Hi,
if you're worried about in-band interference, the 23cm HAM radio band is
reasonably close to the L1 GPS frequency. When I was still active in packet
radio back in the days, our digipeater DB0DAR lost an interlink due to
interference with a precision GPS receiver in use by another
On Sonntag, 10. Juli 2022 01:24:49 CEST djl via time-nuts wrote:
> I checked the Hittite/AD part at Mouser, $21 and change. Problem is,
> they have a few, but it is marked obsolete/discontinued. Also, a
> devilish package to work with. . .
For a one-off project, lifetime doesn't really matter,
On Mittwoch, 22. Juni 2022 14:59:29 CEST Dave via time-nuts wrote:
> I am using a NEO-6M to provide a PPS signal for an experiment but I need
> to know when it is locked or not.
>
> Does anyone know if there is a way to find out from either the NMEA data
> stream or via the proprietary protocol
Hi Rich,
I'm using a LEA-M8T in a GPSDO project. I've gathered a bit of experience with
the M8 timing receivers over the past two or three years.
Both timepulse outputs can be programmed to any frequency and duty cycle you
like, 10kHz is certainly not a problem. However, some things to
On Samstag, 14. Mai 2022 18:43:13 CEST Carsten Andrich wrote:
> However, even for the 2^16 samples used by the CCRMA snippet, the filter
> slope rolls off too quickly. I've attached its frequency response. It
> exhibits a little wobbly 1/f power slope over 3 orders of magnitude, but
> it's
On Dienstag, 3. Mai 2022 22:08:49 CEST Magnus Danielson via time-nuts wrote:
> Dear Matthias,
>
> Notice that 1/f is power-spectrum density, straight filter will give you
> 1/f^2 in power-spectrum, just as an integration slope.
>
> One approach to flicker filter is an IIR filter with the
Dear list members,
My DIY GPSDO has a rather well defined dependence to the environmental
temperature, which correlates almost linearly with a frequency shift of the
OCXO. However, at times I see the error against the GNSS reference increasing
with its case temperature not warranting such
on
Leapsecond.com are enough for now.
Regards,
Matthias
On Dienstag, 3. Mai 2022 22:08:49 CEST Magnus Danielson via time-nuts wrote:
> Dear Matthias,
>
> On 2022-05-03 10:57, Matthias Welwarsky wrote:
> > Dear all,
> >
> > thanks for your kind comments, corrections and
Dear all,
I'm trying to come up with a reasonably simple model for an OCXO that I can
parametrize to experiment with a GPSDO simulator. For now I have the following
matlab function that "somewhat" does what I think is reasonable, but I would
like a reality check.
This is the matlab code:
On Dienstag, 12. April 2022 00:52:42 CEST Magnus Danielson via time-nuts
wrote:
> A trivial state-space Kalman would have phase and frequency. Assuming
> you can estimate the phase and frequency noise of both the incoming
> signal and the steered oscillator, it's a trivial exercise. It's
>
On Donnerstag, 21. April 2022 13:48:42 CEST Markus Kleinhenz via time-nuts
wrote:
> Hello Matthias,
>
> Could you explain further how enabled GLONASS messed things up for you?
Noticeably more transients in the phase error. Phase jumps of 15ns or more.
Since then I only enable GPS and Galileo,
On Samstag, 16. April 2022 17:55:17 CEST John Ackermann N8UR wrote:
> Finally, it looks like you're comparing the raw PPS with an oscillator
> that is steered by that same PPS. I have to think their correlation
> could lead to possible and unpredictable errors. It would be better to
> have
On Montag, 11. April 2022 11:15:57 CEST Poul-Henning Kamp wrote:
>
>
> Markus Kleinhenz via time-nuts writes:
> > But I think i got some pointers that can put you on your path.
>
> One (always?) overlooked metric, is the frequency spectrum of the
> zero-crossings, of the phase
On Sonntag, 20. Februar 2022 09:41:09 CET Hal Murray wrote:
> kb...@n1k.org said:
> > Can you build this or that from scratch? Sure you can. Being sure that it
> > does indeed work correctly .. not so easy.
