Re: [time-nuts] PPP GPSDO v2 - ADEV ~3e-13, e-14 at ~2000 seconds

Sorry, typo in the link to the data: http://www.efos3.com/downloads/GPSDO_brux_28.05.18.zip On Mon, May 28, 2018 at 10:46 AM Ole Petter Ronningen <opronnin...@gmail.com> wrote: > Hi, All > > Another somewhat long winded post, my apologies. First off, thank you Bob > for enco

[time-nuts] PPP GPSDO v2 - ADEV ~3e-13, e-14 at ~2000 seconds

Hi, All Another somewhat long winded post, my apologies. First off, thank you Bob for encouragement and good advice! A couple of weeks ago I posted some results from a GPSDO based on a geodetic GPS dual frequency receiver and real time PPP, hitting e-14 at around 6-7.000 seconds with an adev

Re: [time-nuts] Sub 5e-13 ADEV GPSDO

Hi, Bert Yes, the ionosphere is most definately taken out of the equation using this method, as is a few other effects such as solid earth tides. I am working on a writeup here http://www.efos3.com/GPSDO/GPSDO.html Still work in progress, but it has come along some way - you're welcome to a

[time-nuts] Sub 5e-13 ADEV GPSDO

Hi Perhaps this is of interest to some. I finally got around to doing an experiment I've been mulling over for some time. In short, I use a Novatel OEMV-3 GPS receiver, clocked by an Oscilloquartz 8600 BVA, process the observations with RTKLib and real time corrections from igs - and use the

Re: [time-nuts] nuts about position (cheap receiver)

In my experience, there is little difference between the Final and Rapid, which will be out just about now (for yesterdays observations) Ole On Thu, May 3, 2018 at 6:26 PM Mark Sims wrote: > To give an idea about the possible improvement in antenna location > available by

Re: [time-nuts] nuts about position

Hi I just ran a quick test - a Ublox 6T was configured to output the RXM-RAW messages every second and logging for some 14 hours using U-Center. The .ubx-file was converted to RINEX using teqc.exe, and uplaoded to NrCAN PPP. NrCAN PPP will process single frequency observations and correct using

Re: [time-nuts] ADEV slopes and measurement mode

Thanks! I think it will require more than one reading.. :) Ole On Thu, Apr 19, 2018 at 12:08 AM, Magnus Danielson < mag...@rubidium.dyndns.org> wrote: > Hi Ole Petter, > > On 04/16/2018 12:12 PM, Ole Petter Ronningen wrote: > > Hi, All > > > > This wi

Re: [time-nuts] 53230A weirdness

016 in York? > > I remember they borrowed your 53230A for that work. > > Cheers, > Magnus > > > On 11/23/2017 09:05 PM, Ole Petter Ronningen wrote: > >> Hi, all >> >> I've done some experiments on my 53230A, and I've come across an issue I >> thin

Re: [time-nuts] 53230A weirdness

borrowed your 53230A for that work. > > Cheers, > Magnus > > > On 11/23/2017 09:05 PM, Ole Petter Ronningen wrote: > >> Hi, all >> >> I've done some experiments on my 53230A, and I've come across an issue I >> think could be worth knowing about. >> >&g

[time-nuts] 53230A weirdness

Hi, all I've done some experiments on my 53230A, and I've come across an issue I think could be worth knowing about. I have not tested this on other 53230A's - if anyone has a 53230A and some spare time, I'd be grateful if someone could try to replicate. In a nutshell, the first frequency

Re: [time-nuts] H-Maser drift (was: Why discipline Rubidium oscillator?)

> > > > 4.5 liters in EFOS type masers - so not *that* small. I believe other > > masers are the same order of magnitude. > > Hehe.. Yes. It's "small" compared to the cavity. Depending on the > exact cavity construction, the storage space can be as small as > a tenth of the total cavity volume.

Re: [time-nuts] H-Maser drift (was: Why discipline Rubidium oscillator?)

On Tue, Nov 21, 2017 at 2:50 PM, Attila Kinali wrote: > [...] The advantage of the platinum valve > system is that it "generates" single atom Hydrogen, as required > by the maser. Picking nits here.. It was my understanding that the splitting of molecular hydrogen into atomic

Re: [time-nuts] ublox NEO-M8T improved by insulated chamber?

