Paul wrote:
OK have been experimenting with a simple vlf receiver for 24 Khz.
Using an HP 3335a as the LO. The Tracor 900 d-msk-r
circuit. * * * I was hoping to see a 100 Hz somewhat steady
signal in phase relationship to my local 100 Hz reference. Thats
absolutely not apparent. Sorry
On 13 Sep 2014 01:23, Alexander Pummer alex...@ieee.org wrote:
just open the box, look for the wires which going to the magnet which
drives the minute hand and measure the period time -- not the frequency, it
is to low
yes analog quarz clock slows down as the battery get old, you will be
On 13 Sep 2014 04:39, David McGaw n1...@dartmouth.edu wrote:
The battery probably was going weak and the oscillator coming out of full
control by the crystal. The tuning-fork crystal used in RTCs is not as
high-Q as a MHz crystal. I have noticed clocks using these can go quite
slow at low
On Sat, Sep 13, 2014 at 8:08 AM, Dr. David Kirkby (Kirkby Microwave Ltd)
drkir...@kirkbymicrowave.co.uk wrote:
So if it the mechanics skips a pulse, one really needs some method of
measuring the position of the hands and recording that.
Better modern quartz movements, have circuitry in the
Hi
In this era of “everything runs at GHz” it’s a bit tough to reach back to the
sort of process used for watch IC’s.
The idea is to optimize for low power / low leakage. They make enough of them
that an application specific process can be used. The divide side of the chip
may have an Fmax of
there is only one magnet, which drives the fastest moving arm -- the
pointer for the seconds -- the other arms are connected via gears, by
the way that case with the weak periodically recovering battery is an
observed one, I connected a paper chart recorder to the clock and
recorded the
Interesting topic! Of course I no longer wear a watch since such a habit
after advancing well into retirement seems pointless but I did want to point
out that perhaps you could include the Bulova Accutron in your studies.
Long ago I fell on ice and landed on my wrist with the result that my
Charles I literally just sat down to do some math. What you say is the same
thoughts I have. The information I have on NAA says that for 200bit msk its
a total of a 100 hz shift +/-50 Hz. That makes no sense I would think it
would be at least +/- 100 Hz. They had in the past run a 100 bit msk. I
On 9/13/14, 7:33 AM, paul swed wrote:
Charles I literally just sat down to do some math. What you say is the same
thoughts I have. The information I have on NAA says that for 200bit msk its
a total of a 100 hz shift +/-50 Hz. That makes no sense I would think it
would be at least +/- 100 Hz.
Hi,
I have a small quantity of good used FRK/M100 lamps I am getting rid of.
Offering here prior to eBay.
$45.00 each which includes shipping in USA.
Contact me off list.
Cheers,
Corby
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To
The underlying NAA reference is UTC(USNO). How close they track it
I don't know.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be
I have 2 Trimble Resolution T receivers and I have compared the 1 PPS signal
between the 2 units. They are spec'ed at 15 nS accuracy.I am seeing
about
80 nS of jitter between the two. This is with about 6 satellites in view.
I was thinking about ways to improve this. Since this is a
Hi
Have they both completed a survey and does the survey make sense?
Bob
On Sep 13, 2014, at 10:41 AM, Peter Reilley pe...@reilley.com wrote:
I have 2 Trimble Resolution T receivers and I have compared the 1 PPS signal
between the 2 units. They are spec'ed at 15 nS accuracy.I am seeing
Hi Andrew,
Yeah, it was a pretty dumb mistake, but I think I learned my lesson. At the
very least, my scripts now allow me to skip as many initial samples as I like
before the data is plotted.
And, the PWM version of the chip is in. It's orders of magnitude more stable
than the audio DAC in
Yes, both have completed their surveys. During the survey process
I was getting up to 150 uS of error between the PPS pulses.
Pete.
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp
Sent: Saturday, September 13, 2014 4:33 PM
To: Discussion
I have 2 Trimble Resolution T receivers and I have compared the 1 PPS signal
between the 2 units. They are spec'ed at 15 nS accuracy.I am seeing
about
80 nS of jitter between the two. This is with about 6 satellites in view.