>
> Let's change the discussion a bit. Assuming I have a GPSDO, home built or
> eBay, how
On Dienstag, 15. Februar 2022 08:10:12 CET Darren Freeman wrote:
> On one of my units, I had to manually run the lamp heater to a higher
> than normal temperature, before it would light. (With a thermocouple,
> it's best to use some heatsink grease, otherwise the readings can be a
> long way off.)
On Samstag, 5. Februar 2022 10:48:57 CET Julien Goodwin wrote:
> I /think/ it's using more power than it did before (right around 20W at
> total cold, dipping to 10W after a while), although silly me didn't make
> a note of it, but even after 30 minutes it's not locking.
The power starting high
A couple of things to check:
The FRK has a separate power supply pin for the heating elements. Be sure to
connect it.
If the lamp still doesn't light up, check the temperature of the lamp housing.
I'm afraid this won't be easy without disassembling the unit.
If the temperatures are correct,
t; day
> >
> > > or so.
> > >
> > > When I'm doing something requiring the best frequency accuracy, I keep
> >
> > the
> >
> > > 'scope display
> > > running while I'm doing the serious work, and note the frequency error
> > > of
Hi,
a Rb will not be long-term accurate. I'd trust a GPSDO to be long-term
accurate. A hundreds-of-Hz offset between the LPRO and the GPSDO certainly
points into the direction of the LPRO being off the mark.
When you adjust the LPRO, be sure to give it ample time to stabilize.
BR,
Matthias
Dear all,
When the availability of some surplus Ublox M8T modules was announced, I
ordered a few of them and started designing a small breakout board for them.
The design meanwhile had a little cool-down period and matured somewhat. Since
I realized that for most people it can be quite
On Donnerstag, 4. Februar 2021 11:20:23 CET Avamander wrote:
> Hi,
>
> I was wondering if anyone here has replaced the 54 MHz oscillator on the
> Raspberry Pi 4 with a GNSS-disciplined rubidium standard? An overkill
> upgrade, but is technically doable? What hardware would it take in addition
>
Hi,
in case anyone is looking for buying another Rb standard, the seller
"techworldnetworks" on ebay has listed three LPRO-101 "for parts", because
they "appears to have been opened(No bottom screws) and may not currently work
properly". Well...
I'm not interested due to cost of international
Hi,
On Montag, 11. Januar 2021 23:32:24 CET Nigel gm8pzr via time-nuts wrote:
> Noticed Bluegirls changing her listing based on Nigel's false information.
Well, the change to the power supply voltage is certainly correct. The antenna
supply rating is at least safe now. It might be OK to feed 5V
On Montag, 11. Januar 2021 15:53:30 CET paul swed wrote:
> With respect to the cut boards they are about 5 layers and some of the
> layers are shorted by the cut. Perhaps sanding them down would allow the
> boards to be used directly. My luck at popping the module off the board has
> not been very
On Samstag, 9. Januar 2021 23:38:35 CET Nigel gm8pzr via time-nuts wrote:
> I've dealt with this seller before, always been very happy with the results,
> and agreed a price on three such modules which arrived just before
> Christmas, for reference this particular Ebay ID was 333619130232, and
>
and the output is not quite reaching 2.5V. That is
not bad but not as fast as I'd like. I'm thinking of reducing R16/R17 to 68
Ohm to get the impedance closer to 50 Ohm.
Best regards,
Matthias
On Mittwoch, 30. Dezember 2020 17:56:37 CET Matthias Welwarsky wrote:
> Quick heads-up for everyone who might h
Quick heads-up for everyone who might have ordered the breakout board based on
design files I uploaded to github before Dec. 28th.
As Peter Bell found out, the voltage divider that provides VDD_USB to the LEA
module is not adequate, the impedance is way too high and since the current
drawn by
On Dienstag, 15. Dezember 2020 19:22:14 CET paul swed wrote:
> Hello to the group Nigel is correct the way the schematic is drawn the
> Regulator will feed the battery and most likely cause it to burst.
> It should be 1 diode in series with the regulator and 1 in series with the
> battery so that
On Dienstag, 15. Dezember 2020 13:57:48 CET Matthias Welwarsky wrote:
> Time-nuts,
>
> I've updated the repository on github with the latest design files. The
> breakout board is now final as far as I'm concerned.
