Re: [time-nuts] Trueposition Antenna Location

4 (second choice) from ebay. Alternatively, get one of Nick Sayer's GPSDO, modify it to use a good OCXO and crank up its loop time constant. Do not get one of the Trimble UCCM, they have quite horrible frequency jumps. Attila Kinali -- It is upon moral qualities that a society

Re: [time-nuts] WWV Doppler Shift

tors for the ADC inputs, and an MCX one for the reference clock source. Attila Kinali [1] https://www.rtl-sdr.com/rtl-sdr-direct-sampling-mode/ [2] https://www.itead.cc/airspy.html?acc=cfcd208495d565ef66e7dff9f98764da -- The bad part of Zurich is where

[time-nuts] Fw: [Ann] 2019 European Frequency and Time Seminar, Besancon, France, July 1-5

Moin, I just reived the following annoucement by Enrico Rubiola. TL;DR: EFTS is a one week seminar where experts in their respective field teach various aspects of time and frequency control, measurement and disemination. If you are new to the field and need a jumpstart, it's highly recommended.

Re: [time-nuts] Lady heather on a Raspberry pi

d in the xset manpage) Attila Kinali -- Science is made up of so many things that appear obvious after they are explained. -- Pardot Kynes ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo

Re: [time-nuts] Need recommendation for GPS antenna for Oncore GPS module

imble, Novatel, Leica, Attila Kinali -- The bad part of Zurich is where the degenerates throw DARK chocolate at you. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/

[time-nuts] Multi-oscillator synchronization (was: Question about the PLL of Trimble Thunderbold)

to piggy pack on existing protocol on the cables or even whether it has to be done wirelessly, what the distance is, etc pp Attila Kinali [1] "Fault-tolerant Clock Synchronization with High Precision", by Kinali, Huemer, Lenzen, 2016 http://people.mpi-inf.mpg.de/~a

[time-nuts] cable delay variation (was: Question about the PLL of Trimble Thunderbold)

short lengths before a regeneration step happens, there isn't much need for dispersion compensation anymore. Unless you go for submarine cables or optical fibers, both of which have elements with negative dispersion inserted. Attila Kinali -- The bad part of Zuric

Re: [time-nuts] FW: Question about the PLL of Trimble Thunderbold

ere is any distance between the two oscillators. Otherwise you can get up to several ps per °C temperature change and meter cable length for run of the mill cables. If you have PTFE cables, you also want to keep them well above 25°C or well below 15°C, for the same reason. Att

Re: [time-nuts] Question about noisetypes and ADEV

ality of random numbers generated, but they shouldn't be relevant for the application at hand). Attila Kinali [1] "Stochastic Differential Equations", by Bernt Øksendal, 2013 (6th ed) [2] "The Ziggurat Method for Generating Random Variables",

Re: [time-nuts] Question about noisetypes and ADEV

The people here who are more knowledgable than me about nummerical computation should be able to give you a better answer. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the w

Re: [time-nuts] Noise of digital frequency circuits (was: Programmable clock for BFO use....noise)

referencing the 10MHz oscillator to the calculated fixes. Attila Kinali -- Science is made up of so many things that appear obvious after they are explained. -- Pardot Kynes ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubsc

Re: [time-nuts] Noise of digital frequency circuits (was: Programmable clock for BFO use....noise)

"comparator" in my paper. Hence the first gain stage already aliases the noise from its whole bandwidth, which can be a lot of noise if the BW is large. Hmm.. I probably should have made it more clear that the model I defined applies only to single gain stages and not to whole components

Re: [time-nuts] Noise of digital frequency circuits

On Thu, 20 Sep 2018 23:45:27 +0200 Achim Gratz wrote: > Attila Kinali writes: > > People talk of aliasing and sampling, but do not describe where the > > sampling happens in the first place. After all, it's a > > time-continuous system and as such, there is no

Re: [time-nuts] Fwd: IFCS-EFTF 2019: Call for Papers

when you work in the trenches and try to properly understand what is going on. So, if you think you have something that nobody has writen about before, please do so. Attila Kinali -- Science is made up of so many things that appear

Re: [time-nuts] 10 MHz -> 16 MHz

de a few capacitors) required. As the CPU itself and all the peripherals are not used, one can do other shenanigans with them, like playing the imperial march on a floppy drive. Attila Kinali -- The bad part of Zurich is where the degenerates th

Re: [time-nuts] 10 MHz -> 16 MHz

he fine measurement. Same works equally well for 12MHz. Attila Kinali -- The bad part of Zurich is where the degenerates throw DARK chocolate at you. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscr

Re: [time-nuts] Noise of digital frequency circuits (was: Programmable clock for BFO use....noise)

On Sun, 16 Sep 2018 23:06:06 +0200 Attila Kinali wrote: > [2] "A Physical Sine-to-Square Converter Noise Model," > by Kinali, 2018 Oops.. I forgot to add the link to the pdf, sorry http://people.mpi-inf.mpg.de/~adogan/pubs/IFCS2018_comparator_noise.pdf

