On Tue, 2 Jul 2013 17:06:47 -0400
jmfra...@cox.net wrote:
Valid concerns all. What I am building is a squaring circuit for
recovering the carrier from a WAAS GPS satellite. Granted there
is still some Doppler and other issues, but the accuracy would not
be bad and it just looks like a fun
On 7/2/2013 5:07 PM, time-nuts-requ...@febo.com wrote:
On the other hand, i know a guy who does sub-cm positioning with unmodified
LEA6-T, by logging their satelite phase data and heavy post processing over
hours of data and comparing it to a neaby basline of two stations with
known
Hi
There are two batches of GPS / WAAS sats up there:
1) The ones with numbers above 100 that are geosync and that only do WAAS
2) The ones with numbers = 32 that do nav. These are not geosync.
I believe the only ones with corrected / high stab clocks on board are those in
the second group.
Hi
Since the LEA6-T will do conventional RINEX dumps, I suspect that all they are
doing is very long averaging on the data. I doubt the LEA6-T is the magic part
of the setup.
Bob
On Jul 3, 2013, at 8:26 AM, Dan Kemppainen d...@irtelemetrics.com wrote:
On 7/2/2013 5:07 PM,
On Wed, 03 Jul 2013 08:26:14 -0400
Dan Kemppainen d...@irtelemetrics.com wrote:
On 7/2/2013 5:07 PM, time-nuts-requ...@febo.com wrote:
On the other hand, i know a guy who does sub-cm positioning with unmodified
LEA6-T, by logging their satelite phase data and heavy post processing over
On Wed, 3 Jul 2013 09:58:51 -0400
Bob Camp li...@rtty.us wrote:
Since the LEA6-T will do conventional RINEX dumps, I suspect that all
they are doing is very long averaging on the data. I doubt the LEA6-T
is the magic part of the setup.
It's not conventional RINEX. The data is stored in a
For those running a net4501 NTP server with the original clock, there are
some 33.333MHz TCXO modules on ebay for sale, item #181008085393. I
haven't received mine yet so I can't guarantee they will work, but they're
3.3v parts, so I think they will. They are Chrystek CXOHV8-HF3-33.333MHz,
data
On 7/3/13 6:58 AM, Bob Camp wrote:
Hi
Since the LEA6-T will do conventional RINEX dumps, I suspect that all they are
doing is very long averaging on the data. I doubt the LEA6-T is the magic part
of the setup.
or sending the RINEX files to JPL for processing...If you don't need
real time
Dan,
I agree with Bob. Google for words like u-blox LEA RINEX and you'll see how
it's done. Google also for words like: teqc, RTKLIB, OPUS. I can send you the
links and papers I found, or you can find them yourself. I use teqc and OPUS on
my Ashtech's. Not sure if the LEA-6T I have is RINEX
At the risk of hijacking a thread, shooting of the subject and just generally
bad etiquette for news group posting, I am running all my S1 NTP servers on HP
thin clients!
They only draw ~14 watts of power.
I have managed to fit a 3.5 inch laptop drive in the T150's so they run a
(minimal text
Hi,
I decided to buy a Nanos G20. Not too expensive, real serial port,
debian linux pre-installed.
I don't want to sound harsh as the people from Nanos probably did their
best to produce a good product, but for timekeeping it is totally crap
and also useless.
Well, unless I did something wrong.
I
List,
I'd like to buy or trade for a working HP 117A. I don;t need the HP antenna.
Please contact off line if interested.
Regards,
Perrier
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There are many ways to solve the SD card problem. One is to write the file
to a networked disk drive, or set up a disk image in RAM, but then you
loose the data if the power fails or you can use a small notebook disk in
place of the SD card.
You could write to the SD card in batches, say one
On Wed, 3 Jul 2013 08:29:02 -0400
Bob Camp li...@rtty.us wrote:
There are two batches of GPS / WAAS sats up there:
1) The ones with numbers above 100 that are geosync and that only do WAAS
2) The ones with numbers = 32 that do nav. These are not geosync.