Common wisdom: nothing is ever "final". After some off-list
On Dienstag, 15. Dezember 2020 14:21:07 CET Peter Reilley wrote:
> May I suggest not populating the DIP header. If it is put on top of
> the board then that prevents it from being plugged into another
> board, the SMA connectors get in the way.
No worries, the assembly process, if done by
On Samstag, 12. Dezember 2020 14:40:11 CET Bob kb8tq wrote:
> Hi
>
> If you are going to drive much with the timepulse output, you will need to
> buffer it. This is true for just about any practical length of coax. It also
> applies to other cables once they get past the “few inches” range.
>
>
> In meantime I will continue working with my good old Thunderbolt.
>
> Many thanks to everybody
> and good and healthy Xmas Time
> and good luck for all your projects!
>
> Arnold, DK2WT
>
> Am 10.12.2020 um 10:04 schrieb Matthias Welwarsky:
> > Dear all,
>
Dear all,
If you go shopping for existing breakout boards:
The ebay listing is for the *LEA-M8T*. It is mechanically and electrically
different from the *NEO-M8T*.
BR,
Matthias
On Montag, 7. Dezember 2020 14:25:35 CET ew via time-nuts wrote:
> With not much happening on Ublox 9T I went back
On Mittwoch, 9. Dezember 2020 23:58:51 CET Bob kb8tq wrote:
> One note: JLPCB is the only “fab + assembly” outfit I’ve tried. Their boards
> are no better / no worse than a lot of other board fab outfits. I have no
> idea how they compare to other assembly houses. My selection criteria: “
> are
nal you need to break out
3(4) parts for the power supply (LDO)
USB needs just a few more parts, two resistors, a protection chip and a
receptacle.
>
> Philip
>
> On Wed, Dec 9, 2020 at 3:27 PM Matthias Welwarsky
>
> wrote:
> > On Mittwoch, 9. Dezember 2020 14:57:55 CET Bob
On Mittwoch, 9. Dezember 2020 14:57:55 CET Bob kb8tq wrote:
> Hi
>
> I think the key point is:
>
> *IF* somebody wants to do a layout using the M8T, Bert already *has* a
> “known good” PCB layout footprint in his inventory of useful stuff. Since
> the uBlox is a really odd part, you aren’t going
Joe,
I mentioned those spikes in an earlier, private email as well, I think Bob is
correct, there's something going on with the sawtooth correction.
Since you're already reading the quantization error correction data from the
Ublox TIM_TP message, you might want to try "digitally" applying it.
B h/w both had equal noise.
I don't think this is the deciding factor. It's more that the noise in the two
channels is contains too much information. I'm actually surprised that there
is an improvement at all, with so many inputs to the measurement system being
coherent.
>
> /
16MHz reference clock
would be rather unpractical...
>
> John
>
>
> On 10/7/20 2:29 PM, Attila Kinali wrote:
> > On Sat, 03 Oct 2020 10:37:59 +0200
> >
> > Matthias Welwarsky wrote:
> >> When I started to look more into the software side of the TI
orrelation for cal1/cal2.
>
> John
>
>
> On 10/3/20 4:37 AM, Matthias Welwarsky wrote:
> > Dear all,
> >
> > When I started to look more into the software side of the TICC and
> > especially the ominous "time dilation" parameter, I set up an
On Donnerstag, 1. Oktober 2020 01:20:26 CEST Bob kb8tq wrote:
> Hi
>
> The 53131 RS232 thinks it is talking to a printer. You need to enable that
> on the sub menu *and* then restart ( = power cycle ) the counter. Once it
> is turned on, you can muck with the serial parameters to get them to line
Dear all,
I've been spending a lot of time with the TAPR TICC recently and been getting
to know the instrument better. I have a question for those of you that have
used or are using the TAPR TICC for any kind of measurements:
My setup typically involves a reference clock source for the TICC,
On Montag, 28. September 2020 04:19:12 CEST Stewart Cobb wrote:
> I have a Symmetricom* XPRO rubidium which appears to be reaching its end of
> life. The very sparse manual says that it sets a "service" flag when the
> lamp voltage reaches 600 mV. When I got it, that parameter was at about
> 540.
On Donnerstag, 24. September 2020 02:20:50 CEST Forrest Christian (List
Account) wrote:
> I'm hoping some of the list are familiar with the newer currently-available
> oscillators available from the distributors.
Not really familiar, but I've been looking for a small 5V 10MHz OCXO myself
and
On Donnerstag, 3. September 2020 09:46:23 CEST Matthias Welwarsky wrote:
> Hello, fellow time-nuts.
>
> finishing the next PCB revision of my GPSDO cape project, after assembling
> some components that JLCPCB SMT service doesn't stock I did a test run to
> compare it to the pr
ppen,
while watching the phase only shows what has already happened. And knowing
what's about to happen is always very favorable in control theory.
>
> Bob
>
> > On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky
> > wrote:
> >
> > Kevin,
> >
> > how
t;
> Thanks
> Kevin
>
> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote:
> > On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote:
> >> Guess my image didn't make it, I will add it as an attachment this time.
> >
> > The temperature curve
On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote:
> Guess my image didn't make it, I will add it as an attachment this time.
The temperature curve seems to show some correlation to what is happening with
the DAC. Seems that the DAC and OSC jumps are mostly during periods of
On Donnerstag, 10. September 2020 16:14:45 CEST Jim Harman wrote:
> I recently purchased an LPRO rubidium from the auction site. The mounting
> surface is covered with a thin soft, dry light blue material with a sheet
> of brownish plastic film underneath. I assume this is the remains of an
>
dates on the bottom of the graph. This is around 6
> >> months of worth of drift. Small tics are 7 days apart, major tics 3
> >> weeks...
> >>
> >> Hopefully this helps!
> >>
> >> Dan
> >>
> >> On 9/4/2020 12:00 PM, time-nuts-requ...@
much I can do. I'll give it another week or two waiting for a sign of
deceleration. If it doesn't happen, I'll scrap it.
Regards,
Matthias
>
> Bob
>
> > On Sep 4, 2020, at 2:50 AM, Matthias Welwarsky
> > wrote:
> >
> > Hi,
> >
> > I mentioned in a pr
Hi,
I mentioned in a previous email that I seem to have picked a particularly bad
(broken?) OCXO for GPSDO testing. It drifts at a very high rate, from the DAC
graph I calculate it is around -4e-4 Hz/hour. It's been on for about 1 week
now and the drift doesn't seem to come down, or maybe just
Hi,
since I'm using the MV89A timebase of my counter for all measurements, this
should provide a possibility to also evaluate the stability of that timebase,
shouldn't it?
When I measure a GPSDO, while it is locked the long term stability will be as
good as the GPS clock. Therefore, all drift
Hello, fellow time-nuts.
finishing the next PCB revision of my GPSDO cape project, after assembling
some components that JLCPCB SMT service doesn't stock I did a test run to
compare it to the previous revision. The measurement setup is identical to my
previous test, 53131A with MV89A OCXO,
sinking in mind, but perhaps there is an implicit expectation
> >
> > of convection cooling at least to keep it manageable ?
> >
> >
> > Any idea what case temperature you're seeing @Richard ?
> >
> >
> >
> >
> > Cheers,
> &g
On Dienstag, 1. September 2020 07:15:34 CEST Richard Katsch wrote:
> Hello All,
> I have acquired a Quartzlock E10-MRX Rb 10 MHz standard. It appears to lock
> and produce a nice sine wave that stays in phase with my Trimble Tbolt for
> a time which exceeds my attention span!!!
> It does however
On Mittwoch, 26. August 2020 18:46:59 CEST Hans Jørgen Eriksen wrote:
> Just got my hands on a HP 53310A Modulation Domain Analyzer (with option
> 031) As it doesn’t have option 010 – OCXO, I want to get hold of "the best
> OCXO" and either build it into my house reference or into the back of the
On Mittwoch, 12. August 2020 13:23:57 CEST Tobias Pluess wrote:
> On the picture `gpsdo_180_210.png` one can see the last 30 hours of my
> measured data. During this time, the DAC value need to change only by 9
> counts. I think the DAC value has a slight trend to go lower and lower,
> this is
On Samstag, 25. Juli 2020 14:16:23 CEST John Miles wrote:
> > I've been trying to figure out how the error estimates (error bars) in the
> > XDEV traces in TimeLab are computed. The status bar says " +/- sigma /
>
> sqrt(n/
>
> > m)", obviously "n" is the number of values in the bin for the
Hi,
I've been trying to figure out how the error estimates (error bars) in the
XDEV traces in TimeLab are computed. The status bar says " +/- sigma / sqrt(n/
m)", obviously "n" is the number of values in the bin for the computed tau,
but what is "m"? It cannot be smaller than "n" as the error
t so badly with my own
design.