Re: [time-nuts] Programmable clock for BFO use....noise

m harmonic mixers*. Attila Kinali * That is, if you don't like Λ-dividers or DDS -- The bad part of Zurich is where the degenerates throw DARK chocolate at you. ___ time-nuts mailing list -- time-nuts@lists.febo.com

[time-nuts] Noise of digital frequency circuits (was: Programmable clock for BFO use....noise)

Moin, On Sat, 15 Sep 2018 08:38:55 -0700 "Richard (Rick) Karlquist" wrote: > On 9/15/2018 3:26 AM, Attila Kinali wrote: > > > possible logic family for the task. Otherwise the harmonics of the > > switching of the FF will down-mix high frequency white noise down >

Re: [time-nuts] Programmable clock for BFO use....noise

Hoi Bert, On Sat, 15 Sep 2018 11:09:18 + (UTC) ew via time-nuts wrote: > What about the application and the trigger circuit Sorry, I don't understand what you mean. Attila Kinali -- The bad part of Zurich is where the degenerates th

Re: [time-nuts] Programmable clock for BFO use....noise

109/58.56498 Attila Kinali -- The bad part of Zurich is where the degenerates throw DARK chocolate at you. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mail

Re: [time-nuts] Programmable clock for BFO use....noise

cycle. Otherwise flicker noise which has been up-mixed by a previous stage, will be down-mixed into the signal band, increasing the close-in phase-noise. Attila Kinali [1] "Modeling Phase Noise in Frequency Dividers," by Egan, 1990 [2] "The Sampling Theorem in

[time-nuts] GNSS beam forming (was: NIST)

lly available to the general public > right now, the best bet is a local atomic reference with a GPSDO used > to monitor and initially set it. There is a reason why Microsemi is building more 5071 these days than ever before (rumors have it that they are are 3-4 devices per week).

Re: [time-nuts] NIST

nd tropospheric effects limited the performance, which also could not be averaged over several satellites. Hence most people today focus on whole constelation systems and try to get the best out of that, even under multipath and jamming. Attila Kinali -- It is upon moral q

Re: [time-nuts] WWV and legal issues

moderate distances (like ~500km). Unfortunately I don't have any measurements at hand. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world i

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

On Tue, 21 Aug 2018 02:29:57 +0200 Attila Kinali wrote: > For control loops, I usually recommend Franklin's book[6], which > gives a good introduction, but does not cover any of the advanced > topics which you will need for a GPSDO. But even just the basics > will get you to a w

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

On Mon, 20 Aug 2018 11:46:15 +0200 Nicolas Braud-Santoni wrote: > On Mon, Aug 20, 2018 at 01:15:10AM +0200, Attila Kinali wrote: > > The online shop still works pretty well, as far as I am aware of. > > If you order more than 10-20 LEA/NEO modules, I recommend going > > thr

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

e generally designed directly for this frequency and don't use a PLL) Attila Kinali -- The bad part of Zurich is where the degenerates throw DARK chocolate at you. ___ time-nuts mailing list -- ti

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

. They were designed by people who know these things. > - I would need anyway to be able to validate that the PLL works correctly > and gives the expected accuracy, with a known-good GNSS receiver. If you build a GPSDO using a GPS module, you still have to vialidate it works correctly by c

Re: [time-nuts] High-end GPSDO's

ugh bits should do, or a divider scheme like Rick's synthesizer[1]. Attila Kinali [1] "A narrow band high-resolution synthesizer using a direct digital synthesizer pollowed by repeated dividing and mixing," by Rick Karlquist, 1995 http://www.karlquist.com

Re: [time-nuts] High-end GPSDO's

On Sat, 18 Aug 2018 20:53:19 +0200 Attila Kinali wrote: > Just to avoid confusion: I don't want to bash the FS740, not at all. > It's a very well designed device with lots of ingenious solutions for > small details (see also my quick review of it at [2]), but it's still &

Re: [time-nuts] High-end GPSDO's

On Thu, 16 Aug 2018 17:14:55 -0400 Bob kb8tq wrote: > It’s not at all clear what sort of GPS they have in these boxes. The FS740 schematics say it's some Trimble chip/module, probably one of the Trimble SMT modules, which one, I do not know. Attila Kinali --

Re: [time-nuts] High-end GPSDO's

s precision of the SR620 for something like GPS. Even 100ps is more than good enough. Attila Kinali [1] "Architecture, Design Aspectas and Performance of a New Cesium Beam Frequency STandard", http://leapsecond.com/corby/5071comb.pdf [2] http://lists.febo

Re: [time-nuts] Choosing a GPS IC for carrier phase measurements

ou only want GPS L1 C/A, then you can use the design of The Witch Navigator[1] with one of the VHDL/Verilog projects out there (e.g. cu-hw-gps [2]) If you want to go for L2C, L5 or Galileo, you have to do your own coding :-) Attila Kinali [1] http://www.witchnav.cz The

Re: [time-nuts] GPS receiver local oscillator

7;t ment seriously... Especially considering that Maxim has a lot of very specialized ICs that fill the needs left by the other, larger manufacturers. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological soph

Re: [time-nuts] GPS receiver local oscillator (was: 1PPS for the beginner)

cost of less than 10$. Adding a 2$ component will seriously hurt the ability of the CEO to buy a new Porsche with his next bonus. ;-) Attila Kinali -- The bad part of Zurich is where the degenerates throw DARK chocolate at you.

