aph...@comcast.net said:
> Here is a powerpoint presentation arguing for e-loran:
> https://www.gps.gov/governance/advisory/meetings/2009-05/doherty.pdf
Thanks.
eLoran meets needs of all identified critical applications -- and others
-- 10-20 meter navigation accuracy for harbor entrance
--
Hi,
This is so not my area of interest but I did come across the
following quote from the link listed below.
"A backup system is also a possible element. The British have
demonstrated that eLoran can deliver time with 50 nanoseconds
accuracy or better “pretty much anywhere you want to,”
Alex
Funny you bring up the loop antenna. Thats definitely one of the answers I
ran across. Though I was trying to avoid the wire loop.
But that said actually what I need to drive can be quite a small loop so
maybe the right answer.
Along those lines I need to look at the driving Z. Sort of
by making a loop around the territory, on which you would like to
receive the signal, inside of that loop you will have a very decent
reception without using to high transmit power a 100' x 200' area could
be covered with 100mW, since the wave length of the used low
frequencies is multiple
Paul,
You really don't want to be building an antenna that radiates energy, which
is a far-field
concept. In your case, at 30 ft range, you're so far inside the near field
that all the
antenna articles in the world won't help, since they address radiating into
the far field.
That's what WWVB
As to eLORAN, you can deny positioning but maintain timing service simply by
modifying the GRI and since eLORAN is software based thats not a difficult
change.
Navigation receivers go into fail but timing receivers only need ONE station.
As the users of SRS700’s and Austrons do when
Gee, thats strange especially for those of us who ran the Austron comparitors
to check our local standards against the LORSTA’s
On Sep 6, 2018, at 8:04 PM, Bob kb8tq wrote:
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that
the vast majority
of these systems
Interestingly, Gregory just posted about his success with some FTDI
USB/RS-232 cables that are the real thing in a separate thread.
On Thu, Sep 6, 2018 at 7:03 PM Didier Juges wrote:
> Not sure what you refer to. I have made a large number of
> microcontroller-based Thunderbolt monitor kits and
Hi
No, eLoran *never* on it’s best day could ever deliver the kind of timing that
the vast majority
of these systems require. It simply is not and can not do the job. The world
has moved *way*
past the sort of timing it can actually deliver.
Bob
> On Sep 6, 2018, at 6:35 PM, Scott McGrath
Not sure what you refer to. I have made a large number of
microcontroller-based Thunderbolt monitor kits and they do not have that
issue.
In any event, a problem like this cannot be the fault of the Thunderbolt,
all it does is send data. It's up to the receiver to process it, including
properly
GPS.gov: Selective Availability
https://www.gps.gov/systems/gps/modernization/sa/
Sep 23, 2016 - The United States has no intent to ever use Selective
Availability again. In September 2007, the U.S. government announced
its decision to procure the future generation of GPS satellites,
known as
I'm sure this has been discussed many times here.
E-Loran - I designed the timing hardware that controlled the
transmitters for that upgrade while I was at Timing Solutions.
As I remember it, it was funded by the FAA to be a backup for GPS.
The FAA planned to make more use of GPS in the
On Thu, Sep 06, 2018 at 06:35:23PM -0400, Scott McGrath wrote:
> Actually we DID have a radio based system that provided sufficient accuracy
> it was called eLORAN but it was killed by US politicians because they did not
> want a much more inexpensive to operate system ???competing??? with GPS.
Working on the wwvb simulator and it works really well. On to the last
piece. Transmission over maybe 30 ft.
Ever notice everyone that makes a simulator has the clock on top?
Well thats because its pretty hard to get a 60 KHz signal actually out.
Even though I know loopsticks are not great
Actually we DID have a radio based system that provided sufficient accuracy it
was called eLORAN but it was killed by US politicians because they did not want
a much more inexpensive to operate system ‘competing’ with GPS.Shutting
down LORAN saved 32m dollars annually the NAVSTAR GPS
I read that the latest GPS sats don't even have the ability to implement
selective availability... seems a dubious claim to me, though.
-
> Indeed it might get turned back on again.
___
time-nuts mailing list --
Hi
Well, we *do* have experience with that. It was called selective availability.
Indeed it might get turned back on again. It’s impact on a properly designed
GPSDO - not much. It takes a bit longer to get to best stability. System time
wise, it still works “good enough”.
A four hour long
These are Samsung's version of the "UCCM" series of GPSDOs. Lady Heather now
works with them. I had to tweak the code to handle their funky/erratic
end-of-line sequences... various versions of CR/LF, LF, LF/CR. Their STATUS
screen and some message responses are also a bit different. They
Instead of relying on the PPS to time the start of the simulated WWVB
transmissions, I opted instead to rely on the Arduino timing functions and then
refresh the data and the start every five minutes. No WWVB clocks use the
signal continuously; generally they all copy the signal once a day.
Sadly, you'll need more than just a lump of Ferrite to stop 60kHz
escaping to the street via the power cables..
That, and you'll probably also find the home power circuit seriously
polluted anyway around 60kHz, as a result of all the "other stuff" you
have that uses small SMPS's, with little
I was able to sort out my issue with the DST bits with the help of the
code Andy Backus recently published. I believe my code should now be ready
for anyone who's curious to try out. Complete details are available on the
following page:
We just put up another GPS antenna for our backup thunderbolt, and now IT is
blaming that for why our wifi is sluggish.
And it happens whether the new antenna is even connected!
https://www.kb6nu.com/theyll-do-it-every-time/
I should have known.. (KC6ETE here)
And there is the other significant vulnerability since GPS is a MILITARY system
the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be
unavailable as well.
On Sep 6,
On Tue, 4 Sep 2018, 18:35 John Sloan, wrote:
> Folks:
>
>
>
> Yesterday (2018-09-03) afternoon (about 22:00UTC, 16:00MDT) I noticed one
> of my three home-made GPS-disciplined NTP servers had lost its GPS lock.
> After some forensics on my part, this (2018-09-04) morning (about 16:00UTC,
>
Folks:
Well blow me down. It took some Google Maps fu on the web on my part, but
my time and place does indeed coincide with this “GPS Interference Testing” at
White Sands Missile Range. I just happened to be in my home office watching
several of my GPS-disciplined NTP servers when this
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