On 3/13/13 7:06 AM, Bob Camp wrote:
Hi
A GPS that uses position hold gets it's coordinates from one of two possible
sources:
1) You measure the actual antenna location with a precision survey grade GPS
and enter them.
--or--
2) The GPS does a survey for some amount of time. It averages it's o
On 3/23/13 7:27 AM, J. Forster wrote:
I think the date for the DST time change were altered some years ago,
hence the Win SW messes up. I keep the 'puter clock on local time for
convenience, and switch because eBay does. I am only concerned with
roughly accurate local time.
For the last few y
On 3/24/13 8:22 PM, Chris Albertson wrote:
On Sun, Mar 24, 2013 at 7:34 PM, EB4APL wrote:
I wanted to build a GPSDO using the Brooks Shera design since I read the QST
article. I asked him in Jan 2009 about his source code, because I wanted to
change the PIC to a more modern one and add some fu
On 3/25/13 7:17 AM, David Kirkby wrote:
I'm possibly looking for a 40 MHz source and I know some of the
rubidiums are programmable. But can any of the affordable ones be
programmed to work at 40.0 MHz?
I was looking for a source to drive this 144 MHz -> 10 GHz transceiver.
http://www.chris-bart
On 3/25/13 8:27 AM, David Kirkby wrote:
On 25 March 2013 14:36, Jim Lux wrote:
On 3/25/13 7:17 AM, David Kirkby wrote:
The TCXO oscillator is off the board and a separate item, but costs
£40 and then one ideally wants to lock that to a more precise source.
The oscillator will lock to an
On 3/27/13 3:20 PM, Bob Camp wrote:
Eight ohms at 28 volts would be just a bit under 4 amps. It's also
right at 100 watts. I'd be very surprised it you need anywhere near
that much current. You probably want a pure sine wave to keep
everything happy. A lot of the simple inverters are "sort of" s
On 3/29/13 9:09 AM, David J Taylor wrote:
FYI: Yet another use for GPS timing signals is proposed:
http://bits.blogs.nytimes.com/2013/03/28/a-marshall-mcluhan-approach-to-weather-forecasting/
==
It's already been done! GPS occultation sensors have been fitted
On 3/29/13 2:36 PM, Chris Albertson wrote:
COSMIC and (coming soon) COSMIC-2 also do GPS occultation.
Yes, but COSMIC is not a constellation of 12 satellites and it is not as
cheap either. These guys want to put up 12 satellites at a total cost of
only $160M
COSMIC-2 is a constellation of 6
On 3/29/13 9:01 AM, Bob Camp wrote:
Hi
Too much tuning range is easy enough to fix. Use a pot to set it on frequency and then
hook it to the rest of the "stuff" with a fixed resistor. The gotcha would be
if the poor thing drifts so much that it *needs* the wide range to stay in lock.
My guess
On 3/30/13 5:31 AM, Bob Camp wrote:
Hi
If you go back into the papers from the early 1980's there is one where they
used a high gain antenna and no knowledge of the coding scheme to pull timing
off of GPS. I believe it was at White Sands, but that could be wrong.
One can just run it into a
On 3/30/13 2:58 PM, Lizeth Norman wrote:
What a bunch of hooey. Another so called expert wasted hours of my time
because he can't be bothered to either note that code is buggy or just
can't be bothered..
If you don't want to release it, then don't. If you do and it's a POS,
Expect emails.
Let
On 4/1/13 3:06 PM, Bill Hawkins wrote:
Looking for a long, thin horizontal clock display for use above or below
a flat screen TV.
Tried searching for "bar clock" and got a lot of useless hits.
If you're bulding it.. Arduino is your friend.. there's tons of LED
displays of all shapes and siz
On 4/3/13 11:32 PM, gary wrote:
Can anyone translate this to English. OK, it is English, but you know
what I mean. It is supposed to be some new time service.
http://rts.igs.org/access/
Not exactly time service.. this is one of the entry points to do high
performance GPS geodesy. Of course
On 4/4/13 12:51 AM, gary wrote:
Isn't this what WAAS does?
http://igs.bkg.bund.de/ntrip/about
Yes..
There's lots of ways to get real time (or near real time) correction
data. WAAS is but one. TASS (experimental) is another. There's various
and sundry local High Accuracy Reference Netwo
On 4/4/13 7:52 AM, Herbert Poetzl wrote:
On Thu, Apr 04, 2013 at 02:32:09PM +, Mark C. Stephens wrote:
I wanted to have a look at what the Z3805A puts out on Port 2.
