Re: [time-nuts] Capturing a 1PPS signal with a Keysight 53230A

Bob wrote: > Drive the other channel with the pps out of the SRS-725 > Feed the output out the serial port to a terminal program for logging. > > You will see a series of delta time numbers. If you are getting deltas under > 1 us Note also that typically, only one edge of a PPS pulse is held to

Re: [time-nuts] Z3801A recovering

Joe, In a way, the VP Service Note: http://www.synergy-gps.com/images/stories/ShopTalk/vp_service_note.pdf ties into the VP Oncore Startup Note because it is associated with the VP Oncore's Pendulum oscillator. Back in the late nineties, some customers noted that VP Oncore signal strength

Re: [time-nuts] help

Hi A cheap GPS module and any of the nearly infinite number of sub $20 “demo boards” would make short work of looking at the pps, the time string out of the GPS and figuring out when it’s the top of the hour. I doubt it’s over 200 lines of code. I’m sure *somebody* will pop up with an

Re: [time-nuts] GPS position

Hi All of the things we yack about in terms of antenna location and timing, also apply to location and self survey. The gotcha is that they apply to a somewhat greater extent. A timing receiver can be pretty happy with a 30 degree view to the horizon. It’s not perfect, but it can work. For

Re: [time-nuts] GPS position

Nick, Comparing the coordinates from the different units, I'm seeing about an 8 ft spread in latitude and about 3 ft in longitude. The elevation is much worse - about a 30 m spread. All units are on the same antenna and splitter. I used this calculator:

[time-nuts] GPS position

> Sorry, no Thunderbolts. TVB emailed me to ask if I had one, to make > the same suggestion. Lady Heather also works with things like the Trimble Resolution-T and Resoultion SMT timing receivers (latest version includes the RES360). You can get a Resolution SMT on Ebay for $25. I would go with

Re: [time-nuts] Capturing a 1PPS signal with a Keysight 53230A

Hi Ok, basic setup (most of which you have already): Set up the counter in time interval mode. Start on channel 1 and stop on channel 2. Set both channels to DC coupling and whatever impedance works with your pps signal Manually set the trigger level to about 1/2 the zero to peak level of the

Re: [time-nuts] GPS position

I haven’t tried, but if you take two GPS receivers of different manufacturers and feed them the same antenna feed… to what sort of tolerance can you expect their solutions to coincide? I mean, obviously they’re *supposed* to show the same location, but I can imagine that the math can come up

Re: [time-nuts] GPS position

Hi The “real” answer is to beg / borrow / obtain a geodetic receiver and let it run for an hour or ten at your location. Unless you are really out in the middle of nowhere, that will give you a very accurate position. If you don’t have any buddies who are surveyors, they do show up on eBay

Re: [time-nuts] Crazy PPS

On 5/2/2016 8:58 AM, Joseph Gray wrote: After replacing the GPS module in Z3801A #2, I fired it up and let it run. For over an hour, things looked OK, then the PPS TI/s rose dramatically. Later, it started back down, Other than a high HUP, everything else looked good. What would cause this to

Re: [time-nuts] Datum/Symmetricom BC637 series GPS/Timing Cards

I now have a copy of this firmware upgrade courtesy of another list member, and just wanted to say a public thank you. Regards Nigel GM8PZR In February Microsemi announced the release of version 8 software (firmware) for these cards, intended to resolve some problems caused by the GPS

Re: [time-nuts] GPS position

Sorry, no Thunderbolts. TVB emailed me to ask if I had one, to make the same suggestion. Joe Gray W5JG On Mon, May 2, 2016 at 11:38 AM, Mark Sims wrote: > You could try Lady Heather's precision 48 hour survey. It basically does a > weighted average of median filtered fixes

Re: [time-nuts] GPS position

On the topic of benchmarks, I found this official site earlier this morning. http://www.ngs.noaa.gov/CORS-Proxy/NGSDataExplorer/ Joe Gray W5JG On Mon, May 2, 2016 at 1:49 PM, Wes wrote: > Nothing to do with time but... > > Technically speaking, in surveying a bench mark is

Re: [time-nuts] help

> On May 2, 2016, at 9:51 AM, jimlux wrote: > > > The real question is whether "cron" is timely enough. No matter, just write > a script (or python) that reads time in a loop (and you can put a sleep in > there) and pulses the GPIO when needed. > A Raspberry Pi with

Re: [time-nuts] Crazy PPS

Hi Joe, In a case like this, where you're playing around with a GPSDO, you might want to log everything it has to output. Otherwise we play 20 questions about your antenna, your reception, your temperature, your cables, your neighbor, etc... For these receivers I usually send a sys:stat? and

Re: [time-nuts] Datum/Symmetricom BC637 series GPS/Timing Cards

Much to my surprise... It seems my original Symmetricom ID failed as well. Microsemi must have changed out something on their system. I've re-registered. Let's see what happens. On 02-May-16 05:42, GandalfG8--- via time-nuts wrote: > In February Microsemi announced the release

[time-nuts] GPS position

You could try Lady Heather's precision 48 hour survey. It basically does a weighted average of median filtered fixes over 1 hour time intervals. The median filtering automatically throws outliers out of the data.

Re: [time-nuts] GPS position

Nothing to do with time but... Technically speaking, in surveying a bench mark is a vertical control point. In playing with Geocaching I've located bench marks that were placed in the 1930's and never found again (until I did). There were often a hundred feet or more from where the

Re: [time-nuts] help

Here's a possible solution. It's ethernet-connected and will switch a 10A output. It's made for UK use but would probably be fine if you have a 220V supply. It doesn't say whether it tracks NTP, but looking at the specs i'd suggest it's linux inside and can do that.