I believe the only ones with
Moving past the loss of 60kHz continuous phase reference.
Do any of the commercially available consumer clocks/watches use WWVB's new
phase encoded time stamps instead of the backwards-compatible pulse-width
keying?
Any homebrew projects of note?
Potentially the BPSK encoding ought to offer
Hi
The pipe in this case is up on one frequency and down on another. The
conversion oscillator on satellite that's the weak link, no matter how good the
signal from the ground happens to be.
Bob
On Jul 3, 2013, at 1:48 PM, Attila Kinali att...@kinali.ch wrote:
On Wed, 3 Jul 2013 08:29:02
folk...@vanheusden.com said:
remote refid st t when poll reach delay offset jitter
==
x127.127.28.0.NMEA. 0 l3 16 3770.000 -994.05 7.857
x127.127.28.1.PPS.
A 'bent pipe' or retroreflector doubles any Dopplar from range rate.
-John
On Wed, 3 Jul 2013 08:29:02 -0400
Bob Camp li...@rtty.us wrote:
There are two batches of GPS / WAAS sats up there:
1) The ones with numbers above 100 that are geosync and that only do
WAAS
2)
Here's a review of several small low power linux systems:
http://www.cooking-hacks.com/index.php/blog/new-linux-embedded-devices-comparison-arduino-beagleboard-rascal-raspberry-pi-cubieboard-and-pcduino
Folkert van Heusden
--
MultiTail is a versatile tool for watching logfiles and output of
Hi,
I decided to buy a Nanos G20. Not too expensive, real serial port,
debian linux pre-installed.
I don't want to sound harsh as the people from Nanos probably did their
best to produce a good product, but for timekeeping it is totally crap
and also useless.
Well, unless I did something wrong.
Hi
If there are any BPSK products out there, it's a *very* well kept secret.
Bob
On Jul 3, 2013, at 2:00 PM, Tim Shoppa tsho...@gmail.com wrote:
Moving past the loss of 60kHz continuous phase reference.
Do any of the commercially available consumer clocks/watches use WWVB's new
phase
Attila,
On Wed, 3 Jul 2013 08:29:02 -0400
Bob Camp li...@rtty.us wrote:
There are two batches of GPS / WAAS sats up there:
1) The ones with numbers above 100 that are geosync and that only do
WAAS
2) The ones with numbers = 32 that do nav. These are not geosync.
I believe the only ones
Apparently this modulation scheme is less prone to jammers.
There is is British station which jams east coast WWVB.
Brian/K3KO
On 7/3/2013 18:00, Tim Shoppa wrote:
Potentially the BPSK encoding ought to offer much better decoding here on
the East Coast of US. Many of the commercially
http://www.navipedia.net/index.php/WAAS_Signal_Structure
Doppler Shift: The Doppler shift, as perceived by a stationary user, on the
signal broadcast by WAAS GEOs is less than 40 meters per second (≈210 Hz at L1)
in the worst case (at the end of life of the GEOs). The Doppler shift is due to
folk...@vanheusden.com said:
remote refid st t when poll reach delay offset jitter
==
x127.127.28.0.NMEA. 0 l3 16 3770.000 -994.05 7.857
x127.127.28.1.PPS.
Thanks for your graphs, but what are the Y-axis units!
http://keetweej.vanheusden.com/~folkert/nanosg20.png is in ms and not
the delay, the offset instead.
Inn your billboard above, the PPS looks to be on the wrong edge -
perhaps the pulse is 250 ms wide and you are syncing to the trailing
Sure about the bent pipe? If so it seems that much power is required
at the transmitting ground station...
On Wed, Jul 3, 2013 at 7:48 PM, Attila Kinali att...@kinali.ch wrote:
On Wed, 3 Jul 2013 08:29:02 -0400
Bob Camp li...@rtty.us wrote:
There are two batches of GPS / WAAS sats up there:
I assume you mean MSF...