I can see the LEDS flickering on the BOB so its saying something.
I connected up a terminal program set to 96008N1 and it s
On 4/6/13 6:08 AM, Lester Veenstra wrote:
Any TimeNutter worth his/her salt can do that..right!
$100 Presto 23 qt canning style pressure cooker, electric heating
elements, thermocouple probes, some fiberglass insulation to reduce
conductive losses.
Do it in your backyard and have a straw b
On 4/6/13 6:55 AM, Bob Camp wrote:
Hi
On Apr 6, 2013, at 9:39 AM, Jim Lux wrote:
On 4/6/13 6:08 AM, Lester Veenstra wrote:
Any TimeNutter worth his/her salt can do that..right!
$100 Presto 23 qt canning style pressure cooker, electric heating elements,
thermocouple probes, some
On 4/6/13 12:44 PM, Ivan.Cousins wrote:
Here is a related Arduino project.
http://www.pjrc.com/teensy/td_libs_TinyGPS.html
This is where I get my Arduino boards.
I like the 32 bit Arduino processor for some applications.
http://www.pjrc.com/store/teensy3.html
I'm a big fan of their teensy3..
On 4/8/13 9:59 AM, Alan Melia wrote:
Hi all an interesting problem you may have encountered, I want to use a
GPS frequency standard inside a building with no opening windows
(opening windows are known as air conditioning in the UK :-)) )
This is part of a two day amateur microwave conference so
On 4/8/13 2:12 PM, Tom Van Baak wrote:
Alan,
Google for words like GPS re-radiator or GPS repeater. There are also units on
eBay. If not to buy, at least to study examples.
The one I have is made by www.gpssource.com but it seems you could build one
yourself. It's easy to test by looking at y
Inexpensive USB spectrum analyzer.. http://www.signalhound.com/
I think it has the ability to capture raw samples, too. (the BB60
definitely does.) They have a 10MHz ref input.
The spectrum analyzer has a phase noise feature
Phase Noise Plot
: Displays the phase noise amplitude, in dBc/Hz, vs
On 4/15/13 1:48 PM, Dr. David Kirkby wrote:
On 04/15/13 04:39 AM, Jim Lux wrote:
Inexpensive USB spectrum analyzer.. http://www.signalhound.com/
It's not that inexpensive. I assembled a 22 GHz spectrum analyzer based
on the HP 7 modular measurement system for about the same money.
On 4/15/13 8:36 PM, Chris Albertson wrote:
On Mon, Apr 15, 2013 at 8:23 PM, Tom Van Baak wrote:
I'd be curious what level of improvement is possible. It will depend on the
receiver and the antenna. I believe the NIST project uses fancy antennas
but normal M12 receivers. So there's hope for the
On 4/15/13 9:27 PM, Tom Van Baak wrote:
NIST SIM GPS common view pinwheel
described in one of the NIST reports as an aperture coupled slot fed
array that is better than a patch, but not as large and heavy as a choke
ring.
W. Kunysz, 2000, “High Performance GPS Pinwheel Antenna,” in
Proceedi
On 4/15/13 10:22 PM, Jim Lux wrote:
On 4/15/13 9:27 PM, Tom Van Baak wrote:
NIST SIM GPS common view pinwheel
described in one of the NIST reports as an aperture coupled slot fed
array that is better than a patch, but not as large and heavy as a choke
ring.
W. Kunysz, 2000, “High
On 4/15/13 10:40 PM, bg wrote:
Chris,
Chokering is not needed. Measured quality antennas are listed at
http://www.ngs.noaa.gov/ANTCAL/
Or at
http://www.geopp.de/index.php?sprachauswahl=en&bereich=0&kategorie=34&artikel=62
/Björn
A lot of the antennas on that list are ch
On 4/16/13 11:04 AM, Attila Kinali wrote:
On Mon, 15 Apr 2013 23:00:49 -0700
Jim Lux wrote:
the effect of a strong multipath (which is what the choke ring
suppresses) would be a LOT bigger than that..
Uhmm.. to my understanding, this is not quite true.
The choke ring does not surpress
On 4/16/13 5:19 PM, Sarah White wrote:
I just have to ask though... cake pans? really? I can't imagine it would
even be possible to modify a cake pan with enough accuracy to get a
usable antenna.
