In message 55371.12.6.201.2.1299648580.squir...@popaccts.quikus.com, J. Fors
ter writes:
in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference.
That makes the LORAN shutdown look even more idiotiuc!
Well, how can you argue with closing a system
p...@phk.freebsd.dk said:
The reason LORAN-C got killed was that DoD/DHS couldn't jam it if a
terrorist with a suitcase-nuke was trying to find his way to Congress.
Why can't they jam it?
It's just a matter of signal strength. If want to jam a small region, they
can use a local
In message 20110309082926.d5f9f800...@ip-64-139-1-69.sjc.megapath.net, Hal Mu
rray writes:
p...@phk.freebsd.dk said:
The reason LORAN-C got killed was that DoD/DHS couldn't jam it if a
terrorist with a suitcase-nuke was trying to find his way to Congress.
Why can't they jam it?
They can, All
El 09/03/2011 06:29, J. Forster escribió:
This is a surprise:
in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference.
This is a phallacy, except if we are taking into account indirect GPS
users, i.e. admitting that a credit card user is a GPS
In message 4d7740b8.2040...@hvsistemas.es, Javier Herrero writes:
El 09/03/2011 06:29, J. Forster escribi=F3:
This is a surprise:
in reality more than 90 percent of the users of GPS worldwide use it
primarily for a timing reference.
This is a phallacy, except if we are taking into account
H I wasn't impressed. The 'scope screen shot of noise levels on the
outputs used 20mV/division, and the thickness of the regulated traces told us
precisely nothing. Now if the author had measured 20uV noise over a BW of 10Hz
to 100kHz (about 63nV/rtHz), or 3uV over the same BW (about
If one can say that the actual noise-floor signal is approx. white noise
than the peak to average is a factor of 6 to 7 on a analog scope. I once
read this somewhere and found it not a so bad decision.
- Henry
--
ehydra.dyndns.info
David C. Partridge schrieb:
H I wasn't impressed.
On 3/8/11 9:57 AM, Kevin Watson wrote:
Hi Jim,
As part of my research into keeping time on rockets and spacecraft, I
joined
this list to see what I could learn from the masters. Of course I'm a
knuckle-head for not assuming that you'd be one of the resident masters
grin. Anyway, as my accuracy
On 3/8/11 11:41 AM, Chris Albertson wrote:
On Tue, Mar 8, 2011 at 9:57 AM, Kevin Watsontime-n...@enuuf.com wrote:
Hi Jim,
As part of my research into keeping time on rockets and spacecraft, I joined
this list to see what I could learn from the masters. Of course I'm a
knuckle-head for not
On 3/8/11 1:45 PM, Magnus Danielson wrote:
Kevin,
On 03/08/2011 06:57 PM, Kevin Watson wrote:
Hi Jim,
snip
Do you, or anyone else, have a recomendation for the GPSDO? Jackson Labs'
(http://jackson-labs.com/) DROR seems like it might work, but I wonder if
there might be better alternatives.
OK really getting off topic
S without GPS timing Celphones would not work. How is this a bad thing?
That means the people talking and texting while driving, might actually stay
in their lanes.
Sounding pretty good to me.
We did not shut down Loran for some crazy plot. We did it to save the
On 3/8/11 11:05 PM, Magnus Danielson wrote:
On 03/09/2011 06:08 AM, Kevin Watson wrote:
Hi All. Thanks for responding. There are quite a few GPS receivers that
will work outside of the usual commercial-grade GPS limitations, but I'm
not too sure I need such a receiver. As my application is to
For me, this looks like a advertisement campaign only. Not very
sophisticated or ingenious. Read that you don't need LC-filters at the
output because of the LDOs. *lol* If the designer ever heard of corner
frequency??
And the ISL9000A is the same.
- Henry
--
ehydra.dyndns.info
David C.
Electronic Products is not a real engineering publication. It is a forum
purely for new product releases. Always has been.
Articles there are almost always written by applications engineers for the
product being touted.
I got it free for decades, and threw the magazine away at once, unread.
Hi John and group -
For us germans, american magazines always look overloaded with
advertisments. The marketenders don't like to hear that the generations
under 40-50 are mostly advertisment blind just by natural adaption.
