Re: [time-nuts] How good is the left end of your ADEV curve?

On Wed, Jan 25, 2017 at 1:35 AM, Volker Esper wrote: > What can I do at home, to observe such processes? Or is it way beyond any > imagination to participate in any such experiments? It's not exactly direct observation, but you can participate by joining the Einstein@Home

Re: [time-nuts] New PPB rated TCXO

On Mon, Oct 10, 2016 at 11:53 PM, Poul-Henning Kamp wrote: > I take it they know how to price a gem like that ? > > Any ball-park numbers for us ? I don't have any price info for the "Super-TCXO" but I'd be surprised if it were crazy, SiTime's other products are all pretty

Re: [time-nuts] New PPB rated TCXO

I can attest that that oscillator was a lifesaver recently in a project I was tangentially involved with. They had tried several TCXOs and were plagued with thermal and vibration sensitivity. They dropped in the SiTime and it worked like a charm. Henry On Mon, Oct 10, 2016 at 7:02 PM, Nick

Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board

On Thu, Jun 23, 2016 at 1:09 PM, Nick Sayer via time-nuts wrote: > It all sort of depends on what you call “reasonable.” PNP assembly is a bit > like PCB fab in that there are rather large set-up costs and the per-unit > cost after that is quite low, which favors volume. > >

Re: [time-nuts] GPS altitude somewhat wrong?

Per https://www.topoquest.com/map.php?lat=40.02486=-105.24468=nad27=2=auto=d=zoomin=m the address in your signature is close to the 5250 ft (geoidal) contour. Henry On Wed, Jun 8, 2016 at 3:18 PM, Henry Hallam <he...@pericynthion.org> wrote: > Some of that is probably the differenc

Re: [time-nuts] GPS altitude somewhat wrong?

Some of that is probably the difference between the geoid (what your surveyed maps report height relative to) and the WGS84 ellipsoid (what your GPS reports heights relative to). At Boulder that difference is only about 15 meters, though. Generally with VDOP < 2 and a reasonably modern receiver

Re: [time-nuts] Segal law: freq difference for GPSDO

On Tue, Mar 29, 2016 at 5:48 PM, Vlad wrote: > > I tried to see the 1PPS on my oscilloscope. Here is the series of > screenshots from that experiment: > > https://www.patoka.ca/OCXO/TBvsSL/ >From those scope shots it looks like one or both of the GPSDOs does not have any kind of

Re: [time-nuts] Segal law: freq difference for GPSDO

If you put the PPS outputs of the two GPSDOs into an oscilloscope and trigger on the leading edge of one of them, what does the other look like? Henry On Tue, Mar 29, 2016 at 12:56 PM, Vlad wrote: > > > Hello, > > I am looking for for the advise regarding some strange

Re: [time-nuts] GPS Signal Simulator for GnuRadio

Nice. I threw one together too a few weeks ago: https://github.com/henryhallam/peregrine/commits/sig_gen Henry On Sun, Jun 21, 2015 at 11:33 PM, Attila Kinali att...@kinali.ch wrote: Moin, This just came in trough my feeds. Maybe someone finds it interesting:

Re: [time-nuts] I wish to shorten GPS antenna cable - should I let receiver find the position again?

On Thu, Apr 23, 2015 at 5:03 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: I have an HP 58503A which I am using as a frequency source only - not to tell the time. I want to shorted the antenna cable a bit, but are wondering if I should let the GPS receiver

Re: [time-nuts] serial parsing program

RealTerm is my go-to for this sort of thing on Windows, though it might not be quite as flexible as you'd like. Linux: just mung together a pipeline involving things like xxd, awk, grep.. Henry On Tue, Mar 24, 2015 at 3:22 PM, Cash Olsen radio.kd5...@gmail.com wrote: I'd like to find a program

Re: [time-nuts] June 30 2015 leap second

Such slewing solutions are OK for Google. They wouldn't work well for one of the systems I work with, which uses system time to calculate the position of a LEO satellite for purpose of pointing a 7.6 meter X-band dish. Half a second of error corresponds to a pointing error of 0.5 degrees, well

Re: [time-nuts] June 30 2015 leap second

Correct me if I'm wrong, but as I understand it the tzfile in the tzone package is not used to update the system time - that relies on NTP or similar. Rather, the leap second info in the tzone files is made available for applications to use, primarily for calculating time differences in the past.

