[time-nuts] Help needed with frequency standard

[Dana Whitlow]

Mark:

I don't have a PPS syncable PRS-10 yet, but will probably be getting one
within a
year or so.  My expectations are not great, however, because I already know
that
the received GPS time has diurnal wiggles to the tune of up to 10's of nsec
p-p.
And I also know that the PRS-10 (and probably all others in its price
class) make
seemingly random frequency "adjustments" on a time scale of just a few
hours.
For a GPS disciplining loop to fix both, it would have to have a loop time
constant
long compared to a day on the one hand, yet a loop time constant of well
under a
day on the other.  It's kind of tough to have one loop with both properties
at once.

Dana


On Tue, Sep 29, 2020 at 1:22 PM Mark Spencer <mark at alignedsolutions.com>
wrote:

> I would be curious to hear from those who have a GPS disciplined PRS 10 in
> their home time labs.   I was never that impressed with the performance of
> one of mine in that configuration from a 10 MHz ADEV perspective (I did try
> making a few parameter changes.) I ended up essentially free running mine
> but would occasionally apply a 1pps signal to mine as means of adjusting
> its output frequency on an as needed basis.
>
> I may try this again with a different PRS10 (the 1pps output on the unit
> in question failed a few years ago but I have a spare that has been
> recently put into service.)   Perhaps the second unit will work better.
>  Both units were obtained via the usual auction site.
>
> Mark Spencer
> mark at alignedsolutions.com
> 604 762 4099
>
> > On Sep 29, 2020, at 8:02 AM, Luiz Alberto Saba <las at intercat.com.br>
> wrote:
> >
> > Hi guys
> >
> >
> > I want a stable & reliable frequency standard.
> >
> > I do NOT have a cesium beam.
> >
> > I DO have a lot of gpsdos and some rubidiums.
> >
> > Since I have one PRS-10 and this device has a 1 pps input, you already
> know what I'm thinking...
> >
> > What I have:
> >
> > Trimble Thunderbolt
> >
> > Trimble UCCM
> >
> > Symmetricom UCCM
> >
> > Samsung UCCM
> >
> > HP 58503A
> >
> > TruePosition
> >
> > Oscilloquartz Star 4+
> >
> > and a little board with a ublox LEA 5T and 1 pps output.
> >
> > Which device is more suitable for disciplining the PRS-10?
> >
> > My gps antenna setup is:
> >
> > Symmetricom 58532A on the top of the water tank of my building with a
> very good sky view.
> >
> > A Raven Industries LA-21-1575-100-T. About 50 m of RG6.
> >
> > A Symmetricom antenna distributor (don't remember the code but is the 4
> outputs one)
> >
> > By the way... Someone knows the delay of the inline amplifier and the
> antenna distributor? (for Lady Heather)
> >
> > Mark Sims is out there reading this list? I'm having problems with LH
> 6.14 and the UCCM units.
> >
> > Any help you can give me will be welcomed.
> >
> >
> > Thanks
> >
> >
> > Luiz Alberto Saba
> >
> > from Santos - São Paulo - Brazil
> >
> >
> >
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