Sent from Samsung Mobile
Original message
From: Brian Alsop als...@nc.rr.com
Date:
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Subject: Re: [time-nuts] BPSK decoder for WWVB
Apparently this modulation scheme is
Hi Bob,
On 07/02/2013 02:46 AM, Bob Camp wrote:
Hi
There's a gotcha with trying to anneal quartz. If you take it above the Curie
temperature, it'll twin when it comes back down. You will have random right and left
handed domains in the bar. Net result is that you can't get it hot enough to
http://www.wired.com/wiredscience/2013/07/wwvb-time-radio/
Tom Holmes, N8ZM
Tipp City, OH
EM79
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On 3 Jul, 2013, at 10:48 , Attila Kinali att...@kinali.ch wrote:
On Wed, 3 Jul 2013 08:29:02 -0400
Bob Camp li...@rtty.us wrote:
There are two batches of GPS / WAAS sats up there:
1) The ones with numbers above 100 that are geosync and that only do WAAS
2) The ones with numbers = 32
The computer itself and the NTP installation are OK because we can see it
syncing to other NTP servers. Likely you have a problem in the way the GPS
using is connected.
Some common errors is an inverted PPS, just flip it ad see if you gets
better, it is really hard to see a 1Hz signal on a scope.
Hi
The power at transmit is partially a function of making it tough for backyard
what ever nuts to broadcast through the sats. Since there's no demodulation /
decoding / encoding / remodulation, power is the only practical lockout
mechanism.
It's secondarily a function of the massive amount
On 3 Jul, 2013, at 11:47 , Bob Camp li...@rtty.us wrote:
The pipe in this case is up on one frequency and down on another. The
conversion oscillator on satellite that's the weak link, no matter how good
the signal from the ground happens to be.
That's certainly true but it doesn't seem
On Wed, Jul 3, 2013 at 4:14 PM, folkert folk...@vanheusden.com wrote:
Oh for convenience. I need to patch ntpd to use linux pps (afaik) and on
other systems I successfully run gpsd with ntpd (read: low jitter).
Using gpsd with ntpd reduces the jitter versus just using ntpd by itself?
I have heard MSF on 60kHz in our early evening on some winter nights but
never would describe it as jamming :-)
I have also heard YVTO on 5MHz underneath both WWV and WWVH, strangely
off-kilter by half a second or so.
Many evenings the Russian time stations are audible, offset by 4kHz from 5
and
Yes, according to:
www.jks.com/wwvb.pdf
Brian
On 7/3/2013 20:48, Rob Kimberley wrote:
I assume you mean MSF...
Sent from Samsung Mobile
Original message
From: Brian Alsop als...@nc.rr.com
Date:
To: Discussion of precise time and frequency measurement time-nuts@febo.com
It is a garmin 18x lvc.
That's pretty vanilla. It really should work. I won't be surprised if the
NMEA is off by hundreds of ms and/or has 100 ms of wander, but the PPS should
work.
Would you please try ntpd's NMEA driver, preferably from the latest ntp-dev
On Wed, Jul 03, 2013 at 05:03:40PM -0400, Tim Shoppa wrote:
I have heard MSF on 60kHz in our early evening on some winter nights but
never would describe it as jamming :-)
I have an MSF receiver, if only I could get rid of the
semi-local (1000 km) interference from WWVB. :)
I have
On 3 Jul, 2013, at 14:03 , Tim Shoppa tsho...@gmail.com wrote:
I have also heard YVTO on 5MHz underneath both WWV and WWVH, strangely
off-kilter by half a second or so.
When BPM does that, like maybe at the beginning of this
http://www.youtube.com/watch?v=WRaRB-x84xg
I think it is
You could also try questi...@lists.ntp.org.
The developers etc hang out on that list.
There are a lot of helpful experts on NTP there.
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of Hal Murray
Sent: Thursday, 4 July 2013 8:34 AM
To:
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