Re: [time-nuts] June 30 2015 leap second

The difference between GPS time and UTC (due to leap seconds) is broadcast in the GPS navigation message[1] so all but the most poorly designed GPS modules should take care of it and output the correct UTC time. I'm not going to get into the mess of unix epoch time. Basically, it's not a

Re: [time-nuts] CGSIC: FW: New NANU 2014090

The Swift Navigation Piksi project may be of interest: http://swiftnav.com/piksi.html It has an FPGA for correlation with an ARM Cortex-M3 for tracking loops and navigation. The hardware and ARM firmware is open source, but the FPGA design is closed-source at the moment. However, I don't see

Re: [time-nuts] FYI: Galileo satellite recovered and transmitting navigation signals

It's a global system and modern receivers are already capable of augmenting GPS solutions with measurements from Galileo satellites. Henry On Fri, Dec 5, 2014 at 1:08 PM, Richard Solomon w1...@earthlink.net wrote: Dumb Question Time ... Is the Galileo available in North America or only for

Re: [time-nuts] NPR Story I heard this morning

On Mon, Nov 3, 2014 at 1:18 PM, Mike Feher mfe...@eozinc.com wrote: Anyway, regarding time and gravity, I certainly believe the mathematics of Einstein and others, however, I have a hard time believing that man-made instruments to measure the effects of gravity on time is valid. For example

Re: [time-nuts] Sun Outage

On Thu, Oct 9, 2014 at 11:18 AM, Hal Murray hmur...@megapathdsl.net wrote: What's the beam width of the DirectTV antennas? Does it agree with the 3 or 4 minutes at the back-of-envelope level? DirecTV is a Ku/Ka-band system operating with a 460mm dish antenna. At Ka-band, the 3dB full-width of

Re: [time-nuts] Homemade GPS Receiver

On Fri, Sep 26, 2014 at 8:25 AM, Dr. David Kirkby (Kirkby Microwave Ltd) drkir...@kirkbymicrowave.co.uk wrote: As I say, without stating the properties of the receiving antenna, absolute power levels are not a sensible unit. Indeed, there is an implicit assumption of a ~omnidirectional

Re: [time-nuts] Practical Survey-In Accuracy?

I would call that done. Henry On Sat, Aug 23, 2014 at 4:38 PM, Bob Stewart b...@evoria.net wrote: I've had the LEA-6T sitting in survey-in mode for about 17 hours, and at this point, the u-center software says that the Mean 3D Std Dev is 0.109 meters. Given that my antenna is just a puck

Re: [time-nuts] Caveats on Allan Deviation with ultra stable oscillators

On Fri, May 30, 2014 at 3:24 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote: Always locate your DUTs physically orthogonal to each other. Good point. Of course, if you have more than three in an ensemble then the ensuing hyperdimensional vortex may also cause unexpected cross-coupling. Henry

Re: [time-nuts] HP Z3805A GPSDO Oven Heater Voltages

John, I have a similar unit (probably from the same seller), advertised as an Z3805A upgraded to the features of 58503A, whatever that is supposed to mean. Mine also does not get warm on top, though it appears to be providing a decent 10 MHz output and indicates GPS lock. This is the best

Re: [time-nuts] Beaglebone NTP server

Thanks for all the hints everyone. Lots to try! Henry On Thu, Mar 27, 2014 at 2:41 AM, Iain Young i...@g7iii.net wrote: On 26/03/14 23:18, Brian Lloyd wrote: Well, yeah. I figured that I would run the 1pps from my T-bolt to a GPIO line with appropriate clamping to 3.3V. But if anyone has

Re: [time-nuts] Beaglebone NTP server

Hi Gabs, I have a Z3805A and a Beaglebone, and would like to set up an NTP server for the lab. Any kernel drivers and/or setup hints would be appreciated :) Cheers, Henry On Thu, Jun 20, 2013 at 7:37 PM, Gabs Ricalde gsrica...@gmail.com wrote: On Thu, Jun 20, 2013 at 3:39 AM, Chris Howard

Re: [time-nuts] high (spacial) precision GPS in Kickstarter

I know the Swift Nav guys and they are working on adding various forms of customizable timing inputs and outputs to the Piksi. It's also an open-source project, so it's pretty flexible in that regard. Henry On Sat, Jan 25, 2014 at 4:56 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On

Re: [time-nuts] OT : different Rx and Tx baud rate on same port

You could also consider making a simple gadget with your microcontroller of choice, that presents an interface to the PC of a fixed baud rate (perhaps 115200) and handles the weirdo split rates for the GPS gadget on one or two of its other ports. Henry On Sat, Dec 7, 2013 at 12:18 PM, Hal Murray

Re: [time-nuts] GPSDO for my rubber duckie

The parameters you'll want for conversion between MCAT and mean solar time are given daily in the IERS bulletins: http://hpiers.obspm.fr/eop-pc/products/bulletins/bulletins.html By making use of these you should be able to do much better than the slightly inelegant leap second

Re: [time-nuts] GPS interference and history...