I logged two traces of the Trimble, one with the 53131A in frequency mode, one
with a TAPR TICC in timestamp mode. Reference again the upgraded timebase of
the 53131A.
See the attached graphs.
BR,
Matthias
On Mittwoch, 15. Juli 2020 18:33:08 CEST Matthias Welwa
Dear all,
I recently acquired a 53131A counter and upgraded it with an OXCO timebase. I
decided to test it out a bit to see what results I could be expecting from it.
So I hooked up two of my DiY GPSDOs to hopefully get some actual data instead
of running DAC value series through MDEV and
On Sonntag, 12. Juli 2020 16:15:20 CEST Hal Murray wrote:
> Don't forget hanging bridges. I don't know of any NTP software that knows
> about them.
If you're referring to the "sawtooth" on the 1PPS from the GPS, the NTP
software shouldn't need to know. It's for whoever provides the PPS
On Sonntag, 12. Juli 2020 12:35:54 CEST Trent Piepho wrote:
> That interrupt line does not go straight to the processor. It goes to
> an interrupt controller, such as the ARM GIC or a proprietary
> controller. The AM3358 uses a TI controller. This controller deals
> with priority of interrupts,
On Samstag, 4. Juli 2020 16:49:11 CEST David J Taylor via time-nuts wrote:
> Matthias, my feeling is that if you want a precision source, neither BB not
> the RPi is a good solution. Maybe with all the tweak you mentioned the BB
> approaches precision (for some values of precision). I see the
On Samstag, 4. Juli 2020 11:30:01 CEST David J Taylor via time-nuts wrote:
> From: Matthias Welwarsky
> []
> Forgive me chiming in with a recommendation: Drop the Raspberry Pi and get a
> Beaglebone Black instead. It is the much better platform for timekeeping
> experiments
On Freitag, 3. Juli 2020 19:44:48 CEST Hal Murray wrote:
> andrew.hanc...@cyrus-consultants.co.uk said:
> > So I cannot use HaTs anymore, so I cobbled together a GPS ublox6 (same
> > module) but using a FT232RL, and connected all the pins correctly, and DCD
> > so I can get PPS.
>
> FT232R is a
On Mittwoch, 17. Juni 2020 22:39:38 CEST Rick Commo wrote:
> I was given a Datum 102500-001 Rubidium standard today. Searcing the Web
> for a manual for this particular model yielded nothing but I did run across
> a manual in PDF form for their LPRO unit. I read through and suspect that
> it
On Montag, 8. Juni 2020 12:00:57 CEST David J Taylor via time-nuts wrote:
> In Lady Heather, it would be useful to sort satellites by dBc. I can't see
> a way to do this. Perhaps clicking on one of the table headings (e.g. dBc,
> PRN AZ EL etc.) could enable that column to be sorted?
>
>
On Dienstag, 12. Mai 2020 20:53:25 CEST Gerhard Hoffmann wrote:
> Ten boards did cost $5 at PCBway, DHL wanted $25 for transport. :-<
> I can publish the Altium Designer project or the Gerber files when the
> 1st ten are used up
> and there has been somewhat more testing. The number of possible
On Dienstag, 12. Mai 2020 11:24:39 CEST Matthias Welwarsky wrote:
> Hi,
>
> The Bourns 3700S series is still available, a 100k Ohm part is this:
> https://www.mouser.de/ProductDetail/Bourns/3700S-1-104L?qs=
> %2Fha2pyFadujnek9uGXX64FiPDt0iEW4%2F27z9APd4XbI%3D[1]
>
Sorry f
Hi,
The Bourns 3700S series is still available, a 100k Ohm part is this:
https://www.mouser.de/ProductDetail/Bourns/3700S-1-104L?qs=
%2Fha2pyFadujnek9uGXX64FiPDt0iEW4%2F27z9APd4XbI%3D[1]
regards,
Matthias
On Dienstag, 12. Mai 2020 11:03:02 CEST tim...@timeok.it wrote:
>Hi everyone,
>
>
On Freitag, 1. Mai 2020 23:42:46 CEST John Bievenour wrote:
> I'm an amateur electronics hobbyist who's still a newbie (especially to
> SMD), so please forgive the basic question.
