
There are other timing issues involved too.
Many radios still use relays to switch from transmit to receive. (PIN
diodes only in the more expensive ones). The radio receives a key
closure but delays RF output from 8 to 20 ms or more to allow time for
relay closure. This time delay becomes
I have seen the same problem in the Fluke 5700A and 5720A calibrators on the
bottom board quite often and they do not run that hot and are usually in a lab
enviroment.
Thomas Knox
To: time-nuts@febo.com
From: hmur...@megapathdsl.net
Date: Fri, 26 Jul 2013 19:22:10 -0700
Subject: Re:
About 25 years ago, I bought a bunch of LORAN-C receiver boards at the
Appelco bankrupcy auction. Despite zero doc, I got a couple running.
They had to 8085 uPs, one to compute the TDs and a second,on a daughter
board, to compute Lat/Long. The unit would repeatably hit my location w/in
a couple
Hal,
I like your term automagically. Typo or intentional, it describes
how most people 'understand' technology.
Mike
On 7/26/2013 8:07 PM, Hal Murray wrote:
ma...@non-stop.com.au said:
It you can figure out how to raise DTR while your application has the port
open it can be a good
Key here is how does the captain know that GPS is no longer providing an
accurate fix? You need 2 or more independent systems to cross check each
other.
Sent from my iPhone
On Jul 27, 2013, at 12:21 AM, Jim Lux jim...@earthlink.net wrote:
On 7/26/13 8:45 PM, J. Forster wrote:
I gather
As a (former) Naval Officer, I will tell you that a competent mariner
should always be using and cross-checking /all /sources -- GPS, radar,
dead reconing, /looking out the window/, and even celestial in open ocean.
(I frequently had to remind my junior officers that nobody ever ran
aground
People screw up. Period. The Costa Concordia, that Talgo train driver in
Spain, pilots fly into the ground as in San Francisco, just to name a few.
IMO, putting all one's eggs in the GPS basket is simply foolish,
especially when a continuous cross-check with an independant nav system
can be
I have seen a lot of differing opinions on GPS Spoofing and using back up
systems on this thread. Most pretty good, but a couple off the mark a bit.
Here are a couple of comments on GPS Spoofing.
- There are anti-spoofing GPS receivers available - to authorized
users. Typically DOD. Most,
Quite right Bob, Echolink is one such program that doesn't automagically raise
DTR when the port is opened.
Anyway, I have gone Echo-IRLP now, much more robust running under unix.
But I veer of topic..
--marki
-Original Message-
From: time-nuts-boun...@febo.com
Hi
Which is why the regulations (air or sea) *require* you to be using at least
two nav systems to check each other. If you are depending on only one system,
your breaking the rules. It's not a matter of weather there are 100,000 systems
available or not. It's a matter of weather they follow
What is the failure rate? The number of failures does not matter unless
we know the total number of attempts.
Do 1% of the ships that leave a harbor to become involved in an accident or
is it more like one in one ten million?
I'd bet there are tens of thousands of cases of GPS failures where
The failure rate does not matter a whole lot, if you or a loved one are
killed or injured.
How much comfort is it to a victim, if 1 person, or 5 million people,
survived ?
Failure rates only really matter to actuaries and insurance companies.
-John
=
What is the failure
Hi
Also to the same point - which system is more reliable? You can ask the people
who now use GPS how it compares in failure rate to what they used before. I
know what kind of answers I get when I ask those questions ….
Bob
On Jul 27, 2013, at 1:10 PM, Chris Albertson
And engineers.
Tom Holmes, N8ZM
Tipp City, OH
EM79
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J.
Forster
Sent: Saturday, July 27, 2013 1:21 PM
To: Discussion of precise time and frequency measurement
Subject: Re:
Key
Problem with GPS is its easy to spoof on one level and have a complete denial
of service on the other. Out in California a while back a malfunctioning TV
distribution amplifier jammed a major harbor and surrounding almost 25 sq miles
affected all because of a 49.95 TV amp had a problem.
When Cape Cod LORAN was functional, I could easily see the pulses with a
few turn coil maybe a foot in diameter, roughly resonated, and a scope.
-John
==
Key
Problem with GPS is its easy to spoof on one level and have a complete
denial of service on the other. Out in California a
My Tymeter just clacked over to 50 minutes after, and I had a sudden vision of
GPS locking its input to 60 Hz, like in the good old days when the power
companies cared about frequency. =) Has anyone actually gone that far in
their time-madness?