Sure.. cake pans, like other stamped goods, are actually pretty high
precision, because they're
On 4/16/13 8:28 PM, Mark C. Stephens wrote:
Actually, before I plugged the GPS antenna into the second unit, I checked out
where it last called home:
LAT N 36:01:05.225
LON E 128:41:48.761
HGT+1214.14 m (MSL)
Mt Palgong, according to Google Earth
Lots of transmitter towers up there,
On 4/17/13 4:26 AM, Bob Camp wrote:
Hi
The description from their tech guys is "Very high gain front end. It's a saturating
amp rather than a comparator."
I thought the whole point of fast ECL logic was that it never saturated.
Of course these days, one might have very fast saturating logi
On 4/16/13 9:17 PM, Lachlan Gunn wrote:
A few reasons:
- I am interested to see what can be done with the statistics of an
ensemble of oscillators---in particular, whether the additional measurements
can be used to get a timescale that is more stable than just GPS and OCXO or Rb.
-
On 4/17/13 12:18 PM, Chris Albertson wrote:
Another way to ask this question is "what is the effect of a small
deviation form the ideal dimensions?"
If we assume deviations of about 1/20th of a wavelength are OK then we can
allow about 1cm of dimensional error. Almost anyone using simple hand
t
There's a very nice picture of a pinwheel from Novatel on the back cover
of the March issue of GPS world..
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On 4/18/13 12:01 AM, Chris Albertson wrote:
If I read the paper correctly you can skip the choke ring if you mount the
antenna on top of a 2 meter or longer mast. Iron pipe comes on 10 foot
lengths. The choke ring is for portable survey antenna that can't be
placed on tall rooftop masts. I th
On 4/18/13 4:01 AM, David J Taylor wrote:
An interesting novel use of GPS "stray" signals
"ESA’s retired GIOVE-A navigation mission has become the first civilian
satellite to perform GPS position fixes from high orbit. Its results
demonstrate that current satnav signals could guide missions
On 4/18/13 11:02 AM, Magnus Danielson wrote:
On 04/18/2013 04:01 PM, Jim Lux wrote:
On 4/18/13 4:01 AM, David J Taylor wrote:
An interesting novel use of GPS "stray" signals
"ESA’s retired GIOVE-A navigation mission has become the first civilian
satellite to perform GPS
On 4/18/13 12:15 PM, Peter Monta wrote:
I wonder if there's any advantage in combining far-away GPS with X-ray
pulsar navigation (XNAV), which is said to be good to a few kilometers,
though long integration times are needed. For example, the rough system
time from XNAV could enable very long (a
On 4/18/13 1:40 PM, b...@lysator.liu.se wrote:
All of the "high quality" GNSS receiver manufacturers have their own
version of correlator that try to mitigate multipath. See for example
this Ashtech-document (for a ca 10 year old L1 only receiver (DG14/16)).
ftp://ftp.ashtech.com/OEM,%20Sen
On 4/19/13 7:30 AM, Attila Kinali wrote:
On Wed, 17 Apr 2013 20:16:24 -0700
Jim Lux wrote:
There's a very nice picture of a pinwheel from Novatel on the back cover
of the March issue of GPS world..
Has anyone a digital (or scanned) copy of that picture?
It's kind of diff
On 4/19/13 11:47 AM, Peter Monta wrote:
Hi Hal,
Why are X-Ray pulsars better than radio pulsars for navigation?
My impression is that it's easier to manage all-sky coverage at x-ray with
a small spacecraft package (I think millisecond pulsars generally emit at
both microwave and x-ray).
On 4/21/13 5:18 AM, Attila Kinali wrote:
On Sat, 20 Apr 2013 12:52:03 -0700
"Tom Van Baak" wrote:
For the rest of you:
http://www.leapsecond.com/images/gps-pinwheel-1.jpg
http://www.leapsecond.com/images/gps-pinwheel-2.jpg
Thanks a lot...
So the design changed slightly from what Kunysz r
On 4/21/13 10:37 PM, Stewart Cobb wrote:
Date: Sat, 20 Apr 2013 12:52:03 -0700
From: "Tom Van Baak"
To: "Discussion of precise time and frequency measurement"
Subject: Re: [time-nuts] pin-wheel antenna
Message-ID:
Content-Type: text/plain; charset="iso-8859-1"
There's a very
On 4/22/13 12:26 PM, Eric Fort wrote:
Thanks, figured someone who reads this list may be connected there...
not like precision timekeeping is a huge community.