The times where I read paper electronics are long gone. The Internet
Lots of people use GPS for timing because it's cheaper or more
convenient in a budgetary sens than alternate approaches. Here at JPL,
it's easier, in general, for me to put a GPS timing receiver and GPSDO
in a lab than it is to try and run cables from the house sources.
The latter requires
Magnus,
Drop the receiver and antenna out of the equation and
just provide a timing signal on launch pad...
I need to keep computers time synchronized from launch through at least
arrival on orbit so that time-tagged network messages can be played back
with some degree of fidelity. For
Jim,
I guess I should also have mentioned that I want to synchronize events
across the rockets with those happening in our mission operations, and thus
need a common time source. Furthermore, this is currently just an
experiment, and is not safety or mission critical. We have other GPS units
On 03/09/2011 03:09 PM, jimlux wrote:
On 3/8/11 1:45 PM, Magnus Danielson wrote:
Kevin,
On 03/08/2011 06:57 PM, Kevin Watson wrote:
Hi Jim,
snip
Do you, or anyone else, have a recomendation for the GPSDO? Jackson
Labs'
(http://jackson-labs.com/) DROR seems like it might work, but I
wonder
On 03/09/2011 03:15 PM, jimlux wrote:
On 3/8/11 11:05 PM, Magnus Danielson wrote:
On 03/09/2011 06:08 AM, Kevin Watson wrote:
Hi All. Thanks for responding. There are quite a few GPS receivers that
will work outside of the usual commercial-grade GPS limitations, but I'm
not too sure I need
Kevin,
On 03/09/2011 06:39 PM, Kevin Watson wrote:
Magnus,
Drop the receiver and antenna out of the equation and
just provide a timing signal on launch pad...
I need to keep computers time synchronized from launch through at least
arrival on orbit so that time-tagged network messages can be
Hi Magnus,
As I said in an earlier message, this is an experiment that I want to run
and would rather not touch mission and safety-critical GNC components, like
our navigation GPS receivers. Mass is not an issue.
-Kevin
- Original Message -
From: Magnus Danielson
Every now and then I see e-mails like these. I would like to remind everyone
that Synergy Systems, the USA distributor for the M12 series receivers, offers
Ham Radio and Educational (time nuts) users a new M12M with the precision time
firmware and an on board battery for only $59.18 with the
On 03/09/2011 07:58 PM, Kevin Watson wrote:
Hi Magnus,
As I said in an earlier message, this is an experiment that I want to
run and would rather not touch mission and safety-critical GNC
components, like our navigation GPS receivers. Mass is not an issue.
In that case, take a Thunderbolt,
On 3/9/11 10:58 AM, Kevin Watson wrote:
Hi Magnus,
As I said in an earlier message, this is an experiment that I want to
run and would rather not touch mission and safety-critical GNC
components, like our navigation GPS receivers. Mass is not an issue.
-Kevin
So this makes it pretty simple..
This is an alternative:
http://shop-emea.u-blox.com/abashop?s=274p=productdetailsku=553
Nice, as you can program it for PPS at 10KHz or some other frequency.
- Henry
--
ehydra.dyndns.info
Rick Hambly (W2GPS) schrieb:
Every now and then I see e-mails like these. I would like to remind
It has Demodulated IRIG as its main IRIG output, but it does have
one Modulated IRIG. Others have told me I want the Modulated IRIG; I
honestly don't know what the differences are, and I haven't gotten out
a scope to see.
--Jim
On Tue, Mar 8, 2011 at 4:25 AM, Rob Kimberley
Hello,
El 09/03/2011 19:58, Kevin Watson escribió:
As I said in an earlier message, this is an experiment that I want to
run and would rather not touch mission and safety-critical GNC
components, like our navigation GPS receivers. Mass is not an issue.
So I understand that timing is not
Thanks for the info!
I was adjusting the levels with alsamixer, which I suspect is a
digital mixer. I hadn't thought of the potential issues there.
I was using the onboard sound, but I also have a higher quality
Soundblaster sound card. Do some of these vary in quality so much as
to be unable
My clock generates a couple variants of IRIG-B. I wasn't able to find
docs on what variant of IRIG-B that NTP expects. I know one variant
(which I tested, but am not using, nor do I expect to work) is high
precision, and is supposed to include the same accuracy as standard
IRIG-B + 1kPPS.