That sounds like too much. Are you also comparing to a
On 11 Sep 2014 04:35, Bob Stewart b...@evoria.net wrote:
I've ordered the PWM version of the PIC, and hopefully, since it's the
motor control version (as opposed to the audio version) it will have much
better noise performance.
I don't know the PIC but I would have thought chips for audio would
OOPS! CORRECTION.
I don't know the PIC but I would have thought chips for audio would be
optimised for low noise far MOOR than one for driving motors.
Ears are more sensitive to a bit of noise than motors.
I assume I have misunderstood you.
Dave
___
Hi David,
It's an odd situation. From the datasheet:
Note: The DAC module is designed specifically for audio applications and is
not recommended for control type applications.
I had hoped that it wouldn't be a problem for driving an OCXO, but my mistake.
The datasheet also notes that the
AeroAntenna
AT27751995
https://plus.google.com/u/0/photos/111617808980322733757/albums/6058672650441867201
-pete
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On Sat, Sep 13, 2014 at 1:33 PM, Bob Camp kb...@n1k.org wrote:
Hi
Have they both completed a survey and does the survey make sense?
Are all of the cables the same length? That includes the cables from
antenna to receiver and the cable carrying the 1PPS from the receiver to
where you are
Hi
When you read back the survey location do they make sense? If the antennas are
X m apart on at an angle of Y, how close do the locations agree with this?
Often the survey process is not adequate to ensure a good fix with this or that
antenna.
Bob
On Sep 13, 2014, at 5:00 PM, Peter
Hi
Where are you getting the “15 ns accuracy” number from? When I look at the
Trimble spec’s they have a number of errors described (like sawtooth) that are
larger than 15 ns.
Bob
On Sep 13, 2014, at 10:41 AM, Peter Reilley pe...@reilley.com wrote:
I have 2 Trimble Resolution T receivers
Look for AERAT2775_42+CR at
http://www.ngs.noaa.gov/ANTCAL/Antennas.jsp?manu=AeroAntenna
http://www.ngs.noaa.gov/ANTCAL/LoadImage?name=AERAT2775_42%2BCR%2BNONE.gif
Even if the phase offsets are different from what is printed on your
chokering, they do look similar. Do you have the
Thats what I am trying to understand. How good is good. Is it a useful
replacement for wwvb. Certainly kicks butt in signal strength.
Regards
Paul
WB8TSL
On Sat, Sep 13, 2014 at 2:03 PM, Poul-Henning Kamp p...@phk.freebsd.dk
wrote:
The underlying NAA reference is UTC(USNO). How
I have just two of the rings that look like this. Sadly the spec sheets are
missing from the box.
-pete
On Sat, Sep 13, 2014 at 3:38 PM, Björn Gabrielsson b...@lysator.liu.se
wrote:
Look for AERAT2775_42+CR at
http://www.ngs.noaa.gov/ANTCAL/Antennas.jsp?manu=AeroAntenna
I see in the Trimble Resolution T data sheet that they
say that the PPS signal is within 15 nS to GPS or UTC (1 Sigma)
when using an over determined solution in stationary mode..
I take this to mean that the PPS signal should be within 15 nS
and that comparing 2 units that there should be no more
The cables are not exactly the same lengths. Differences in length
will result in a fixed offset. I am not concerned about such fixed
errors, only jitter.
I am comparing the rising edges which is what the spec defines as the
reference edge.
Pete.
-Original Message-
From:
I've acquired a few new in the box Leica/AeroAntennas. Some boxes have been
opened.
https://plus.google.com/u/0/photos/111617808980322733757/albums/6052074218781475313
The complete assemble is Leica P/N 10147
The 'puck' antenna is P/N 10160
I would like to have Time-Nuts get first dibs
Does
Hi
I’m sure they expect you to take out the sawtooth error before you do the
comparison. Are you doing that?
Bob
On Sep 13, 2014, at 6:41 PM, Peter Reilley pe...@reilley.com wrote:
I see in the Trimble Resolution T data sheet that they
say that the PPS signal is within 15 nS to GPS or UTC
Forgot .. I'm in Portland, Oregon 97217
-pete
On Sat, Sep 13, 2014 at 5:00 PM, Pete Lancashire p...@petelancashire.com
wrote:
I've acquired a few new in the box Leica/AeroAntennas. Some boxes have
been opened.