Eric
On Sun, Mar 17, 2013 at 2:53 PM, Magnus Danielson
wrote:
On 03/17/2013 10:47 PM, Eric Fort wrote:
Would anyone on this list kn
On 4/22/13 3:15 PM, Hal Murray wrote:
dginsb...@gmail.com said:
First, the frequency offset of the microcontroller. I use a built-in
counting timer in the uC which runs at 84MHz to measure the duration between
2 PPS. What I get is ~84008000 timer ticks between two pulses, which
corresponds to a
On 4/23/13 6:54 PM, li...@lazygranch.com wrote:
http://www.aorusa.com/receivers/ar2300.html
Just a FYI.
Interesting..
I see they use the OEM GPS from Garmin. I wonder what kind of DO
performance they get, and whether they actually discipline the
oscillator or just measure it. Since they'
On 4/26/13 6:01 AM, Bob Smither wrote:
As many on this list are amateur radio operators the following might be of
interest:
http://www.phonesat.org/
The project asks amateurs to monitor transmissions from cell phones that have
been placed in orbit.
Except that the transmissions are from
On 4/26/13 9:18 AM, Chuck Forsberg WA7KGX N2469R wrote:
On 04/26/2013 06:01 AM, Bob Smither wrote:
As many on this list are amateur radio operators the following might
be of interest:
to track the satellites in real time."
Will radiation fry the cell phones before thy burn up on re-entry?
Th
On 4/27/13 9:40 AM, Gregory Muir wrote:
On Fri, 26 Apr 2013 17:59:21 -0700, Jim Lux wrote:
Total dose will be very small (after all astronauts live in LEO)
So you'd worry about cosmic rays and single event effects.
They fly a lot of unmodified commercial equipment on ISS (a
On 4/30/13 4:18 PM, li...@lazygranch.com wrote:
A bit OT, but back in the day there was what amounted to an X-prize for a real
accurate chronometer for navigation.
Make that way back in the day.
http://en.m.wikipedia.org/wiki/John_Harrison
And he had a heck of a time collecting. I suspect co
On 5/2/13 5:18 AM, Poul-Henning Kamp wrote:
In message <5182325e.4020...@t-online.de>, Volker Esper writes:
Rummor has it that the single piece price in the US is $1475 for just the
CSAC. Weather that's with or without the demo board
And for that price a SRS PRS10 is a better buy, unless you
On 5/5/13 1:48 AM, Magnus Danielson wrote:
On 05/05/2013 10:05 AM, Attila Kinali wrote:
On Sat, 4 May 2013 12:36:20 -0700
"Tom Van Baak (lab)" wrote:
Rule of thumb: quartz is best short term, Rb or H-maser mid-term,
and Cs by far the best long-term.
Ah.. so it's a fundamental limitation. An
On 5/5/13 8:42 AM, Richard (Rick) Karlquist wrote:
At HP in the 1990's, Len Cutler's group built some experimental
mercury ion standards for USNO (IIRC). They were of the
trapped ion type. BTW, it is important to understand that
the architecture is the key factor, not the flavor of atom.
When p
On 5/5/13 10:05 AM, Magnus Danielson wrote:
On 05/05/2013 06:50 PM, Jim Lux wrote:
On 5/5/13 8:42 AM, Richard (Rick) Karlquist wrote:
At HP in the 1990's, Len Cutler's group built some experimental
mercury ion standards for USNO (IIRC). They were of the
trapped ion type. BTW, it is
On 5/5/13 10:01 AM, Magnus Danielson wrote:
Hi Jim,
On 05/05/2013 03:59 PM, Jim Lux wrote:
On 5/5/13 1:48 AM, Magnus Danielson wrote:
The above is a summary of things collected from a variety of sources,
but I think this coarse walk-through of issues gives some insight as to
what issues pops
On 5/5/13 11:45 AM, Magnus Danielson wrote:
Hi Jim,
On 05/05/2013 07:33 PM, Jim Lux wrote:
On 5/5/13 10:05 AM, Magnus Danielson wrote:
They have been targeting this goal for a very long time. Several
interesting papers is to be found at PTTI, NIST etc.
Yeah.. some years (6 or 7?) ago, John
On 5/5/13 2:49 PM, Magnus Danielson wrote:
I have all the Hg-199 and Hg-202 I need for a few clocks, but in it's
natural mixture. Don't feel like building a separation facility...
