[time-nuts] Z3815 question

[Azelio Boriani]

You can take a look here
http://leapsecond.com/pages/z3801a-efc/
for some insight about the EFC of the Z3801A that should be the same
as the Z3815A.
I think that the Furuno's problem with the 1024 week rollover is not
properly a bug. I should say that the problem is with GPS designers
that used only 10 bits to encode weeks. Anyway, it should be very
interesting if the firmware of the GPS is readable, then the code can
be patched to permanently add 1024 to the week number. Until now I
have not found any reference about Furuno's firmware upload/dowload.

On Wed, Aug 28, 2013 at 3:26 PM, Hui Zhang <ba6it at 163.com> wrote:
> Hello Azelio:
>     Thanks for your reply, about Z3815A auto survey, I found a command can fix it, it's:
>    :GPS:POS:SURV:STAT:POW 0
>    I don't know this command before, the Z3801 manual not include it (I haven't Z3815 manual, but they are kind of similar). When I used SatStat software, I found this command, it does worked.
>   About strange years, my friend told me it's a Furuno GPS's bug, he gave me two url to explain it:
>   http://www.furuno.com.cy/important-notice.html
>   http://www.vk2hmc.net/blog/?p=727#comment-334
>   I will review the old discussion that you talk about.
>   I still not understand how HP define absolute EFC and relative EFC value, I will figure it out.
>
>
> Best regards.
>
>
> Hui Zhang
>
>
>
>
>
>
>
>
> At 2013-08-28 18:14:53,"Azelio Boriani" <azelio.boriani at screen.it> wrote:
>>The Z3815 doesn't store the surveyed location so at every power on it
>>has to survey again. It is supposed you leave it on forever once
>>installed.
>>Strange date: the date reflects the fact that the Furuno GPSes have a
>>1024 weeks rollover correction that was designed in 1993 and past 19
>>years it reverts back. This "bug" was discussed here 2 weeks ago.
>>
>>On Wed, Aug 28, 2013 at 3:30 AM, Hui Zhang <ba6it at 163.com> wrote:
>>> Sorry I forgot a qeustion about EFC, last night when I power on my Z3815A, it had a alarm message is "EFC limit", I use follow command to watch EFC value:
>>>
>>>
>>> Sent: :DIAG:ROSC:EFC:ABS?
>>> reply: +489118
>>>
>>>
>>> Sent: :DIAG:ROSC:EFC:rel?
>>> reply: -6.70809E+000
>>>
>>>
>>> And then, I reboot the device, the alarm disappeared, the EFC value is:
>>> Sent: :DIAG:ROSC:EFC:rel?
>>> reply: +5.78499E-001
>>>
>>>
>>> Sent: :DIAG:ROSC:EFC:ABS?
>>> reply: +494788
>>>
>>> So, I want know what is normal EFC range of Z3815A?
>>>
>>>
>>>
>>>
>>> Hui
>>>
>>>
>>>
>>>
>>>
>>> At 2013-08-28 09:03:40,"Hui Zhang" <ba6it at 163.com> wrote:
>>>>Dear All:
>>>>     I just got a Z3815A GPSDOS, now it working well, but I have few questions:
>>>>
>>>>
>>>>1, Why my Z3815A will do survey everytime at power on? Even its finished survey 100%.
>>>>2, Why its date is 1994 Jun 11? But time is correct.
>>>>3, What's type of antenna connector in back panel?
>>>>
>>>>
>>>>Thanks!
>>>>
>>>>
>>>>Hui
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