Bob - AE6RV
Hi
Loran can / could easily be jammed over a limited area, just like GPS. Nothing
crazy large or expensive would be required. The same sort of malfunctioning
this or that took out Loran from time to time over harbor sized areas. Loran
had so many issues with dropping out, that they simply were
Hi,
Anyone know where I can get firmware 1.13.0 or greater for the Trimble Acutime
gold?
--marki
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the
http://leapsecond.com/pages/atomic-nixie/ shows a KVARZ CH1-75 Active
Hydrogen Maser (5 MHz) through a HP 3325B synthesizer (60 Hz) through a HP
6827A bipolar power supply (100 VAC) to generate a 60 Hz mains.
At http://leapsecond.com/pages/mains/ he also shows the 60Hz grid
meandering forward and
LORAN was/is not perfect geographic features could and did limit reception
However an effective jammer would need effective power in the hundred watt
range and a efficient antenna system plus a connection to power grid or small
Genset.
Not amenable to easy concealment and fairly easy to DF
Hi
If you go back into the Frequency Control Symposium papers from the 1980's
there are several of them from the power line people on using GPS to track 60
Hz. They have kept at it ever since. Their main interest is in tracking phase
across a large network, rather than locking up generators
Hi
A Loran jammer would / could work with a *much* smaller antenna if a local area
was the target. Power is easy at 100 KHz. Loran is no easier / harder to DF
than GPS.
Bob
On Jul 27, 2013, at 3:37 PM, Scott McGrath scmcgr...@gmail.com wrote:
LORAN was/is not perfect geographic features
But wouldn't it be easier to set phase if they had a known, good frequency?
Oh. Frequency isn't the issue, is it? If you have to supply to the west coast
for a few hours and then plug into the east coast to purchase power, you might
have to do a large phase shift between the two. And after
That's one big Pocket Watch
HI HI
73, Dick, W1KSZ
On 7/27/2013 12:11 PM, Tim Shoppa wrote:
http://leapsecond.com/pages/atomic-nixie/ shows a KVARZ CH1-75 Active
Hydrogen Maser (5 MHz) through a HP 3325B synthesizer (60 Hz) through a HP
6827A bipolar power supply (100 VAC) to generate a 60 Hz
Hi
The guys who put up the original papers were from Quebec Hydro. Their issue was
trying to set things up independent of the grid and dispatch power to where
ever it was needed. Once they demonstrated it was possible a lot of other
people became interested. Oddly enough at dinner I brought up
The guys who put up the original papers were from Quebec Hydro. Their issue
was trying to set things up independent of the grid and dispatch power to
where ever it was needed. Once they demonstrated it was possible a lot of
other people became interested. Oddly enough at dinner I brought up
The Jupiter (TU-30) board in my homebrew GPSDO has died.
A friend gave me some unmarked Jupiter-like boards with Conexant chips
that he had been told were Jupiter compatible.
The boards are mounted on an aluminium plate that has a puck-type
antenna on it. One of the chips has a sticker with
The old time (stone age) method of setting the phase of a power generator
was easy: Get an ordinary light bulb and connect it between the grid and
your generator, Adjust the phase of your generator until the bulb goes
dim. When the bulb is 100% dead out then flip the switch and connect the
Hi
Apparently if you are generating hydro station type levels and sending it out
over long distance lines, the EMI is pretty fierce. They tried various LF and
HF solutions and could not get a good enough signal to be useful.
Bob
On Jul 27, 2013, at 6:38 PM, Hal Murray hmur...@megapathdsl.net
https://plus.google.com/u/0/photos/111617808980322733757/albums/5890266601277045697
The board with the edge connector was inside the same bag the
connector was in, the bag was taped to the unit.
I pulled the ends off first, but was immediately stopped with foam, it is
glued in place.
Then when I
Greetings,
Actually it requires TWO light bulbs in series (or one bulb with a twice the
voltage rating). They usually use TWO standard bulbs in series for EACH
phase line. This gives an immediate indication that the phase rotation is
correct.
I have actually seen it done about 12 years ago to
Hi
It turns out that if you have a network with a *lot* of sources and a *lot* of
loads and a *lot* of interconnects, you would need a *large lot* of light
bulbs….
Bob
On Jul 27, 2013, at 9:32 PM, Gordon Batey gpba...@wildblue.net wrote:
Greetings,
Actually it requires TWO light bulbs
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