Use the quadrupole system you're using as a trap as a mass-spec to do
the separation.
__
On 5/10/13 6:52 PM, Ed Palmer wrote:
Part of me thinks it's cute, part of me wants to kill it. :-)
https://www.tindie.com/products/akafugu/vetinari-clock
Ed
but.. what is the actual distribution? Is it white phase or white
frequency?
___
time-nu
On 5/11/13 9:29 AM, Ed Palmer wrote:
On 5/11/2013 5:32 AM, Magnus Danielson wrote:
On 11/05/13 06:48, Jim Lux wrote:
On 5/10/13 6:52 PM, Ed Palmer wrote:
Part of me thinks it's cute, part of me wants to kill it. :-)
https://www.tindie.com/products/akafugu/vetinari-clock
Looking fo
On 5/12/13 12:38 PM, Al Wolfe wrote:
Years ago we were taught that it was poor engineering practice to use
pots to trim a DC value, especially if any appreciable current was to be
drawn from the wiper. (Probably true for any kind of signal on a pot) It
seems that current through the wiper would e
rummaged through archives and couldn't find anything..
I've got some GPS-18's with the RS232 and 1pps output. BUT, I'm
wondering if anyone has tried to get timing with the USB version (Linux
or Windows..), and if so, is getting 1 millisecond absolute accuracy
feasible.
The underlying USB th
r. The
new board is only about 10W. You can see a payback on only 6 months
and you make $100 in the next 6 months. The power savings can also
pay for replacing the GPS receivers with serial units.
On Mon, May 13, 2013 at 7:43 AM, Jim Lux wrote:
rummaged through archives and couldn't find
Interesting product.. too bad they don't have a small antenna that could
be integrated with it. (or maybe they do, and my browsing around didn't
find it).
I've got a bunch of applications coming up for something which needs
synchronization at 1us to 1ms level for distributed data collection. T
On 5/14/13 8:54 AM, Chris Albertson wrote:
The problem is the PPS needs to be referenced to the same clock the PC
is using as a basis for system time. Yes, you could send the
counter's value periodically but that has the same problem of sending
the PPS, that is an un knowable delay.
The good
On 5/14/13 9:02 AM, Chris Albertson wrote:
The adafruit GPS has a built in antenna. But you can add an external one.
it doesn't say that it has an antenna, and all the pictures show it
connected to an external antenna.
But why use this for timing? They don't even give a spec for timing
acc
On 5/14/13 9:27 AM, Richard Solomon wrote:
You can buy the Adapter and Antenna over on the "evil empire" for a lot
less money.
yeah.. but you have to find it.
What I was wondering if someone sells an antenna that you just "stick on"..
Say you want a functional equivalent of the GPS18, but perh
On 5/17/13 5:07 AM, Grant Hodgson wrote:
A client company has sourced a quantity of 'New in Box' iSBC series
memory modules manufactured by Intel in the 1980s for a MULTIBUS based
computer system. These are still in their original, sealed packaging and
have been stored (for 25 years) in controlle
On 5/20/13 2:43 AM, Attila Kinali wrote:
Oh.. and connect the whole thing to a port on the PC that does _not_
have an internal USB hub.
That's a bit of challenge, I suspect.. A casual look at the PCs I have
around here running windows all seem to have on-mobo hubs when you
check Device Manag
On 5/21/13 8:29 AM, Chris Albertson wrote:
The question here, I think was about the day-to-day shaking, not a once in
a lifetime event. Seriously if there was a 1+g acceleration who'd care if
their OCXO was still running under that pile of rubble that used to be a
house. It is the days-to-day
On 5/25/13 7:22 AM, Bob Camp wrote:
Hi
PIC's have been around for a *long* time. The PIC16's came early on and were
followed by the PIC18's. Both are a bit dated at this point. The PIC24's and
dsPIC33's are actually very similar parts. The PIC33's form a third family
pretty much on their own.
On 5/25/13 10:55 AM, Chris Albertson wrote:
3) the "Pi" is almost PC-like and very easy to use. Costs about $40
and requires a HDMI or DVI monitor..
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On 5/25/13 2:10 PM, Paul wrote:
*Jim Lux*
S*at May 25 16:53:50 EDT 2013*
* 3) the "Pi" is almost PC-like and very easy to use. Costs about $40***>and
requires a HDMI or DVI monitor..