On Thu, Jun 9, 2011 at 2:42 PM, Jim Lux jim...@earthlink.net wrote: GPS orbits are tough from a radiation standpoint too. In particular, the orbits are considerably worse for radiation than GEO, and photovoltaic panels are quite susceptible to radiation. Of course you could put a GNSS in GSO

Re: [time-nuts] light squared test

https://pilotweb.nas.faa.gov/PilotWeb/noticesAction.do?queryType=ALLGPSformatType=DOMESTIC 05/013 (A1221/11) - AIRSPACE GPS IS UNRELIABLE AND MAY BE UNAVAILABLE WITHIN A RADIUS OF 175NM AND CENTERED AT 360709N/1151140W OR THE LOCATION ALSO KNOWN AS THE LAS VOR 324.8 RADIAL AT 2.9 NM FROM THE

Re: [time-nuts] Isolated input oscilloscopes

affordable? The TPS2014 is pricey but it is a real pleasure to use. I haven't run across anything as capable and convenient with isolated inputs and four channels. Running on batteries is also much more useful than I expected it to be, -- Henry Hallam

Re: [time-nuts] GPS antenna info needed

On Wed, Dec 8, 2010 at 6:16 PM, Perry Sandeen sandee...@yahoo.com wrote: My magnetic base hockey puck amplified GPS antenna for my Lucent receiver died. I had purchased it at the Dayton Hamvention so I don’t remember the dealer. I’ve found quite a few sellers on Amazon that are in the USA

Re: [time-nuts] Alternative to GPS?

On Tue, Oct 5, 2010 at 9:04 PM, Neville Michie namic...@gmail.com wrote: Hi, How far could you get passing time around from amateur station to station with a two way handshake system that establishes the instantaneous delay on the two way path and assumes a delay of half that value? A time

Re: [time-nuts] Symmetricom 58535A GPS antenna splitters FS

of these (ePay item 370265750113) and it works well. Joe ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Henry Hallam Sent

Re: [time-nuts] GPS SVN26 / PRN26

Right, but that was over days ago. I think my problem was just some unusually strong multipath. Thanks H On Aug 13, 2010 2:46 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote: On 08/13/2010 09:41 PM, Henry Hallam wrote: Is anyone else having issues with satellite 26 at the moment

[time-nuts] GPS SVN26 / PRN26

Is anyone else having issues with satellite 26 at the moment? Thanks Henry ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

Re: [time-nuts] one-off PC board

up the CAD files that were used to create the PDF, or recreate the layout in Eagle, gEDA, PCB Artist etc and export as Gerber. Or skip the professional board houses and find someone with an etch tank who can help. Henry Hallam ___ time-nuts mailing list

[time-nuts] Buffer / distribution amplifier for TCXO

make the phase noise significantly worse than it already is from the cheap TCXO. Many thanks, Henry Hallam [1] http://www.sige.com/support/download-form.html?dl=DST-00059_SE4120L_Datasheet_Rev_3p5_CYW_May-26-2009.pdf [2] http://global.kyocera.com/prdct/electro/pdf/tcxo/172_e.pdf

Re: [time-nuts] Buffer / distribution amplifier for TCXO

On Wed, Aug 4, 2010 at 1:50 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz wrote: The TCXO output waveform is presumably a clipped sinewave as required by the SE4120L? I posted the waveform at http://www.pericynthion.org/stuff/KT3225_500mV_per_div.jpg Does that count as clipped sine? If not,

Re: [time-nuts] buffer amp transformers...

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Re: [time-nuts] Faulty GPS SAT # 16 on Lady Heather

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Re: [time-nuts] Naval Jelly at home depot 25-35% Phosphoric acid

On Sat, Apr 10, 2010 at 3:44 PM, Bill pha...@wcc.net wrote: I keep at least a couple of gallons of phosphoric acid on hands at all time That can't be good for your skin. Can I suggest some moisturizer instead? ___ time-nuts mailing list --

Re: [time-nuts] Chilean quake shifted Earth's axis. The length of the day shorter by 1.26 microseconds ?

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Re: [time-nuts] Chilean quake shifted Earth's axis. The length of the day shorter by 1.26 microseconds ?

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Re: [time-nuts] Are the days of buying a crystal numbered?

there. -- Henry Hallam Sent from my Laptop ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

Re: [time-nuts] TBolt OCXO replacement

there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Henry Hallam Sent from my Laptop ___ time-nuts mailing list -- time-nuts@febo.com

Re: [time-nuts] No 1 PPS output on a Tbolt

/mailman/listinfo/time-nuts and follow the instructions there. -- Henry Hallam Sent from my Laptop ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow