[time-nuts] Setting up PRS10 with M12+T GPS

[Azelio Boriani]

>The phase of the PPSOUT and the generated 10 MHz will probably not align
up, >something which is critical to some applications.
Yes, for example the DVB-T SFN requires the PPS and 10MHz phases to be
aligned, better, not to move. This requires to slightly alter the 10MHz to
keep the PPS aligned.

Let me ask Bjorn: did you succeed in aligning the two PRS10? Moreover, what
do you mean by "each other", a scheme like this:



|-------------------------------------------------------------------|
|                                                                   |
|       PRS10A                        PRS10B           |
|--->PPS IN PPS OUT------>PPS IN PPS OUT--|


hoping that the font doesn't mess up the ASCII schematic...


On Wed, May 2, 2012 at 11:07 PM, Magnus Danielson <
magnus at rubidium.dyndns.org> wrote:

> Hi Azelio,
>
> On 05/02/2012 10:30 PM, Azelio Boriani wrote:
>
>> Magnus, you are correct but can I avoid to list our beloved
>> counters/analyzers? The time-nut main tool is the TIC.
>>
>
> Hehe, yes. But you can do great things even with a spare HP5335A for
> instance. It's quite respectable with about 1 ns resolution in this context.
>
> I have not tried using the SIA-3000 for TIC purposes. Just "getting into"
> the machine GPIB-wise is a bit of a challenge.
>
>  Anyway, to correct the PPS input for the PRS10 the hardware approach is a
>> must: so a delay line and a microprocessor are needed. Unless the SRS can
>> develop a suitable software for the PRS10 (an inverted TTL serial line is
>> already present) to read the M12+.
>>
>
> Well, look at the Spectratime SRO-100, which already has that feature.
>
> http://www.spectratime.com/products/isync/gps-disciplined/SRO-100
>
> Architecture-wise it is very similar to the FEI 5680, a 60 MHz VCXO, DDS
> for FLL and then DDS for output. PPS input and output makes you think about
> PRS-10. The PPS input has about 1 ns resolution.
>
> Now, there is a few things which differs from the PRS-10. It move it's
> internal (and later also its output) PPS to align up to the PPS reference.
> It hence does not need an output alignment. This makes the 7,5 MHz clock
> (133 ns cycle) less critical. BTW I do the same in my products. The phase
> of the PPSOUT and the generated 10 MHz will probably not align up,
> something which is critical to some applications.
>
> Also, it can take info from Jupiter-T, OnCore, M12+ and SuperStar II
> receivers for detailed timing info.
>
> Cheers,
> Magnus
>
>
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