70us.
There is reason why I said one needs temperature compensation for
this kind of stability requirement ;-)
Attila Kinali
[1] http://www.abracon.com/Resonators/ABS07.pdf
--
Reading can seriously damage your igno
#x27;m pretty sure others, like Maxim and Linear have them too.
Attila Kinali
[1] http://www.ti.com/lsds/ti/amplifiers-linear/fixed-gain-products.page
--
Reading can seriously damage your ignorance.
-- unknown
___
t
tty sure an opamp in an SC-70-5 with four 0402 resistors
would do what you need, but might be a tad bit difficult to solder if you
don't have the right equipment.
Attila Kinali
--
Reading can seriously damage your ignora
ned around 2006 and officially
published in 2008, L1C even later). I have found publications from
2011 that still talk about E1 being BOC(1,1). So if you read anything
on the Galileo E1 or GPS L1C signals, check whether they got the
right signal or not :-)
Attila Kinali
[1]
ndpass (unless you trust the SAW filter
at the front) and some feedback for the AGC.
Attila Kinali
--
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To
sts are either in an oven or using a fine hot air gun
(like the Leister Hot Jet S with a 5mm nozzle). I have not seen anyone
being able to reliably solder a QFN with a soldering iron.
DFN are borderline. They can be soldered by hand, but you need
a steady hand and a microscope.
d line tester/weaver's glass) to see whether the joint is
ok and doesn't have any shorts.
HTH
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use
y were operating there. Otherwise you will have
some funny effects.
Attila Kinali
PS: Please be aware that Dave Jones is often borderline wrong with
what he presents in his videos. So take them with a grain of salt
and check any "facts" independently before relyin
tle. If you have a
> reference I'd be curious to read about it.
Apparently the cross correlation function of an MBOC with its BOC is not
exactly symmetric. I haven't understood the details yet (still reading)
but this popped up a couple of times in different papers.
BTW: how is the work on the
aking)
and uses an FLL on the atomic transition.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Mathes
ver time (aging, temperature, humidity).
If anyone has some data on that, for different types of cables, I
would appreciate getting a copy :-)
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological soph
costs more then the whole DDS scheme).
So, what did I miss? Why do people use DAC-EFC control instead of
the DDS scheme?
Attila Kinali
[1] "A narrow band high-resolution synthesizer using a direct digital
synthesiser followed by repeated dividing and mi
On Tue, 8 Dec 2015 17:32:17 +0100
Attila Kinali wrote:
> The only
> problem would be to get a narrow band 10.0MHz filter (I couldn't find
> one within 5 minutes of googling). 5 stages should cost around 50-70USD)
Correction: I should have looked at "Resonators" in
re is some heavy "damping"
of the noise through the divider stages anyways.
> I don't think parts cost is a big driver.
Unless you are a hobbyist.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
_
s
problems and its "low" resolution, when there is better methods known.
Or, whether I missed some important point that is not obvious from reading
an otherwise good paper.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
___
there. Can someone give me a hint what to look for?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson
nsformers is
the tripple Gilbert-Cell design, but that might be higher in noise.
(Heck, i should just sit down and do some noise calculations)
Additionally, there is a need for relative steep filters for 667kHz
Attila Kinali
--
It is upon moral qualities that a
z oscillator to
supply both LEA-6 modules.
If you do this, you could even go as far as to use the sawtooth correction
message to stear the reference oscillator. That way you wouldn't need to
measure the PPS output and could to a "fully" digital control system instead.
Moin,
Thanks everyone for their input. Unfortunately the last few days were
a bit stressy and I couldn't go through all the mails in depth yet.
I will do that in the following days and come back with more questions :-)
Attila Kinali
--
It is upon moral qualities t
d december 2014)
http://blog.dan.drown.org/beaglebone-black-timer-capture-driver/
http://blog.dan.drown.org/tcxo-beaglebone-black/
HTH
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the
al generator which will allow it to
> power on and locate itself (or rather decode the sythetic signals from
> the generator into a location).