Hi Pete,
I'll take a couple of these of your hands if possible.
I'm in Australia, but using a shipping agent in California, so it'll
just be domestic freight.
Let me know.
david
dho...@gmail.com
I've acquired a few new in the box Leica/AeroAntennas. Some boxes have been
opened.
Sorry Everyone,
I thought I replied only to Pete.
david
Hi Pete,
I'll take a couple of these of your hands if possible.
I'm in Australia, but using a shipping agent in California, so it'll
just be domestic freight.
Let me know.
david
dho...@gmail.com
I've acquired a few new in the
Hi Pete, I'd like to tentatively speak for one. Thanks!
Andy ◉ Bardagjy.com ◉ +1-404-964-1641
On Sep 13, 2014, at 5:13 PM, Pete Lancashire p...@petelancashire.com wrote:
Forgot .. I'm in Portland, Oregon 97217
-pete
On Sat, Sep 13, 2014 at 5:00 PM, Pete Lancashire
I have been told this is the spec sheet, but I can't say for sure since it
does not say Leica
http://petelancashire.com/pictures/LeicaL1Choke-ring_AT575-90_G.pdf
-pete
On Sat, Sep 13, 2014 at 5:00 PM, Pete Lancashire p...@petelancashire.com
wrote:
I've acquired a few new in the box
David,
I going to limit to one only at this price. Want to make sure as many list
members get the chance to have one.
Hope you understand
-pete
On Sat, Sep 13, 2014 at 5:18 PM, davidh dho...@gmail.com wrote:
Hi Pete,
I'll take a couple of these of your hands if possible.
I'm in
Within 15 ns to GPS or UTC (1 Sigma) means that the 1 sigma spread is
30ns.
You have two units and assuming completely uncorrelated errors that would
mean expected 1 sigma spread between them, of 42ns.
Seeing frequent cases of 80ns delta when the 1 sigma spread is 42ns, should
not be surprising.
I'll speak for one of the antennas... Shipping will be to zip code 35750.
Let me know the cost and I'll pay immediately. How do you prefer to get
payment? Paypal is good for me, or personal check if you desire.
dave M
Pete Lancashire wrote:
I've acquired a few new in the box
Hi
If you add the +/- 20 ns of sawtooth on top of that you can quickly get some
pretty big numbers.
Bob
On Sep 13, 2014, at 8:39 PM, Tim Shoppa tsho...@gmail.com wrote:
Within 15 ns to GPS or UTC (1 Sigma) means that the 1 sigma spread is
30ns.
You have two units and assuming completely
There is a slim chance more will show up
If still interested I will put your name on a list
-pete PHEW .. that was quick
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The last one has been spoken for.
I'll start a list if anyone is still interested, there is a slim chance
others may show up.
-pete
On Sat, Sep 13, 2014 at 5:00 PM, Pete Lancashire p...@petelancashire.com
wrote:
I've acquired a few new in the box Leica/AeroAntennas. Some boxes have
been
Pete, Bob,
For data on a Resolution-T that I tested see http://leapsecond.com/pages/res-t/
What I found: the raw 1PPS has a standard deviation of about 13 ns; with
sawtooth correction that drops to about 6 ns. If that sounds too good to be
true, I can double check the raw data, or even re-run
Offline
Tom,
Have you run the same sort of test on a LEA-6T, or do you know off the top of
your head what the std deviation is? I had naively expected it to be spot on,
but I see jumps every now and then, and I don't know whether it's something on
my end, or if that's expected.
Bob
Well it doesn't make any sense but by using a LO of + or-150hz I do get a
stable signal that at least allows me to get a sense of the stability of
the carrier. I am not using the tracor d-msk-r to see this. In fact I need
to relook at it may have an issue it does not seem to be doubling.
A big
The cables are not exactly the same lengths. Differences in length
will result in a fixed offset. I am not concerned about such fixed
errors, only jitter.
I am comparing the rising edges which is what the spec defines as the
reference edge.
Pete.
Pete,
Correct, the survey position
On 9/13/14, 7:13 PM, paul swed wrote:
If NAA is transmitting 200 baud then I would expect the MSK carrier to be
+/- 100 Hz. Not +/-50 Hz.
I'd expect the total shift to be half the baud rate: 100 Hz..
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