Re: ✘NEO-M9N

[Gary E. Miller]

Yo Frank!

On Wed, 12 Feb 2020 17:09:58 -0500
Frank Nicholas <address@hidden> wrote:

> > I think the GNSS 7 is somewhat better:
> > 
> > Price:              $40          $65
> > Antenna Connector:  SMA          u.fl
> > Backup:             Super Cap    battery
> > Berg Pins:          Installed    Just holes
> > Size:               57x25 mm     40x33 mm
> > Mounting holes      No           Yes  
> 
> Site for the product you linked says Backup:  ___Battery Holder +
> Battery___.

My mistake, yes, both are battery.  I was looking at another board at the
time and conflated the two.

> It___s also ___Open Hardware___, released
> under the Creative Commons Attribution Share-Alike 4.0 License.  I
> see +/- for both boards (cost especially for the board you linked).

The schematics for the GNSS 7 are also available.  Not sure the license.

> There is a lot of official/good uBlox documentation linked from the
> Sparkfun uBlox product pages for the board & antenna (see antenna
> mentioned below)

Or, just go to u-blox.com and get the latest rev doc.

> > One takeaway is that GPS antennas do not work well with modern
> > multi-GNSS receivers.  
> 
> This is why I purchased these items with the module:
> Interface Cable RP-SMA to U.FL - WRL-00662 - SparkFun Electronics
I hate that part.

> uBlox brand multi-band
> antenna:  GNSS Multi-Band Magnetic Mount Antenna - 5m (SMA) -

Overkill, you only need an L1/E1/GLONASS antenna.  The L2/L5 in that
antenna adds a lot of cost, not use on the M9N.

> GPS Antenna Ground Plate -

I use old 3.5" HDD platters.  Almost exactly the size that u-blox
recommends, and they do help a tad.

> I hope the antenna is worth the price - $64.95 USD.  With it being a
> uBlox part (ANN-MB-00), it might be available elsewhere for less.

Very few L1/L2/L5 antennas on the market, yet.  So the price is not bad
for what you get.

> For $4.95 USD, it___ll be interesting to see what/if the steel disk
> improves.

You should get, on average, one half extra sat used.

> > For somewhat over $200 the ZED-F9x can approach similar accuracy to
> > survey receivers costing thousands.  But the NEO-M9N will not be in
> > that class.  I'll post plots after I get the NEO-M9N that I orderd.
> 
> The antenna I linked above is ___ Designed for the latest u-blox F9
> platform--including the ZED-F9P module___, with ___L1/L2 dual reception___.

Yes, but you only have L1 in the NEO-M9N.

> Sparkfun has this ZED-F9P module for $219.95 USD:  SparkFun GPS-RTK2
> Board - ZED-F9P (Qwiic) - GPS-15136 - SparkFun Electronics

I have tried other brands of ZED-F9P.  They are nice, but I'll wait for
the price to come down before buying them.

> My main hobby/use for these modules is time keeping.  Does L1 only
> vs. L1/L2 improve time accuracy enough to measure/matter for the cost?

The improvement in PPS is below what you can measure with KPPS.  But
you will see the added location accuracy.

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

            Veritas liberabit vos. -- Quid est veritas?
    "If you can't measure it, you can't improve it." - Lord Kelvin

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