[time-nuts] Ashtech Z12T

[Bob kb8tq]

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 at 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 at n1k.org> wrote:
> 
> Subject: Re: [time-nuts] Ashtech Z12T
> To: "Discussion of precise time and frequency measurement" <time-nuts at 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 at 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 at lists.febo.com>
>> To: <time-nuts at lists.febo.com>
>> Cc: "JF PICARD" <jfphp at 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 at 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 at 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 at 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 at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.