Hi, Jim! On Wed, Nov 8, 2017 at 3:12 AM, jimlux wrote: > > http://www.navipedia.net/index.php/Ionospheric_Delay > has a nice discussion with simple equations to turn TEC into delay, etc. > I've already skimmed this, and it requires a bit more brainpower than I can muster

Re: [time-nuts] ublox NEO-M8T improved by insulated chamber?

> > Envoyé depuis mon appareil mobile Samsung. > > -------- Message d'origine > De : Ole Petter Ronningen <opronnin...@gmail.com> > Date :07/11/2017 15:15 (GMT+01:00) > A : Discussion of precise time and frequency measurement < > time-nuts@febo.com> >

Re: [time-nuts] ublox NEO-M8T improved by insulated chamber?

Hi all Attached is a 24 hour plot of PPS out from a UBlox 6T against a hydrogen maser. From 00:00 the bare receiver board was inside a polystyrene box where it has soaked for many months, at 16:00 I removed the box exposing the board to the airflow in the room, including AC. The box was left off

Re: [time-nuts] I've been thinking about a GPS receiver experiment

I did log the #TIME message for several weeks on an OEMV-3 a while back. The results were a bit suspicious, so I checked with Novatel support - turns out the PPS on the OEMV (and I presume that also holds for OEM4) is derived from L1 only - and the jitter is nothing to brag about. So for

[time-nuts] Outlier detection and removal

Hi, all A reasonably well known method of outlier detection in phase data is to convert to frequency and look for outliers more than k multiples of the Median Absolute Deviation. I believe this is how outlier detection is done in Stable32[1]. I have implemented an approximation to this method -

[time-nuts] (no subject)

Hello I just stumbled across this: https://www.muquans.com/index.php/products/mclock A commercially available cold atom rubidium clock! My apologies if this has already been reported on the list. Ole ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] gLAB PPP noisy clock residuals

> > I did a comparison of a few PPP results some years ago, maybe you saw it > already > http://www.anderswallin.net/2013/12/comparing-gps-ppp-solutions/ Ah, yes I forgot about that! Nice, I'll revisit RTKlib again. > For the web-service running NrCAN, there was an URL API that allows running

[time-nuts] gLAB PPP noisy clock residuals

Hi, all Not sure if this is 100% within scope of the list, but still: I am trying to get some good stability measurements of my hydrogen maser, using GPS L1/L2 and PPP. I collect L1/L2 code and phase observables continously, and process daily RINEX-files with PPP software and IGS corrections.

[time-nuts] LEA-6T effect of position hold

Hi, all The subject of position hold mode in GPS receivers pops up every now and then. Here is a plot that may be of interest to some. Nothing new, but I thought it a nice visualisation of the difference between position hold and "not position hold". I was measuring EFOS 3 against the PPS of a

Re: [time-nuts] Thermal effects on cables

I should have mentioned this in the original post - the measurements were not taken on the same cable length. Beware, and consult paper. Ole On Fri, Jan 13, 2017 at 7:52 AM, Ole Petter Ronningen <opronnin...@gmail.com > wrote: > Hi, all > > The question of phase shifts in cable

[time-nuts] Thermal effects on cables

Hi, all The question of phase shifts in cables pops up every now and then on this list - I stumbled across a good table of measured phase shifts with temperature in different cable types in this paper: http://www.ira.inaf.it/eratec/gothenburg/presentations/ERATEC_2014_PresentationWSchaefer.pdf

Re: [time-nuts] hm H Maser

Add to this ion-pumps (in the case of EFOS type masers 2 every ~2 years), plus substantial tooling (turbomolecular vacuum pump, anyone?) to service the thing - unless you want the manufacturer to do so.. Ole On Tue, Jan 10, 2017 at 11:12 PM, Dr. David Kirkby (Kirkby Microwave Ltd) <

Re: [time-nuts] hm H Maser

Not sure how relevant that particular example is. PHM on Galileo was new science (at least the sapphire loaded cavity), and *very* different reliability engineering. AHM's are nothing new, the science hace been done, the construction is known, down to exact drawings and circuit diagrams. There

Re: [time-nuts] EFOS 3 online

I suspect it is no longer doing 1e-13 at 1 second tau - it was a long drive from Neuchatel, and lots of stuff shifting! Not to mention my less than optimal temperature stability (or lack thereof). But it should still be good enough for a house standard! :) I casually mentioned the difficulty

