oop) is good enough for 100s.
Even if the difference to the PPS is only a factor of 1.6.
That's a quite decent oscillator.
Attila Kinali
--
In science if you know what you are doing you should not be doing it.
In engineering if you do not know what you are doing you sho
g on them are well
networked
with those who would use the standards, having a public discussion never came up
and thus no public draft policy was formed. But the revision process is mostly
complete, both should be published at by the end of the year, probably earlier.
Attil
d TCXO + PPS + control
loop
could indeed be lower than the individual components. But without a closer
look at what happens to the phase, it is hard to tell whether this is a
genuine effect of the control loop, an artifact of the simulation or simply
a bug somewhere.
Attila K
of noise values before the
run of the actual simulation might or might not feasible.
Generating noise samples with arbitrary time correlation online in a
streaming fashion has plenty of advantages, not just memory usage.
Attila Kinali
--
In science if you know what you are
mal behaviours" are?
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
-- Kobayashi Makoto
___
time-n
random numbers. A better approach is to use the
Ziggurat algorithm [7] which uses only about 72-80bit
of entropy per generated sample.
And before you ask, yes sigma-theta/bruiteur uses xoroshift1024*
and the Ziggurat algorithm ;-)
Attila Kinali
[1] Fractional Brownian Motions, Fract
Hey there!
As some of you might be aware, next week is EFTF/IFCS in Paris.
Magnus and I will be there and we were wondering if any other
time-nuts would be present.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are thing
s about what you need to know about how to design a GPSDO.
Sounds easy, doesn't it? ;-)
Attila Kinali
--
Science is made up of so many things that appear obvious
after they are explained. -- Pardot Kynes
___
time-nuts m
ile (high-doping concentration with an abrupt transition).
Or in other words an additional half a dozen processing steps
which cost a lot of time and money... especially for a single
diode on a chip.
Attila Kinali
--
The driving force behind research is the quest
ou
get both AM and PM noise.
Today, narrow line-width lasers are all phase noise (or rather
frequency noise) controlled, additional to being amplitude controlled.
The three major techniques for this are saturated absorption spectroscopy,
dichroic atomic vapor lock and Pound-Drever-Hall lock.
Sub-
nut mailinglist on how
to do this or that. I would especially look for the discussions
with Tobias Pluess around 2019/2020. There were some good ideas
passed around in those. But there are plent of others as well.
Just look at the archives and search for GPSDO and you will find plenty.
So I'm a bit careful in suggesting
things until know better what your setup is.
Attila Kinali
[1] "A Physical Sine-to-Square Converter Noise Model"
http://people.mpi-inf.mpg.de/~adogan/pubs/IFCS2018_comparator_noise.pdf
[2] "A Fresh Look at the Design of Low Jitter Hard Limiters
t bunch together with
"normal" noise processes, as their treatment/mitigation has to be done
differently.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder
. Unfortunately, as it is
103 papers
it is quite a bit of work and I currently do not have the time for this. So, if
someone
on time-nuts would have the time and willingness to do this, I would very much
appreciate it.
Attila Kinali
--
In science if you know what
onosphere and through that the PVT solution of various stations.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
that you don't get temperature gradients and hot/cold air bubbles
that move around.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
here. It contains some discussion of spurs,
but I don't remember whether it had a in-depth discussion of the
reference spurs.
Sorry that I can't give a more to the point answer. I haven't looked
into the the spur behaviour of PLL yet and thus have only the most
basic knowlege about it.
ead at the very least IEEE 1139[1], NIST TN 1337[2] and NIST
SP 1065[3]
Attila Kinali
[1] IEEE Standard 1139 "Definition of physical quantities for fundamental
frequency and time metrology"
[2] "Characterization of Clocks and Oscillators" NIS
tics
in the frequency domain) is mathematically nonsense and leads to violations
in the assumptions in the analytical tools we use.
Attila Kinali
[1] "New frequency counting principle improves resolution", by Johanson, 2005
https://doi.org/10.
like to capture when the shock-wave comes around the earth a
second time, which will be probably burried in the daily fluctuations we have.
