Hello, Thank you for answer and sorry for delay. As I explained to another answer, purpose is simultaneous view of GPS satellites with the french official time laboratory LNE SYRTE . The corrections factors from the laboratory will enable to get with our high performance cesium about 5. 10-13 . Offset is for us without any utility. You spoke about Novatel boards ; can you please explain more. JFP -------------------------------------------- On Wed, 11/28/18, Bob kb8tq <kb8tq@n1k.org> wrote: Subject: Re: [time-nuts] Ashtech Z12T To: "Discussion of precise time and frequency measurement" <time-nuts@lists.febo.com> Date: Wednesday, November 28, 2018, 11:17 PM Hi Only as an example: One key “feature” of the Z12T is the ability to come up with an absolute offset between a local reference and GPS time. To some degree, that is as much a function of the Z12T being in some sort of “round robin” comparison system as anything else. If that full offset information is part of what you need, that adds even more complexity to the request. A somewhat more modern approach than the Z12T would be one of the new(er) Novatel boards and a bit of custom code running on it. Even there the same problem(s) with calibrating an offset come up. Note that indeed you *can* get a time offset number from a simulator feeding the device. How good that number is (and how much you trust it) is very much a “that depends” sort of thing. Again - right back to the “what are you trying to do?” question. Bob > On Nov 28, 2018, at 4:12 PM, Tom Van Baak <tvb@leapsecond.com> wrote: > > The Z12T is a bit old by now, although some of us own or have used them. Z12 documentation is available on multiple archived Ashtech web sites. Lots of conference / technical papers describing time transfer with Z12T receivers exist. AFAIK a number of national timing labs still use them. > > What is it you're trying to do? Do you own a Z12T and are just looking for spare parts? Or are you looking for modern time transfer via GPS / GNSS? If so, what level of timing accuracy are you looking for? Perhaps you could explain a bit more what your actual request is, or what timing infrastructure you already have running. > > /tvb > > ----- Original Message ----- > From: "JF PICARD via time-nuts" <time-nuts@lists.febo.com> > To: <time-nuts@lists.febo.com> > Cc: "JF PICARD" <jfphp@yahoo.com> > Sent: Wednesday, November 28, 2018 9:33 AM > Subject: [time-nuts] Ashtech Z12T > > >> Hello, >> I am looking for a time transfer system Ashtech Z12T or equivalent. Thank you. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.

Hi Ok, if frequency is the only concern, then a fairly conventional GPSDO would do the job. One of many out there is the FS 740. https://www.thinksrs.com/downloads/pdfs/manuals/FS740m.pdfAnother There are a lot of others. The approach used is normally a very long comparison ( as in weeks). The advantage is that they are pretty much “plug and play” with little intervention required from the user. The Novatel boards https://www.novatel.com/assets/Documents/Papers/OEM7-Receivers-BR-D21517-v1.pdf <https://www.novatel.com/assets/Documents/Papers/OEM7-Receivers-BR-D21517-v1.pdf> are a more “hands on” way to do the task. There would be some software development required on your part to get them going. They would allow more careful control over the exact nature of the comparison. Indeed there are a number of similar devices on the surplus market. The two items above are only a random selection of what’s out there. In the US, NIST used to supply a service (for a charge of course) that set up a comparison system at your location. I do not know if there are similar services available outside the US. Bob > On Dec 3, 2018, at 6:19 AM, JF PICARD via time-nuts <time-nuts@lists.febo.com> wrote: > > Hello, > > Thank you for answer and sorry for delay. As I explained to another answer, purpose is simultaneous view of GPS satellites with the french official time laboratory LNE SYRTE . The corrections factors from the laboratory will enable to get with our high performance cesium about 5. 10-13 . Offset is for us without any utility. > You spoke about Novatel boards ; can you please explain more. > > JFP > > > > > -------------------------------------------- > On Wed, 11/28/18, Bob kb8tq <kb8tq@n1k.org> wrote: > > Subject: Re: [time-nuts] Ashtech Z12T > To: "Discussion of precise time and frequency measurement" <time-nuts@lists.febo.com> > Date: Wednesday, November 28, 2018, 11:17 PM > > Hi > > Only as an example: > > One key “feature” of the Z12T is the > ability to come up with an absolute offset between a local > > reference and GPS time. To some degree, > that is as much a function of the Z12T being in some > sort of “round robin” comparison system as > anything else. If that full offset information is part > of what you need, that adds even more > complexity to the request. > > A somewhat more modern approach than the Z12T > would be one of the new(er) Novatel boards > and a bit of custom code running on it. Even > there the same problem(s) with calibrating an > offset come up. > > Note that indeed you *can* get a time offset > number from a simulator feeding the device. How > good that number is (and how much you trust it) > is very much a “that depends” sort of thing. > Again - right back to the “what are you > trying to do?” question. > > Bob > >> On > Nov 28, 2018, at 4:12 PM, Tom Van Baak <tvb@leapsecond.com> > wrote: >> >> The Z12T > is a bit old by now, although some of us own or have used > them. Z12 documentation is available on multiple archived > Ashtech web sites. Lots of conference / technical papers > describing time transfer with Z12T receivers exist. AFAIK a > number of national timing labs still use them. >> >> What is it > you're trying to do? Do you own a Z12T and are just > looking for spare parts? Or are you looking for modern time > transfer via GPS / GNSS? If so, what level of timing > accuracy are you looking for? Perhaps you could explain a > bit more what your actual request is, or what timing > infrastructure you already have running. >> >> /tvb >> >> ----- Original > Message ----- >> From: "JF PICARD > via time-nuts" <time-nuts@lists.febo.com> >> To: <time-nuts@lists.febo.com> >> Cc: "JF PICARD" <jfphp@yahoo.com> >> Sent: Wednesday, November 28, 2018 9:33 > AM >> Subject: [time-nuts] Ashtech Z12T >> >> >>> Hello, >>> I am > looking for a time transfer system Ashtech Z12T or > equivalent. Thank you. >>> >>> > _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> > >> >> >> > _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.

On Mon, 2018-12-03 at 08:42 -0500, Bob kb8tq wrote: > https://www.thinksrs.com/downloads/pdfs/manuals/FS740m.pdfAnother  https://www.thinksrs.com/downloads/pdfs/manuals/FS740m.pdf

Hi Bob, On 12/3/18 2:42 PM, Bob kb8tq wrote: > Hi > > Ok, if frequency is the only concern, then a fairly conventional GPSDO would do the job. > One of many out there is the FS 740. > > https://www.thinksrs.com/downloads/pdfs/manuals/FS740m.pdfAnother > > There are a lot of others. The approach used is normally a very long comparison ( as in > weeks). The advantage is that they are pretty much “plug and play” with little intervention > required from the user. > > The Novatel boards > > https://www.novatel.com/assets/Documents/Papers/OEM7-Receivers-BR-D21517-v1.pdf <https://www.novatel.com/assets/Documents/Papers/OEM7-Receivers-BR-D21517-v1.pdf> > > are a more “hands on” way to do the task. There would be some software development > required on your part to get them going. They would allow more careful control over the > exact nature of the comparison. > > Indeed there are a number of similar devices on the surplus market. The two items above > are only a random selection of what’s out there. > > In the US, NIST used to supply a service (for a charge of course) that set up a comparison > system at your location. I do not know if there are similar services available outside the US. I've been shown one in a certain German vendors location as they just recently got it. They where proud and happy. I really enjoyed seeing it there, that they took the step. Cheers, Magnus