[time-nuts] EFOS 3 online

Hello Inspired by Corbys post, I thought I'd follow up with putting the telemetry-data from EFOS 3 on the web, for those with any interest in these things. There is also a small picture gallery. Can be found on www.efos3.com. If I got the scheduling right, weekly plots should update every 5

Re: [time-nuts] Trimble UCCM survey results

Possibly the z3801 reports heigh as MSL, whereas the UCCM use some other reference frame. Ole On Tue, Dec 20, 2016 at 7:28 AM, Tom Curlee wrote: > A couple of questions: > I've just started using LH 5.0 with my 2 GPSDO units (Thanks Mark!) - a > Trimble UCCM and a

Re: [time-nuts] Hydrogen maser spin exchange

mention. Essentially a state selector. > Pretty sure that thought will get corrected pretty quickly. > Regards > Paul > WB8TSL > > On Fri, Jun 17, 2016 at 3:33 PM, Ole Petter Ronningen < > opronnin...@gmail.com > > wrote: > > > Hi. Apologies for a long

[time-nuts] Hydrogen maser spin exchange

Hi. Apologies for a long post. I'm trying to read up on the "care and feeding of hydrogen masers". While they are conceptually simple from a distance, there's quite a bit going on in the quantum mechanics department when looked at up close. Somewhat frustratingly, I am not mentally equipped to

Re: [time-nuts] Generating a solid PPS from 10Mhz source

Sounds like a PICDIV is just about right: http://www.leapsecond.com/pic/picdiv.htm Ole On Wed, Jan 13, 2016 at 10:22 AM, Jerome Blaha wrote: > Hey Guys, > > Is there an easy circuit to build that can consistently deliver a 1 PPS > from a 10MHz source with excellent

[time-nuts] Public lecture on atomic and optical clocks

Hello There is a relatively recent (november 2015) public lecture by David Wineland on Youtube, titled "Keeping Better Time: The Era of Optical Atomic Clocks". I thought it an interesting, clear overview for the non-expert. Link: https://youtu.be/LxbkyuzXst4 I searched the archives, but could

Re: [time-nuts] Novatel ProPak-V3 GPSDO

for the GPSDO / > measurement > system. > > This is by no means a knock on the Novatel cards. They are *very* good > devices. The gotcha > is the fact that they need a lot of firmware “unlocks” to do all the good > stuff they are capable of. > With the *full* set of unlocks t

Re: [time-nuts] Novatel ProPak-V3 GPSDO

> quite a long time, and one V3 > > > > On Fri, Dec 25, 2015 at 3:35 AM, Ole Petter Ronningen < > opronnin...@gmail.com > > wrote: > > > Hello > > > > I'm sure many of you have noticed quite a few surplus NOS Novatel OEM-V3 > > L1-only unit

[time-nuts] Novatel ProPak-V3 GPSDO

Hello I'm sure many of you have noticed quite a few surplus NOS Novatel OEM-V3 L1-only units appearing on eBay lately. Reading the firmware manual, it seems the ProPak is capable of steering an external oscillator with the addition of a filtered chargepump circuit. Has anyone made any experiments

Re: [time-nuts] Digital Phasae Lock Loops

Quartzlock makes a couple of interesting digital PLL-modules, marketed specifically as ultra low noise cleanup loops. The datasheets contain a lot of interesting and useful information about the software architecture - not enough that *I* can recreate it, but perhaps someone more skilled than me

Re: [time-nuts] LAN/USB to GP-IB/HP-IP Adapters

I have both a chinese clone 82357b and two NI GPIB-USB-HS. If you will write your own software for aging test-equipment, my experience is that a clean NI solution with GPIB-USB-HS and NI 488.2 is a *lot* less painful than trying to get Agilent GPIB to play nice with the NI software-stack. Speaking

Re: [time-nuts] Troubleshooting Fluke PM6681

battery eventually fails, and then you need to replace it and re-calibrate it. I have the details jotted down, but it seems that this is not your issue. Cheers, Magnus On 08/16/2015 12:20 PM, Ole Petter Ronningen wrote: Hello. I have a Fluke PM6681 that has issues. When I got it, it gave

[time-nuts] Troubleshooting Fluke PM6681

Hello. I have a Fluke PM6681 that has issues. When I got it, it gave results all over the place, but after adjusting the 100Mhz multiplier-chain, it seems to be much better; at least I get std.deviationwell within spec using a split pulse to input A and B, 100 samples. I'd like to get it

Re: [time-nuts] Modified Allan Deviation and counter averaging

*Very* much looking forward to some insight on this method - I've done pretty much the same experiment with an E1740A (48.8ps resolution); trigger from a z3805A PPS, start TI measurement on the first rising edge of the z3805A 10Mhz (on channel 1) following the trigger, stop the TI measurement on

Re: [time-nuts] FTS 8400

Hi, all. The FTS-8400 arrived today, with a manual. I might scan it for posterity, but it seems to be a bit less useful than I hoped for - I figured I might be able to use it as a disciplined oscillator to an external PPS, but it does not look like it is capable of that. Anyway. just though

[time-nuts] Some questions related to time-interval measurements and modulation domain analysis

Hello, all! This will be a long post, my apologies.. A while back I scored a HP E1740A time interval analyser. This unit has a 48.8 pS resolution, which is great, but it can only measure up to 3.2uS with that resolution, which is a bit limiting. It can also store up to 500K readings internally,

[time-nuts] FTS 8400

Hello, all I recently came across a FTS 8400 Satellite Timing Receiver, and while I await delivery, I am trying to dig up some more information about it. I haven't been able to find much on line, but from what little I have found they've been used in some pretty high end setups - which leads me

Re: [time-nuts] 53230A noise floor

Tangetially relevant; I made a patch for TimeLab to use the gap-free frequency measurement-mode for the 53230A, if anyone is interested. On Fri, Apr 3, 2015 at 4:34 PM, Tom Van Baak t...@leapsecond.com wrote: There is probably a good explanation for the ADEV-level in standard (pi-counting?)

Re: [time-nuts] Mini-time lab cost and maintenance

Every timelab needs a time interval counter. I'd say look for a HP 5334B with option 010. I've picked up two from ebay for about USD100 each, and that comes with a decent 18011. After that, watch your cash disappear as you discover a need for faster/better/more accurate instruments, not to mention

Re: [time-nuts] Austron 1250A Tuning tool

Fantastic, just what I needed. A little gentle persuasion with a knife coaxed one of my crappy screwdrivers blade to become long enough (or rather, the handle short enough..) to fit. 5 minute job once I knew what is on the other end. Thank you! OleP ___

Re: [time-nuts] Austron 1250A

Thanks all I decided to replace the batteries, expecting delivery any minute now. Surprisingly expensive to replace those NiCd's.. Anyway, after looking at the schematics a bit, I was able to stop the relay chatter by setting the unit to charge, and holding down the reset switch for a couple of

[time-nuts] Austron 1250A Tuning tool

Hello My 1250A has drifted outside the range of the front panel control, so the coarse adjust needs some fiddling. The manual makes mention of a special tool to be used for this. I don't have the tool, the closest I can get is a 10 bamboo stick that I cunningly liberated from my wifes sushimaking

[time-nuts] KS-24361 adjustable PLL time-constant

I know these has been discussed to death here, so my apologies for that. Also, apologies if this has already been reported; i did not find it in the archives.. It might be of interest to some that it appears that the KS-boxes has an adjustable PLL time constant: :SYST:LANG PFORTH pll_rep start

[time-nuts] GPS position averaging

Hello, all I have a couple of GPSDOs (KS, z3805a) hooked up to a fixed outdoor antenna through an HP 58516 splitter. I notice that when I powercycle the GPSDOs (which I generally try to avoid), the position they come up with differs from time to time in at least the last three digits (and height

[time-nuts] Proper way to manually connect Vfc

Hello, all I've started to build up a little collection of various OCXO's, and measuring various deviations and variances and whatnot. I'm putting them into proper enclosures, but up untill now I've adjusted them simply using the Vref through a reasonably low tempco (20-100ppm/C) multiturn pot,

[time-nuts] Low noise powersupplies

Hello, all I thought it may be of interest to some of the members of this list that TI is selling evaluation modules for some ultra low noise regulators for $20 in their estore, shipping world wide included. The specs looks pretty decent to me, and I've ordered up a couple of boards to use as

[time-nuts] FTS1000A 05818-501 spec's

Hello, all I went a bit overboard on ebay and ended up with a FTS1000A model 05818-501. I've found the datasheet for the FTS1000 on ko4bb's site, but the model numbers does not match up. Does anyone know the spec for this particular model (phasenoise/stability), and if there's reason to suspect