[time-nuts] GPS receiver local oscillator (was: 1PPS for the beginner)

rce at least for the baseband processing. But using a dithered frequency source means using a frequency source with a (very) bad phase noise. Which reduces the SNR quite considerably. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All

[time-nuts] GPS receiver local oscillator (was: 1PPS for the beginner)

;s already a DAC that has a price tag, multiple times that of the TCXO. Hence it's cheaper just to shift the frequency/phase digitally and not touch the TCXO. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technolo

Re: [time-nuts] Pressure related rubidium oscillator aging

ugh. 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, Neal Stephen

Re: [time-nuts] Pressure related rubidium oscillator aging

lass is not instantaneous. It if you change the outside pressure so much that you get into the "vacuum" range, you will cause a lot of strain on the glass, which in turn will lead to (inelastic) deformation (aka creep). Attila Kinali -- It is upon moral qualities t

[time-nuts] PPS pulse length (was: 1PPS for the beginner)

TvB wrote, it varies from a few µs to a few ms. 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 Diam

[time-nuts] GPS receiver local oscillator (was: 1PPS for the beginner)

, either as RF LO source or for the baseband processing. But this ring oscillator is always locked to some XO/TCXO to improve its stability. Attila Kinali [1] You can do longer integration times with normal XOs as well, but then at some point the noise and (in)stability o

Re: [time-nuts] WTS: Efratom PTB-100 Precision Timebase

up with a heat gun and let the rubidium condense again at the nook where it is supposed to be. Attila Kinali -- The bad part of Zurich is where the degenerates throw DARK chocolate at you. ___ time-

Re: [time-nuts] Replacement A9 boards for the HP 5065A

e pin compatible, beside the missing offset compensation. Unless you are using a chopper opamp for drift compensation, the ADA4077 might be worth considering. The higher GBW and slew rate would be benefitial in an integrator application like the A9 board, as it improves linearity.

Re: [time-nuts] Looking for PZT3904T1G transistors

nsitently marked. Attila Kinali [1] https://eu.mouser.com/ProductDetail/Central-Semiconductor/CZT3904-TR?qs=sGAEpiMZZMshyDBzk1%2fWiw99kSkYzPxmy7bnaX%2fesfk%3d -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the wor

Re: [time-nuts] 1 pps sync'ing

On Fri, 29 Jun 2018 16:37:41 +0200 Attila Kinali wrote: > How about just using an FPGA then? If you clock it at 200-400MHz, > then you can built a digital phase stepper with 2.5-5ns step size. > The FPGA can also handle the synchronization to an external pulse > quite easily

Re: [time-nuts] 1 pps sync'ing

tched up to 1-2cm, that should be enough. 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 Ma

Re: [time-nuts] HP 5065A A1 replacement with DDS

tor and integrator? Or does the Dick effect already limit you? 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. -- Mis

Re: [time-nuts] 1 pps Sync'ing

accuracy anyways. If only precision time comparison is required, IIRC the current limit is around 50-100fs. And even that requires a lot of work and characterization. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prospe

Re: [time-nuts] HP 5065A A1 replacement with DDS

delta-sigma modulators, which neither of the papers take into account (for obvious reasons). For that, I suggest having a look at [3]. Attila Kinali [1] "How to Predict the Frequency and Magnitude of the Primary Phase Truncation Spur in the Output Spectrum of a Dir

Re: [time-nuts] HP 5065A A1 replacement with DDS

48bit would be in the order of 3k-8kLE) and you can employ additional techniques to minimize spurs due to the non-linearity of the DAC. Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophisti

Re: [time-nuts] HP 5065A A1 replacement with DDS

On Sun, 24 Jun 2018 20:06:17 +0200 Attila Kinali wrote: > Oops... I just realized that the mixer part number is wrong. > it should be LTC5599 instead of LTC5598. Or not... please ignore me.. I seem to be confused. Attila Kinalie -- It is upon moral qualities

Re: [time-nuts] HP 5065A A1 replacement with DDS

On Sun, 24 Jun 2018 20:00:22 +0200 Attila Kinali wrote: > Attached is the page of my notebook with the schematic of the idea. Oops... I just realized that the mixer part number is wrong. it should be LTC5599 instead of LTC5598. Attila Kinali -- It is upon mo

Re: [time-nuts] Low phase noise affordable GPSDO

ome passive splitters will increase your noise levels. The 1/f^a noise levels are unaffected by this, though. I would recommend going for a seperate distribution amplifier in order to keep the noise at a minimum. If you are fine with DIY, go for the design by Anders Wallin.

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