Interesting. If you get access to the paper, i would be interested in
it as well.
Attila Kinali
--
It is upon mo
roximately half the interrupt latency of the BBB including kernel/software
induced latency). But yours goes up to +/-12us, ie is 6-12 times higher.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophi
ng that increases interrupt latency jitter
by a factor of 2-3? Why does the "console" OS still exhibit a jitter that
is a factor 2 to 3 higher than what i'd expect as interrupt jitter?
Attila Kinali
PS: could you please quote mails properly? It makes them m
mean 74LVC1G86?
Generally speaking: Faster CMOS better than slower CMOS in terms of phase noise.
(Though, I have yet to see actual measurements of this)
Single gate chips better than multi gate chips.
(no interference through the power supply of the different sub-parts)
inductor results in a
reactance between 62R (100kHz) and 12k (20MHz) for the input range.
Can you shed a bit of light on why you did those modifications
and what the intended effect is?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founde
e used a single resistive
devider, buffered it with a large enough C and then split that bias voltage
off with a 3.3k resistor each. This would get rid off the bias mismatch.
(though not of the mismatch of the transistors)
Attila Kinali
--
It is upon moral qualities th
teresting... i have to look into the old datasheets.
> > Single gate chips better than multi gate chips.
> > (no interference through the power supply of the different sub-parts)
>
> Well, you should wire the other parts into passive mode.
That would be a waste of good PCB s
> about this topic, so we can believe the number.
Is this documented anywhere publicly? I would be very interested
to read this.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in t
admit that noise in electronic circuits is for me still
something very unintuitive. And I am more often wrong than right, when
it comes to predicting noise behaviour.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and
ail.
But there is one thing about the arangement of the SR FF in the 4046[1]
that bothers me:
Although S = R = 1 is valid, it does lead to the output oscillating
between 0 and 1.
Attila Kinali
[1] Ti CD74HC4046A Datasheet
http://www.ti.com/lit/ds/symlink/cd54hc40
ave done wrong or what the cause is?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheso
As side note: when using an FPGA anyways, it might be good to use
something like a lambda divider [1,2].
I'm not so sure whether their explanation why this improves the noise
floor is the right one, but it definitly helps and is quite easy to
implement.
Attila Kinali
raw data says.
Due to the problems I had with the SR620s and what the group at the TU Vienna
experienced (I am currently using their equipment), we started to ponder
whether we should build our own, multi-input TICs. Especially considering
that we are about to design some ASICs which we expect t
an the 0.1s,
so that it misses a measurement once in a while and has to wait until
the next trigger arrives?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world
hing that is done fast. I expect it to take
at least half a year with a couple of highly motivated people as a team.
A year would be probably more realistic. And after that, comes a whole
lot of verification and qualification. But that could probably be done
together with PTB or CERN.
lot! This is some very valuable data.
If you could note also the exact circuits you used, that would help
to compare the circuits.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in t
On Sun, 17 Jan 2016 15:02:43 -0500
Lizeth Norman wrote:
> Who wants a scanned copy of the manual?
I think the best would be to upload it to Didier's manual site:
http://www.ko4bb.com/getsimple/index.php?id=manuals
Attila Kinali
--
It is upon moral qualitie
y, some were close to 0ps, for which
we have no explanation good explanation.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that founda
tion good explanation.
>
> Any on-chip PLL's with "spread-spectrum" to fudge EMI tests ?
Nope, the cyclone4 PLLs do not support spread spectrum.
Also, the 0ps positions were stable (suggesting some FPGA
internal feature to be the cause), but they weren't evenly
spread
are ok. As this is a heated part of the whole
circuit, i'd go for an capacitor that is rated for 35V@100°C or higher.
Good candidates for capacitor manufacturers are Kemet and AVX
(higher quality than the cheaper manufacturers and still reasonably priced)
Att
ere. I will try to squeeze that in, if possible.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
--
im)
>
> R_S_SMA_SIG_GEN_100MHz-02.pdf
Could you explain what we are looking at here?
Attila Kinali
--
Reading can seriously damage your ignorance.
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.
Attila Kinali
[1] "Optical Autocorrelation using Non-Linearity in a Simple Photodiode",
by Syed Abdullah Aljunid, 2007
http://qolah.org/thesis/thesis-syed.pdf
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological soph
Do you have references to those reports?
The only one i've seen is from the Finnish Alto University Observatory:
https://blogs.aalto.fi/metsahovi/gps-kellonajan-outo-hyppays-huomattiin-metsahovissa/#.VqecHW-Vtpg
Attila Kinali
--
Reading can seriously dama
-pass capacitor such that you get
a low pass cut-off frequency in the, let's say, 100Hz range, then you
should see the effect clearly in your measurements.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
___
ability but anything not so "embrace" is fine
> to me
I am not sure I understand what you mean here. Do you want to compare
your GPSDO to their H-maser? Or do you want to compare some local
reference you have using the GPSDO as transfer standard?
Attila
low, low price so why build it yourself? I think
> that there are several reasons, including but not limited to the following.
We don't ask here "why". If it's fun for you to do, go ahead. We wont
question your reasons :-)
Attila Ki
Theory and Properties of Piezoelectric Resonators and Waves"
by E. A. Gerber and A. Ballato, in Precision Frequency Control, Vol. 1,
pp. 48-118, Academic Press, 1985.
Thanks in advance
Attila Kinali
--
It is upon moral qualities that a society is ultimately fo
Remoin,
On Tue, 2 Feb 2016 14:33:01 +0100
Attila Kinali wrote:
> I'm looking for a paper, but cannot find it in a local library or
> digital form. Before I start ordering old conference proceedings,
> I wanted to ask whether anyone here has the paper and would be
> so kind to s
ave the short term stability (aka low noise floor)
of the TimePod, but beyond a second, it should give you good results. And
should be more than good enough to measure the ADEV of the devices we usually
deal with.
Attila Kinali
--
It is upon moral qualities that a soc
ns
on parkinglots :-)
For more information please read the webpage:
http://efts.eu
Attila Kinali
--
Reading can seriously damage your ignorance.
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To unsubs
out. Maybe you'll have to adjust
the firmware for it, which you can find on github [4].
Attila Kinali
[1] http://www.ke5fx.com/gpscomp.htm
[2] https://hackaday.io/project/6872-gps-disciplined-tcxo
[3] https://www.tindie.com/products/nsayer/gps-disciplined-ocxo/
[4] htt
ow consider basic gear like DSOs, SAs, DMMs,
> PSUs, and sig-gens as disposable as cell phones.
Definitly not. Yes, these have become basic gear you just have in an
electronics lab. But they are handled with care and you don't just buy
another if you just haven't have one at hand. Prop
kW. The arms are Fabry-Pérot cavities, i.e. resonators.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson,
model would have been.
For further reading I recommend to have a look at [2] to get the basics
and google for "adaptive control" and "system identification".
Attila Kinali
[1] "Kalman Filtering", by Dan Simon, 2001
http://academic.csuohio.edu/si
On Thu, 17 Mar 2016 06:20:00 -0700
jimlux wrote:
> On 3/17/16 2:56 AM, Attila Kinali wrote:
>
> >
> > As I am pretty sure not the first one to attempt something like this,
> > I would like to ask whether someone has already some software framework
> > arou
someone has any hints on what to use.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Di
oscillator models
for this kind of short and long term simulation?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
until I get close to what we measure.
> The EFC measures you have done so far indicate that your steering
> essentially operates as if you do where doing something similar to
> charge-pump operation.
Hmm.. can you elaborate a bit on why you think so?
Attil
tly less than 1-2ns)
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond A
degrading the accuracy. Of course, noise on the EFC
signal will have an influence on the crystal noise, and this noise can
be of 1/f^a type itself as well.
Attila Kinali
[1] "Large Sample Simulation of Flicker Noise", by Barnes and Greenhall, 1987
ht
on't have
the dead band issue (or at least not to the extend to be annoying) :-)
> Something according to those lines might be where your systems behavior
> can be explained.
Well, we do not really have a deadband (save the TDC resolution and
my guess is that the inherent noise in the
On Mon, 21 Mar 2016 11:31:23 -0700
Alex Pummer wrote:
> On 3/21/2016 6:00 AM, Attila Kinali wrote:
> > Given that the crytsal has an accuracy of better than 100ppm, then
> > even a very weak coupling at 128Hz should be enough to keep it locked.
> > Upper bound on the jit
ion of the James Miller GPSDO with the
Jupiter module)
Attila Kinali
--
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them
Attila Kinali
--
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instruc
ile. After a
restart of the fountain it's back to normal.
Attila Kinali
--
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On Sun, 27 Mar 2016 10:50:13 -0400
paul swed wrote:
> I do not have it but I stumbled into it on the internet. There was one
> paper it was military, naval observatory or NIST and it did indeed show
> failure rates of cesiums of the reference that were owned and it must have
> been 30-50 of them.
time order. When two nodes get close to eachother the algorithm
switches between using nodes A & B and using nodes A & C. This can
indeed be seen as a deadband behaviour.
I'll look further into that behavior as soon as we have some simulation
system running and I see more than
might confuse more than clarify
in the question asked.
Attila Kinali
Attila Kinali
--
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hanks. We might use that as a reference.
I got a student who will implement a simulation framework (including the
noise generation) for me over spring/summer, with the goal of making
it public under GPL as license.
> http://www.leapsecond.com/pages/allan/Exploring_Allan_Deviation_v2.pdf
&g
e_measurement_references.zip
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The
t :)
How good has this reference to be? How much frequency deviation does it
tolerate? How much phase and frequency drift does it tolerate?
It might be, that a good OCXO is already stable enough for QRSS.
Or just an cheap OCXO locked to an FE-5680 with a low (<10Hz)
loop bandwidth.
teger divisor of 24MHz. Ie 8MHz works but not 10MHz.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Mathe
divide chain
for the PLL instead of a divide-divide chain, is irelevant considering
how dirty the GPS module provided reference frequency is.
Attila Kinali
[1] "The sampling theorem in Pi and Lambda dividers",
by Calosso, Rubiola, 2013,
http://rubiola.org/p
ter again, decimate, filter
until you're down at a couple of Hz of bandwidth. Then mix the signal
down to DC with an 60Hz generated from an NCO and detect the phase.
Send phase value to PC using USB or ethernet interface.
Attila kinali
--
Reading can seriously da
eeks for the traveling
GPS receiver.
For the BIPM GNSS calibration setup, there is a paper from Jiang and
Tisserand that spells out the seen uncertainties[1]. And there is a paper
from last year, that compares the GNSS calibrator to a fiber link
with a 400km baseline[2].
At
On Mon, 11 Apr 2016 19:58:33 +0200
Attila Kinali wrote:
> The baseline is not the problem in this case, but the delay within
> the GPS receivers and the cables. To keep their variation below 1ns
> is already quite a challenge. The usual method for this is to have
> the whole GPS re
. Even more so, as I know
that u-blox itself warned users of their modules to ensure an electrically
quite enviornment around their modules, for maximum performance.
So, i would warn people buying those that they might be fakes...
Attila Kinali
--
Reading can seriousl
that this will be integrated into the above network as well.
In east europe, there are also few fibre links, but these are considerably
shorter and have no interlinks yet (and no planned, as far as i am aware of).
Attila Kinali
--
It is upon moral qualities that a society
have any pictures?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neil S
on comes from? Because
the formula you refere to in the HP journal is just a different
way of writing the standard two sample ADEV which you can also
find on wikipedia.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and
esginers of these networks are
fully aware of the security and reliability implications that come
with GPS (or GNSS in general). Maybe i should dig a little bit around
and see what's current common practice in europe.
Attila Kinali
--
It is upon moral qualities that a
lot of other places as well.
Like NIST Tech Note 1337. What other formula did you see and why did
it confuse you?
I am trying to figure out what makes ADEV & Co hard to understand,
so we could come up with a better explanation.
Attila Kinali
--
It is upon moral qual
can use the GPMC subsystem for this. Have a look at the TRM
and Documentation/devicetree/bindings/bus/ti-gpmc.txt.
I'm sure there are also some examples of DT bindings out there.
If you have trouble getting it working, you can ask in #beagle@freenode.
Attila Kinali
--
e to spurs. In order to not introduce some
weird oscillations in the control loop due to spurs in the reference
signal, you should use some narrow 10MHz filter at the input (at most
half the sampling frequency wide). One way to achieve that is using a
ceramic resonator which are available at 10MHz.
specially
if only an 8bit variant is used) and clock everything from a 38.8MHz
crystal. Either using a PLL to lock the 38.8MHz oscillator to the 10MHz
OCXO, or using a dual ADC and sample both reference and OCXO at the same
time.
Attila Kinali
--
Reading can seriou
d do the loop there (adds maybe
10-20 lines or so). (dont worry about overhead here. as forking is much
cheaper on unix than on windows, forking to play a wav once in a while is
not going to hurt)
Attila Kinali
--
Reading can seriously damage your ignora
ether I want short term stability (OCXO) or medium term (Rubidium)
> for my reference.
Hehe.. it looks like you are going down the time-nuts road ;-)
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technologi
se, there is quite a bit of modeling going on.
I have not had the time to dive into this topic yet, but I have
seen papers on a wide variety of topics in that general area.
But as I said, most of the "good" stuff is written by mathematicians
and some more mathematically inclined bilog
DEV data for space clocks.
Attila Kinali
[1] "Estimating the Allan variance in the presence of long periods of
missing data and outliers", by Sesia and Tavella, 2008
http://stacks.iop.org/Met/45/S134
--
Reading can seriously damage your ig
odule, especially the communcation protocol (no, "NMEA standard"
does not mean anything).
Unless you already bought a SE880 already, i would recommend to
go with one of the u-blox modules (preferably the timing modules)
or get a LTE-Lite from Jackson Labs.
se use a HC53 as the reference for your logger if its
jitter is ok for you.
And for comparison, for a XO you usually talk about jitter in the
order of 100fs to 1ps (10kHz-20MHz)
Attila Kinali
--
Reading can seriously damage your ignorance.
se 100nF+1M (~100kHz) on a
single gate inverter (usually LVC, but not always) and have
not seen any oscillation yet.
BTW: Does someone know about actual measurements of the small
signal transfer characteristics of a single CMOS gate?
It would be nice to put the above rule of thumb onto a more
solid fou
ocumentation
for the module. You just need to read it.
BTW2: is this a hobby project or is this a work project?
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of
a wild guess. I haven't seen anything like this done.
If you want a more precise answer i would need to think about the design
of the system for some time.
I guess using some cable/fibre between the telescopes is out of question?
Attila Kinali
[1] http://www.navipedi
ata? Each measurement will need
at least 40bit resolution, at 10MHz that's 50MByte/s. Even if you
say that the average rate is only a fraction of that and you use
lots of buffers, that's still a high data rate for a measurement
instrument.
Attila Kinali
--
Reading can se
On Tue, 26 Apr 2016 23:39:40 +0200
Ilia Platone wrote:
> BTW, the u-Blox NEO-M8N doesn't fit RTK specs (patched it returns RAW
> data): it works on band L1 (20cm range), what I need is a GPS module
> capable on wiorking on L1+L2 to get 1cm range precision (if it's correct).
L1/L2 receivers are
on a different frequency. Then use some SDR system to extract
the relative phase/frequency of each station.
Attila Kinali
--
Reading can seriously damage your ignorance.
-- unknown
___
time-nuts mailing list -- tim
cy.
Also keep in mind, that with GPS it is well known where the errors
come from and how big they are. Also lots of techniques are implemented
to counter those. With a DIY-GPS system, one would need to implement
those and measure their performance again, which would be a whole lot of work.
where you live that helps you with the
project.
Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Mat
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