Attila Kinali
--
Science is made up of so many things that appear obvious
after they are explained. -- Pardot Kynes
On Fri, 14 Jan 2022 21:20:03 +0100
Attila Kinali wrote:
> Then I looked at the Datasheet [1] (ok appnote) and guess what,
> that's no mere oscillator. That's a bona-fide OCXO. Vacuum packaged,
> nonetheless! Sure, it doesn't have the best stability compared to
> other OCXO,
DIL-14 sized OCXO, it's actually
quite good. And it's only the size of a regular XO too!
And this also explains the need for ceramic: an FR4 PCB would$
have too much outgasing that would then lead to drift.
Lovely device!
(Still think it's probably quite expensive)
Atti
around it to get good approximations:
https://www.youtube.com/watch?v=55c9wkNmfn0
(The second half of the video are unrelated Q)
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wo
be so much louder than the
artifact, that it would mask the artifact.
Attila Kinali
--
In science if you know what you are doing you should not be doing it.
In engineering if you do not know what you are doing you should not be doing it.
-- Richard W. H
now from experiments [1,2] that the noise levels can
be pretty substantial (like close to 0dB SNR) before localization
performance degrades noticably.
But yes, the customer is king and if he pays, why not deliver what he wants.
Attila Kinali
[1] "Sound localization
On Mon, 10 Jan 2022 12:35:17 +0100
Attila Kinali wrote:
> That said, are yo sure you need such stringend phase noise requirements?
> It's audio. Nobody is going to hear whether the noise is -60dBc or -80dBc @
> 1Hz,
> much less -120dBc.
To give here a bit more background: ps
reach that level. One of them is
the famous Oscilloquartz 8607 and its successor the Rakon HSO13/HSO14. But be
prepared
to pay the price of a small car for each of them. And there is the NEL ULPN
OCXO 1714a,
but I don't know how much that one costs.
Attila
tarting from 1µF should be enough.
Attila Kinali
[1] The Design of Low Jitter Hard Limiters, by Collins, 1996
[2] A Fresh Look at the Design of Low Jitter Hard Limiters, by yours truly, 2019
http://people.mpi-inf.mpg.de/~adogan/pubs/IFCS2019_collins_isf.pdf
[3] A
On Fri, 7 Jan 2022 12:32:10 +0100
Attila Kinali wrote:
> stable (e.g. LTC6655 or use a Jung SuperRegulator that uses an LM329/LM399 as
> reference).
Oops.. wrong chip... I meant the LT3042 low noise LDO here, not the reference...
Sorry about that.
(Though the LTC6655 would work as LDO a
ve to the heater determines how much delay the control loop sees
(can be easily several minutes) and thus make it unstable.
Attila Kinali
--
In science if you know what you are doing you should not be doing it.
In engineering if you do not know what you are doing you sho
er a leap second is needed and if
it is, what
direction it should be.
The IERS website contains quite a few documents on the whole process but you
will
have to do some digging to find the ones that describe what you are looking for.
Attila Kinali
--
Science i
ng
the price of the Option 08 beyond what a car cost
didn't recover its cost.
Sure, such a high stability oscillator doesn't have a
mass market. And it's definitely not a comodity item.
But there seems to be decent market even if its very
expensive.
Attila Kinali
--
The d
u are saying I have misread the papers/datasheets?
This could be indeed the case...
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And tha
ves the available Q and thus increases
1/f^2 and 1/f^3 noise.
Attila Kinali
[1] "A New Type of Balanced-Bridge Controlled Oscillator",
by Richard Karlquist, 1999
http://www.hpl.hp.com/techreports/1999/HPL-1999-6.pdf
--
The driving force behind research is the ques
Ericson, etc)
and Japan (NTT, KDDI).
But we are digressing from the time-nutty things...
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And tha
(Modern
quartz watches are amazing!)
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
On Thu, 23 Dec 2021 18:57:10 +0100
Attila Kinali wrote:
> On Thu, 23 Dec 2021 12:14:48 -0500
> Bob kb8tq wrote:
>
> > It’s a pretty good bet that the Vref is 5V
>
> A quick google lead me to this forum post:
> https://www.eevblog.com/forum/projects/a-look-at-my-symmet
.5V
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
-- Kobayashi Makoto
___
time-nuts
erence voltage?