A $9 USB to 3.3V serial adapter connects to
the serial console unless you prefer ssh or VNC
On 5/26/13 9:00 AM, Chris Albertson wrote:
But for many applications, the inevitable overhead
(power, heat, external components, OS, etc) simply
eliminates the gain of having a better/faster CPU.
Sometimes I end up using a 6 or 8 pin PIC with only
a few lines of code to to solve complex problems
On 5/28/13 9:29 AM, Bob Camp wrote:
Hi
The cost of a BVA oscillator is primarily a function of the cost of the
blank used and secondarily a function of the resonator processing. You see
numbers in the $200 to $400 range tossed around for the blank (vs < $10 for
a good SC blank). The packaged res
On 5/29/13 7:37 AM, Mark C. Stephens wrote:
My 3585 is like that too, Unlocked messages until it warms up.
Unless you leave it plugged in, it must keep the oven warm while on standby.
I wonder if this is the case for the 8566 too?
yes.. most of those instruments have a "standby" where the oven
On 6/1/13 8:49 AM, Attila Kinali wrote:
On Tue, 28 May 2013 20:23:06 -0700
Jim Lux wrote:
The USO's we got for GRAIL from APL have ADEV<1E-13 from 1 to 1000
seconds, and then heads up at 1 decade/decade. The lowest ADEV is about
5E-14 at around 50 seconds, but it's pretty f
On 6/1/13 10:35 AM, Bob Camp wrote:
Both suffer from people talking about levels (-120 dbc or 1x10^-11) without mentioning
the offset or tau. Since both are highly dependent on the offset or tau that's not a good
thing. My observation is that ADEV is much more likely to be mentioned without an
On 6/1/13 1:46 PM, Bob Camp wrote:
Hi
For ADEV, a lot of oscillators have a sort of "floor" where the
ADEV is relatively constant, say from tau in the range10-1000
seconds, and then it rises up (from thermal effects and such), so
the shorthand is that the number quoted is that "floor value"
Y
On 6/1/13 12:02 PM, Scott McGrath wrote:
True
However with LORAN and to a lesser extent WWVB traceability process
was well/known and documented and had been in place for decades and
was easy to implement correctly With GPS not so much especially
with S/A. Supposedly the new satellites don't
On 6/1/13 2:51 PM, Magnus Danielson wrote:
On 06/01/2013 11:27 PM, Bob Camp wrote:
Hi
On Jun 1, 2013, at 3:34 PM, Magnus
Danielson wrote:
On 06/01/2013 09:02 PM, Scott McGrath wrote:
True
However with LORAN and to a lesser extent WWVB traceability process
was well/known and documented and
On 6/1/13 4:46 PM, Bob Camp wrote:
That is, NIST certifies publicly that WWV is "on frequency" and "on time" with
a certain precision. Do I need to go to NIST and pay them to give ma piece of paper that says
this, or can I use their published data?
Remember - the original post (and thus the
On 6/1/13 4:50 PM, Hal Murray wrote:
jim...@earthlink.net said:
It's also the knowledge of the process yield at each step which means you
can stay in business. APL knows how many to start at the beginning to
insure they'll have 4 at the end, 2 years later.
I assume there is a distribution.
On 6/1/13 4:52 PM, Magnus Danielson wrote:
So, what was your engineering question, really?
responding to Bob's comment that people just say "ADEV <1E-15" without
specifying a tau.
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On 6/2/13 11:59 AM, Chris Albertson wrote:
Recent talk about NTP servers. It seems the limit to their accuracy is the
quality of the crystal that drives the CPU clock. Most of them make really
good thermometers. I'd like to try and replace the crystal on a Raspberry
Pi with a signal derived fr
On 6/2/13 12:52 PM, WB6BNQ wrote:
Hello Mark and crowd,
I own one of these and I can guarantee that it CANNOT be moved without changing
the crystal, tweaking a
micro-minature coil value, and changing the firmware. And NO !, the company
would NOT send out the firmware
needed. However, if you
And we received signals from it on ISS at 1400Z this morning (we've got
an experimental software defined receiver doing a 48 hour test right
now). Shiny, new satellite only a few weeks old: I guess it works. At
least we were able to lock. It's still being commissioned, so it's
presumably marke
On 6/9/13 8:29 PM, Bill Hawkins wrote:
Hi, Thanks in advance.
Since this is a list for precise things, could you make your questions
more precise?