Re: [time-nuts] Capturing a 1PPS signal with a Keysight 53230A

> * DC > * 50Ohm > * Bandwidth filter enabled DC and 50R is ok. I would not use the filter; you want the fastest edge possible. You forgot to mention the most important setting of all - the trigger voltage. Check the signal at your inputs with a 'scope. I typically use 1.0 VDC, unless the

Re: [time-nuts] help

They're a LED and some current limiting. Some are specced as low as 3V and 10mA but they're optimised for 12-24. I'd definitely use a transistor and at least 5V, especially from something like a Pi or Teensy, which have 3v3 logic levels. My reading is that Bill doesn't want to mess around with

Re: [time-nuts] GPS position

A man with a GPS knows where he is. A man with two GPS' not not sure. I've always wanted to walk my self-survey GPS over to a brass USGS benchmark and see it the GPS matches to benchmark location. OK, I've done this with a hand held GPS and gotten readings within about 10 meters. But before

[time-nuts] Crazy PPS

After replacing the GPS module in Z3801A #2, I fired it up and let it run. For over an hour, things looked OK, then the PPS TI/s rose dramatically. Later, it started back down, Other than a high HUP, everything else looked good. What would cause this to happen?

Re: [time-nuts] help

On 5/2/16 8:24 AM, Nick Sayer via time-nuts wrote: To flesh this out a bit more, on a Raspberry Pi, it would be easy to make a cron job that would pulse a GPIO pin high. They really *want* you to use Python (thus the name), but this is easy to do in just a shell script. First, do this to set

Re: [time-nuts] Capturing a 1PPS signal with a Keysight 53230A

4. With 1PPS you probably want to run it in time-interval mode and measure the phase difference of two clocks: have it start on CH1 with (say) the 1PPS from your microsemi, and stop on CH2 with your uBlox. You should still have it on ext-REF with 10MHz from the Rb-clock. gate time refers to

Re: [time-nuts] GPS position

Since, I assume, you are most interested in time/frequency I recommend you use the position that each device self determined. To verify the 10 Mhz output it is easy to compare one against the other. If you don't have a frequency meter with enough digits, just use a 'scope syncing on one and see if

Re: [time-nuts] help

On 5/2/16 8:24 AM, Nick Sayer via time-nuts wrote: To flesh this out a bit more, on a Raspberry Pi, it would be easy to make a cron job that would pulse a GPIO pin high. They really *want* you to use Python (thus the name), but this is easy to do in just a shell script. First, do this to set

[time-nuts] Datum/Symmetricom BC637 series GPS/Timing Cards

In February Microsemi announced the release of version 8 software (firmware) for these cards, intended to resolve some problems caused by the GPS module, which was at one time anyway a Trimble Ace 3. I have been trying to download this firmware from Microsemi but they no longer accept my

Re: [time-nuts] Fw: Optical transfer of time and frequency

If the dynamics is working for you, yes, you can use something like that. If you have noise, you would like a spreading code such that the correlation in the receiver suppress the noise. MVH Magnus On 05/02/2016 11:14 AM, Michael Wouters wrote: One other possibility occurs to me that might

Re: [time-nuts] GPS position

In message , Joseph Gray writes: >Would using a modern GPS, like a uBlox, and averaging for quite a >while produce acceptable coordinates to manually enter into all of the >GPSDO's? Of course the uBlox would be on the

[time-nuts] Capturing a 1PPS signal with a Keysight 53230A

Hi guys, I'm looking to measure and characterize the 1PPS output of a uBlox MAX M6Q using a Keysight 53230A. Specifically, I'm mostly interested in the period of the signal, how close it is to exactly 1Hz and how that signal changes over time. The Keysight is using the 10Mhz output of a SRS

Re: [time-nuts] help

To flesh this out a bit more, on a Raspberry Pi, it would be easy to make a cron job that would pulse a GPIO pin high. They really *want* you to use Python (thus the name), but this is easy to do in just a shell script. First, do this to set things up: #! /bin/sh GPIO_PIN=9 # pick whatever

Re: [time-nuts] help

On 5/1/16 6:30 PM, Chris Albertson wrote: But are you sure you want SMPTE... Do you have a source already? You don't need GPS or SMPTE if you have an Internet connection. The computer can use a set of NTP servers from the "pool" to get time. The result is good enough that the seed of sound

Re: [time-nuts] help

> Le 2 mai 2016 à 03:14, Chris Albertson a écrit : > > On Sun, May 1, 2016 at 12:26 PM, Bill Baker via time-nuts < > time-nuts@febo.com> wrote: > >> My problem: I'd like some kind of off-the-shelf device that can take the >> time code and switch on or impulse

Re: [time-nuts] Fw: Optical transfer of time and frequency

One other possibility occurs to me that might be doable with surplus gear and sticks to the budget. Instead of using WR, give up on getting time of day and just send a 1 kHz pulse stream in each direction. Each station then measures against its own GPSDO clock using a standard/homebrew TIC and

[time-nuts] GPS position

Now that I have three (maybe four) working GPSDO's, I'd like to set the GPS coordinates the same on all of them. The survey that each one does produces very similar coordinates, but not exactly the same. The Z3801A's have VP's, the Lucent has a UT+. I don't know what is in the 58540A, as the