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
--
gnal
directly into the clock. This way you avoid transmitting.
Alternatively, replace the electronics with some 802.15.4 system
(e.g., 6LowPan) and distribute time in this network. There are
plenty of developer boards available for this kind of stuff,
just check adafruit and sparkfun.
rather than python
itself.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
-- Kobayashi Makoto
___
/ please.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
-- Kobaya
es:
https://doc.qt.io/qt-5/qtwidgets-widgets-digitalclock-example.html
https://doc.qt.io/qt-5/qtwidgets-widgets-analogclock-example.html
and build on them.
Alternatively, allmost any GUI library for any language contains
a clock example that you could modify.
Attila Kinali
--
Th
to glass
and its effect, so I cannot comment on that.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
-- Kobayashi Makoto
___
s graph are CSO's,
They do <1e-15 over a range from 1s to 10k[4].
Attila Kinali
[1] Rakon HSO14
https://www.rakon.com/news/ultra-stable-oscillators-hso14-and-hso13-for-ground-based-applications
[2] T4 Science iMaser 3000
https://www.t4science.ch/products/imaser30
urther,
as now part of the field is in free air/vacuum instead of
being confined into the crystal.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. An
, it's worth it.
Attila Kinali
PS: I could go into a long rant about Germans still insiting
to write their Diploma/Master theses, even their PhD theses
in German, when even the French have switched to English
a decade ago. But this is not the place.
--
The driving force beh
ufacturers (Murata, etc).
Those should be good enough for that need. Still I would not place
them close to the MRT, if possible.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
times in the past, nobody has the tooling to do so.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do research.
om
first principles calculation of even Ca+ is beyond what current
computers can do. So people are still using approximations to
calculate the energy levels for these. Sorry, I can't point you
at papers at the moment. I know I have them somewhere on my
harddrive, but I cannot figure out where I put t
I was seeking.
And quite a bit that I wasn't but is very intersting. I need
to spend some quality time with it :-)
Thanks a lot and have a nice week!
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand
t of the HP 5071s is corrected by
measuring them against their Cs fountain once a month (IIRC).
Though, I think METAS is more of an outlier when it comes
to NMIs than the norm. There are plenty of NMIs that only
have only some Cs beam standards. And then there are some
that don't even have a local r
rule of thumb to evaluate
whether what we are trying to do makes sense or not.
Thanks in advance!
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's
better than that, either at shorter or longer τ,
then we are clearly deep in atomic clock territory. Either
hydrogen maser. caesium beam standard or cold atomic clock.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we do
gt; Do you have the SC10 OCXO in your SR620?
Yes, I have an SC10 in my SR620.
Attila Kinali
--
In science if you know what you are doing you should not be doing it.
In engineering if you do not know what you are doing you should not be doing it.
-- Ric
not logging the frequency of the SR620, so I cannot
make any more precise statements. (I really need to build some rig where
I can measure lots of 10MHz sources in continuously...)
Attila Kinali
--
In science if you know what you are doing you should not be doing it.
In
On Tue, 02 Mar 2021 22:42:45 -0800
Hal Murray wrote:
> The basic idea is to mount a magnet on a stiff wire so that it sticks out to
> the side of the pendulum arm, then mount a coil so the magnet will swing
> through it. Now pulse the coil to get the desired results.
This is basically
f you search for "Neubig" and
"crystal measurement", you should be able to find some of
the nice documents that Bernd Neubig has written on the topic.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don
ost and
power, if you have GPS available. So, for me, Rb standards
only become intresting beyond 1d.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about
people don't have the Swiss, with their pedantic time keeping,
taking care of mains frequency.
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And that's why we do
you can expect a 1:10 to 1:20 matching. If not controlled,
this will lead to a phase shift in the order of 0.01-0.03°/°C
of differntial phase shift between the paths at 3GHz.
Attila Kinali
[1] "A Physical Sine-to-Square Converter Noise Model", IFCS 2018
http://pe
parts would all be CNC'ed by an online machine shop.
Magnus just send me out to chase an (unrelated) paper and I stumbled
over [1] which describes the Hg standard that Cutler & Co built.
Remembering this discussion I thought it might be interesting to
some.
Attila
not be obvious to a youngster like me, I would very
much appreciate if you would let me know.
Thanks in advance
Attila Kinali
--
The driving force behind research is the question: "Why?"
There are things we don't understand and things we always
wonder about. And tha
of the first LNA stage in an amplifier chain
to get information on the total gain of the chain and correct for it.
Which would make it basically a fancy chopper-amplifier that operates
on the gain instead of the offset voltage.
Attila Kinali
--
The driving force behind research
On Fri, 30 Oct 2020 17:58:24 -0400
Bob kb8tq wrote:
> Simple answer: conductivity. You don’t get much heat capacity either way.
Ah.. so it is more important to have less temperature gradients
than having high capacity?
Attila Kinali
--
The bad part of Zur
copper instead of steel?
Attila Kinali
PS: Fun fact: Water has a volumetric heat capacity of 4.18 J/(cm^3·K)
at 25°C. We should fill OCXOs with water! :-D
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you
art of those sessions.
So, you are saying between Matthys, Frerking, Rhea, Cerda and Parzen
there isn't much value in this book?
Cool, that helps. Thanks!
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK choc
to make it "low noise". It will, however,
not give you the knowledge that you need to make it time-nuts level
of low noise. That requires quite a bit more theory.
Attila Kinali
--
The bad part of Zurich is where the degenerates
uld I find it in any library I have access to. Does someone
know where that was published, or who might have a copy of it?
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocol
the calculation.
Attila Kinali
[1] "A Physical Sine-to-Square Converter Noise Model"
by yours truly, IFCS 2018
http://people.mpi-inf.mpg.de/~adogan/pubs/IFCS2018_comparator_noise.pdf
--
The bad part of Zurich is where the degenerates
th
s frequency counter business and the CNT-90
is the continuation of the PM668x line, also sold as PM6690
by Fluke)
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
__
rs and
filters are. He probably had just a project that was used in
an Rb standard, so it's understandable he didn't go into those
details either.
Overall the presentation was a nice overview of his works.
Attila Kinali
--
The bad part of Zurich is where the degenera
limiting them (this includes some emails
I exchanged with people from UniNE).
If anyone wants to use that design, I am pretty sure the
people at INRIM are happy help you with that.
Attila Kinali
[1] "Simple-design ultra-low phase noise microwave frequency
synthesi
d added) noise, which wouldn't be possible
otherwise.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
___
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implement a feedback system such that the output of the
switched supply is kept at 2V above the output of the LDOs,
you'd reduce power dissipation quite a bit and should be able
to get away with D2PAK LDOs and a small heatsink.
Attila Kinali
--
The bad part
])
You want to read Adler's paper[1] at the very least before you start.
A look at the work byHuntoon/Weiss[2] and Kurokawa[3,4] is probably also
beneficial.
Attila Kinali
[1] "A Study of Locking Phenomena in oscillators", by Robert Adler, 1946
(repri
On Fri, 24 Jul 2020 01:37:04 +0200
Attila Kinali wrote:
> Due to a diode mixer not being a good multiplier (it only
> multiplies the signs and adds up the amplitudes... and has
> offset voltages when the switching happens) you will
> get quite strong second order components
put ports with
square wave signals. This should minimize second order harmonics
generation within the mixer. But I have not gone through the math
for this and thus cannot say how effective it would be.
Attila Kinali
[1] "Tutorial on the double balanced mixer"
. Nevertheless I hope it can
be of use for some. Please let me know what you think, especially if you have
ideas
how I could improve the tutorial for the next time I'm giving it.
Attila Kinali
PS: As this years IFCS is fully virtual, the registration is still open
o
they
slowly walk from one object to another, drawing a map of things and try to see
whether
there is a pattern somewhere. Whenever there is something that is not explaint
to
everyones satisfaction, you'll find someone that looks at it from a different
direction,
from a different angle, to see wheth
s most of the perfomrance.
The rest was "quiet easy".
Attila Kinali
[1] "Simple-design ultra-low phase noise microwave frequency synthesizers for
high-performing Cs and Rb vapor-cell atomic clocks", by François, Calosso,
Abdel Hafiz,
Micalizio, Boudot
should be good for quite a few things.
Cost for the small run (5 boards) they did was IIRC 600CHF per board.
I don't remember whether that included the MicroZedBoard or not.
Attila Kinali
[1] https://www.ohwr.org/project/r19-tdc-del-a/wikis/home
--
The bad part of
xplained on a napkin in 5 minutes.
But getting it to this remarkable perfomrance? Not without a lot of
trial and error. And even then, I wouldn't be sure.
Jupp! I need one of those! And I need to learn how exactly they work!
For SCIENCE! :-D
Attila Kinali
--
Sci
Attila Kinali
--
Science is made up of so many things that appear obvious
after they are explained. -- Pardot Kynes
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hort term noise on the
signal is lower than the noise floor of the measurement system (in laser
systems is called the correlation length).
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK c
Moin,
I just stumpled upon [1] which is a nice review paper of optical
atomic clocks. It isn't an introductory paper, but one that focuses
on the general build-up and the problems that arise.
[1] "Optical atomic clocks", by Ludlow, Boyd and Ye, 2015
https://doi.org/10.1103/RevModPhys.87.637
ere feels adventurous and wants to try to get to contribute
to UTC, please have a look at [1] for the exact conditions.
Attila Kinali
[1] http://www.bipm.org/utils/common/pdf/CC/CCTF/CCTF-WGMRA-Guideline_6.pdf
--
The bad part of Zurich is where the de
ok=usno=57078=58919
And compare it to, e.g. PTB:
https://webtai.bipm.org/database/canvas.html?utclab=ok=ptb=57078=58919
Attila Kinali
[1] "Characterization of Clocks and Oscillators" NIST Technical Note 1337,
by Sullivan, Allan, Howe, Walls, 1990
http://tf.ni
ifference. When I got my institute to disregard the fire/lightning
protection rules and let me put an antenna on the roof instead of
just out of my window (looking straight south), I saw almost an
order of magnitude improvement in adev at short tau.
Attila Kinali
--
Scie
red as 3390 Hz, this is in excellent
agreement with theoretically estimated value of 3385 Hz.
---schnapp---
Attila Kinali
[1] "Compact High-Performance Continuous-Wave Double-Resonance Rubidium
Standard With 1.4 × 10−13 τ −1/2 Stability" by Bandi, Affolderbach,
Stef
r clock back to the manufacturer. Otherwise, it simply runs out of Rb.
Damn! I didn't know that. Sorry for the wrong information.
Now I wonder where the Rb goes to. It's a closed system after all.
I'll have to ask them at the next conference (whenever that will be)
A
ng
the energy levels of an atom.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
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long term stability of Rb vapor cells.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
___
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http:/
aper and a very good idea, which works
> becuase their frequency source "bottoms out" in the MVAR plot:
> Frequency drift would mean you too many degrees of freedom.
Which paper is this? I couldn't find anything with with what
you mentioned above.
Attila Kinali
e underlying system model, not in
the noise. But I have only scratched at the surface of this topic, so
there is a lot I have not seen yet.
If someone here knows more about fractional control, I would really
enjoy a chat about the topic.
Attila Kinali
--
In sci
ne control loops.
Attila Kinali
[1] "Kalman Filtering", by Dan Simon, 2001
http://aug-roma.wdfiles.com/local--files/progetti:arpinpero/Kalman_filtering.pdf
[2] "Feedback control of dynamic systems" by Franklin, Powell, Emami-Naeini
--
The bad par
ictive power.
You can map any PID loop back to a Kalman formalism.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
___
time-nuts mailing list -- time-nuts
e correct me if I'm wrong, but that sounds like a
simplified version of a Kalman filter, with the only
predicted variable being the frequency of the LO.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DA
quot; to become the major player in cities and with that, in the
largest GNSS market: cell phones.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
___
tim
sonable
time to match up.
Attila Kinali
--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.
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