>
> I recently acquired a FE-5680A that was failing to lock on frequency (pin 3
> never went low). It will power up,
On Montag, 27. April 2020 08:47:45 CEST Hal Murray wrote:
> You could also use the Pi for the microcontroller. There is an API to the
> Kernel timekeeping routines. Try man ntp_adjtime. There are 2 knobs. One
> is to adjust the speed of the clock, aka correct for the drift. The other
> is to
On Freitag, 17. April 2020 16:04:15 CEST Steve - Home wrote:
> There are some Chinese GPSDOs currently on eBay, containing a Symmetricom
> 10MHz oscillator and a Furuno GT-8031 GPS receiver. Has anyone had any
> experience with them? It’s hard to tell from the pictures what the power
>
Some here may find this interesting.
https://youtu.be/eOti3kKWX-c
BR,
Matthias
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On Donnerstag, 19. März 2020 22:17:22 CET Matthias Welwarsky wrote:
> You cannot expect to see the OCXO for small tau if your reference is the
> GPS. The GPS 1PPS jitter and the quantization errors will dominate the ADEV
> graph for small tau. Once you correct the quantization error
On Donnerstag, 19. März 2020 20:32:30 CET Tobias Pluess wrote:
> My recorded data is here:
>
> https://hb9fsx.ch/files/gpsdo/phase.txt
>
> Now I made two plots (here: https://hb9fsx.ch/files/gpsdo/phase.png). The
> upper is the raw phase data, and I also fitted a linear function to it
> (i.e. if
On Montag, 9. März 2020 22:45:28 CET Attila Kinali wrote:
> [1] "Kalman Filtering", by Dan Simon, 2001
> http://aug-roma.wdfiles.com/local--files/progetti:arpinpero/Kalman_filtering
> .pdf
Nice. Particularly, since the chosen example is vehicle cruise control, which
is pretty much what a GPSDO
On Montag, 9. März 2020 22:25:53 CET Attila Kinali wrote:
> On Mon, 09 Mar 2020 13:44:59 +
>
> "Poul-Henning Kamp" wrote:
> > I'm thinking 24h (to minimize GPS periodicities) frequency measurement
> > and adjustment, with a continuous very weak proportional phase adjustment
> > to come with
hing will effectively become a PLL.
BR,
Matthias
>
> Bob
>
> > On Mar 9, 2020, at 9:44 AM, Poul-Henning Kamp wrote:
> >
> >
> >
> > In message <1593455.ijmom2w...@linux-5fgm.suse>, Matthias Welwarsky
writes:
> >>> Backing up a bit
On Montag, 9. März 2020 14:44:59 CET Poul-Henning Kamp wrote:
>
>
> In message <1593455.ijmom2w...@linux-5fgm.suse>, Matthias Welwarsky writes:
> >> Backing up a bit …. the objective is not to minimize overshoot or
> >> keep the loop from oscillat
On Samstag, 7. März 2020 15:35:22 CET Tobias Pluess wrote:
> Hi,
> I am sure it is theoretically possible to find an optimal control loop
> design if you have accurate models of the OCXO and for the behaviour of the
> 1PPS pulse.
> TvB has written a GPSDO simulator which allows to code different
On Sonntag, 8. März 2020 02:08:25 CET Bob kb8tq wrote:
> Hi
>
> Backing up a bit …. the objective is not to minimize overshoot or
> keep the loop from oscillating. The issue here is optimizing the noise
> output of the combination of GPS + OCXO when combined via
> the control loop. It’s a very
Hi,
I've been running my prototype LPRO GPSDO for a couple of days now. I've
attached some plots of key data extracted from the GPSDO log.
RAW GPS TIC , this plot is the the raw measurements of the TIC (phase relation
between GPS 1PPS and 10MHz clock).
Phase error is the basically the same as
On Dienstag, 3. März 2020 18:41:43 CET Attila Kinali wrote:
> On Tue, 03 Mar 2020 14:42:49 +0100
>
> Matthias Welwarsky wrote:
> > In the meantime, I'm thinking of another modification to make: getting rid
> > of the HC390 ripple counter. I think I might be
On Dienstag, 3. März 2020 14:14:37 CET Attila Kinali wrote:
> N'achmittag!
>
> > No heatsink, just a couple of thermal vias into the ground plane and it
> > gets a bit warm, but not more than 35°C (case temperature). I just
> > checked with a thermocouple.
>
> Ok.. I'm surprised. Is the PCB able
uot;, I
found it more in the range +/- 2E-9". It's 4ppb, not 4ppm.
BR,
Matthias
>
> Dana
>
>
> On Mon, Mar 2, 2020 at 3:21 PM Matthias Welwarsky
>
> wrote:
> > On Montag, 2. März 2020 18:32:44 CET Skip Withrow wrote:
> > [...]
> >
> > > The Th
On Montag, 2. März 2020 22:20:48 CET Matthias Welwarsky wrote:
> On Montag, 2. März 2020 18:32:44 CET Skip Withrow wrote:
> With a reasonably stable PPS from a timing receiver, just looking at the DAC
> movements, it should not be a problem to have a MDEV of 1e-14'ish for
> tau=
t lets it’s locked 10MHz
> tick the whole receiver.
Yep, you can do that. Any chance for getting that scheme to work with one of
the stand-alone timing receivers?
>
> /Björn
>
> Sent from my iPhone
>
> > On 2 Mar 2020, at 22:14, Matthias Welwarsky
> > wrote:
>
On Montag, 2. März 2020 18:32:44 CET Skip Withrow wrote:
[...]
> The Thunderbolt DAC steps in 10uV steps IIRC. And it steps its DAC
> voltage every second. With GPS signals jumping around you can still
> (will) end up with poorer short term performance than if the Rb was
> left to its own
On Montag, 2. März 2020 13:14:55 CET Anton Moehammad via time-nuts wrote:
>2. In the UCenter or almost any software
> control for GPS module/receiver we can find data for next pps, why if the
> software can calculate the PPS should be they do not use it to adjust the
> PPS output so the PPS jitter
Hi Attila,
thanks for the review, but I think you're a bit too pessimistic about the
power consumption. But let's get through your points:
On Samstag, 29. Februar 2020 20:08:13 CET Attila Kinali wrote:
>
> First of all, the power supply seems to be under-dimensioned.
> You are going down from
of I guess around 1e-11 (probably slightly worse), 1e-14 is well
below that.
>
> Bob
>
> > On Feb 29, 2020, at 11:45 AM, Matthias Welwarsky
> > wrote:>
> > On Samstag, 29. Februar 2020 16:48:30 CET John Ackermann N8UR wrote:
> >> On 2/29/20 7:40 AM, Matthia
On Samstag, 29. Februar 2020 16:48:30 CET John Ackermann N8UR wrote:
> On 2/29/20 7:40 AM, Matthias Welwarsk wrote:
> > For example, there's the TDC7200 itself. When I tested my design first,
> > the
> > measurements had a distinct relation to temperature, in the order of maybe
> > 300ps/°C, but
On Donnerstag, 27. Februar 2020 16:17:56 CET Tobias Pluess wrote:
> Attached 2 photos and the new schematic!
I'm always wondering about the merit of placing the temperature sensor close
to the OCXO. It's certainly not the only, or maybe not even the dominant
source of temperature related
On Donnerstag, 27. Februar 2020 19:16:22 CET ew via time-nuts wrote:
> Matthias where are you located. I am in the US but I have some partners in
> crime that may be able to help you with AV testingewkeh...@aol.com
>
> Bert Kehren
I'm in Germany.
BR,
Matthias
>
On Donnerstag, 27. Februar 2020 16:17:56 CET Tobias Pluess wrote:
> I will see how well it works. At least I got my PCBs this week, and my
> Mouser order for some components is on the way. I will start with the
> software for the STM32 soon, maybe I will then bother the mailing list
> again a bit
On Mittwoch, 19. Februar 2020 14:50:57 CET wrote:
> Hoi Tobias,
>
> Sorry for the late answer. Took me some time to look at your
> schematics.
>
And I just had a quick look, too: I think you're missing a pull-up resistor
for the TDC7200 INTB signal. Not a huge problem, the built-in pull-up of
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