What sort of test cases?
What sort of calculations? Do you mean conversions?
What do you mean by "catching" an error - where would you c
On 2/13/14 10:09 AM, Chris Albertson wrote:
-- Forwarded message --
From: Chris Albertson
Date: Thu, Feb 13, 2014 at 8:58 AM
Subject: Re: Atmega?
I posted this off list, but I'm reposting on the list with mnor edits. I
think there might be people looking to buy stuff. If so he
On 2/13/14 4:27 PM, Bob Camp wrote:
Hi
The number of bits and the performance of the ADC’s on the Arduino’s is pretty
underwhelming compared to the stuff on other similarly priced MCU’s. If you are
doing a design where the ADC matters, a PIC or just about anything from TI or
Freescale will do
On 2/16/14 11:55 AM, Jimmy D. Burrell wrote:
I've looked at several different manufacturer GPS datasheets now
regarding the 1 PPS output in an attempt to compare apples to apples.
Some of them rate their 1 PPS output as something on the order of
"PPS signals have an accuracy ranging 10ns" which s
On 2/19/14 10:24 AM, Brooke Clarke wrote:
Hi:
This means that the concrete piers where many Cesium clocks and GPS
reference stations are located are bobbing up and down as if they were
on a ocean, although only tens of inches.
My GPS friends comment when you start getting to sub-meter preci
On 2/20/14 4:40 PM, Brian Lloyd wrote:
On Thursday, February 20, 2014, J. Forster wrote:
The large amplitude swings happen on a very short time scale too.
Certainly <1 second at times.
8-bits is 48 dB. 16-bit parts at 60kHz should be cheap now. Why bother with
AGC? Just make sure the ADC do
On 2/21/14 5:37 PM, Scott McGrath wrote:
It may be a downconverter rather than a filter some GPS time systems notably
ones by true time used an active down converter to transform signal to baseband
for long cable runs. Voltage to converter was rather high as I recall
Sent from my iPhone
On
I ran across these units
http://www.conwin.com/time-frequency_references-gps_disciplined-gps_references.html
and I found some references from a few years ago in the time-nuts
archives, but I can't find any data on phase noise, etc. for the
disciplined output.
The data sheet/user manual/etc ju
On 2/22/14 5:17 AM, Jimmy Burrell wrote:
I need some help with a 'noob' question regarding some practical
examples in some of the NIST literature. When attempting to compare
two clocks, I'm a bit confused on the subject of exactly how to use
my counter to compare a delayed clock relative to anoth
on my
sample unit were significantly worse than what they show in their plots no
matter what I tried, and quite large phase/frequency jumps when
disconnecting/re-aquiring GPS.
Drawbacks of NCOs versus GPSDOs I guess.
Bye,
Said
Sent From iPhone
On Feb 22, 2014, at 5:33, Jim Lux wrote:
I ran
On 2/22/14 6:06 PM, saidj...@aol.com wrote:
Jim,
not sure if I had sent these before, or if you found them in the archives,
here are my ADEV, phase noise, and frequency stability measurements results
of the FTS-250.
All I did was remove the GPS antenna for about 10 seconds during the test
to
On 2/23/14 8:11 PM, Daniel Mendes wrote:
This is a different breed of time nuttery than usual in this list but i
think that at least some of you will enjoy it:
http://www.behance.net/gallery/FLUX-1440/2420150
Found it at hack a day
An enormous amount of work went into painting the patte
On 2/24/14 6:08 AM, Chuck Harris wrote:
Really impressive would be to have it create the
patterns that make the numeric display out of only
several feet of slowly moving rope connected as a
loop... but that would require some thinking, rather
than just a brute force approach.
It's art, after
On 2/24/14 8:17 AM, Poul-Henning Kamp wrote:
In message
, Pete Lancashire writes:
http://www.hp.com/hpinfo/abouthp/histnfacts/publications/measure/pdf/1968_09.pdf
pages 8 & 9
As far as I know, those satellites never made it to orbit ?
Wasn't that Gravity Probe B.. which finally launched i
On 2/25/14 1:40 PM, Tom Van Baak wrote:
So what's all this about a Thallium Beam Tube???
For info about the pro/con of Thallium beam frequency standards, see:
http://tf.boulder.nist.gov/general/pdf/9.pdf
http://tf.boulder.nist.gov/general/pdf/211.pdf
http://leapsecond.com/history/1965-Metrolog
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