--Jim
IRIG is sometimes provided as a digital code at something useful for
directly driving logic (I've seen this intended to drive TTL), and as
the same digital code amplitude modulating an audio frequency carrier.
The modulated audio is the kind of IRIG that is usually decoded by
the sound card
Hi Jim,
From what you've described, I think you need to use the modulated IRIG output.
I sent a previous email to that effect.
The audio card IRIG drivers expect IRIG B data
used to modulate an audio carrier (AM).
--
Russell
At 11:42 AM -0800 2011/03/09, Jim Kusznir wrote:
My clock
If there are already other GPS units onboard,
also be careful of interference. On some of our
balloon work we have had COTS GPS receivers that
would jam each other if placed to closely together.
It'd be a shame if your $50 cheapie jammed the
space-rated unit and sank the whole mission.
On 3/9/11 11:40 AM, Jim Kusznir wrote:
Thanks for the info!
I was adjusting the levels with alsamixer, which I suspect is a
digital mixer. I hadn't thought of the potential issues there.
I was using the onboard sound, but I also have a higher quality
Soundblaster sound card. Do some of these
Magnus,
Drop the receiver and antenna out of the equation and
just provide a timing signal on launch pad...
I need to keep computers time synchronized from launch through at least
arrival on orbit so that time-tagged network messages can be played back
with some degree of fidelity. For
Hi Tom, Kevin,
the JLT DROR GPSDO mentioned by Kevin in the original email may be
overkill for this application, as it is designed to provide very low phase
noise
under extreme vibration conditions, and it is state-of-the-art technology
and priced accordingly. It is designed to interface
Thanks Rick had no idea
On Wed, Mar 9, 2011 at 2:04 PM, Rick Hambly (W2GPS) w2...@cnssys.comwrote:
Every now and then I see e-mails like these. I would like to remind
everyone that Synergy Systems, the USA distributor for the M12 series
receivers, offers Ham Radio and Educational (time nuts)
On Wed, Mar 9, 2011 at 22:09, jimlux jim...@earthlink.net wrote:
OTOH, if you're building a rocket that's big enough to need something like
this, you can likely get the needed export licenses, or at least, comply
with the export control laws.
Wait, he _is_ exporting the whole rocket, anyway,
On Wed, Mar 9, 2011 at 5:43 PM, Sanjeev Gupta gha...@gmail.com wrote:
Can you claim a rocket launch as an Export Credit? Yes, Officer, we
will report to the Customs Department if this equipment re-enters US
Territory. We will keep track of it, thank you. And believe me, I
will know
On 3/9/11 5:43 PM, Sanjeev Gupta wrote:
On Wed, Mar 9, 2011 at 22:09, jimluxjim...@earthlink.net wrote:
OTOH, if you're building a rocket that's big enough to need something like
this, you can likely get the needed export licenses, or at least, comply
with the export control laws.
Wait, he
On Wed, Mar 09, 2011 at 08:01:31AM +, Poul-Henning Kamp wrote:
Well, how can you argue with closing a system that was aiding terrorists ?
The reason LORAN-C got killed was that DoD/DHS couldn't jam it if a
terrorist with a suitcase-nuke was trying to find his way to Congress.
Is
A good thing every air force base doesn't have a homing beacon. Oh wait,
never mind.
On 3/9/2011 10:54 PM, David I. Emery wrote:
On Wed, Mar 09, 2011 at 08:01:31AM +, Poul-Henning Kamp wrote:
Well, how can you argue with closing a system that was aiding terrorists ?
In message 20110310065452.ge6...@pig.dieconsulting.com, David I. Emery writ
es:
The reason LORAN-C got killed was that DoD/DHS couldn't jam it if a
terrorist with a suitcase-nuke was trying to find his way to Congress.
Is this tongue in cheek, or do you have any actual basis
for stating
El 10/03/2011 02:43, Sanjeev Gupta escribió:
On Wed, Mar 9, 2011 at 22:09, jimluxjim...@earthlink.net wrote:
OTOH, if you're building a rocket that's big enough to need something like
this, you can likely get the needed export licenses, or at least, comply
with the export control laws.
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