[time-nuts] Best Chance GPS module

David J Taylor david-taylor at blueyonder.co.uk
Thu Dec 1 05:14:51 EST 2016


I'm a novice at time issues. I've been gathering info and I think I'm
ready to start asking questions.
A ublox NEO-M8T with an active timing antenna (GPS | GLONASS ?) seems to
be my best chance of being successful at my location.


*    Is there a more suitable GPS module than the ublox NEO-M8T for my
location issues?
*    Can anyone recommend an affordable suitable antenna for GPS & GLONASS?
*    One box or two, for running a local NTP host and receiving the PPS
from a GPS module?
*    Is there a better solution for a micro board than a Rasp Pi with
its USB controlled Ethernet, or the BBB with it's RF issues?
*    What am I not considering that could end up biting me?




* I would avoid a "timing" GPS module.  Experience here shows that such 
modules are much more fussy about getting a good, clean GPS signal 
(understandable, of course) and will likely lose lock in more circumstances 
than a simple "position-only" module.  Almost any GPS with a PPS output will 
be just fine for NTP use, and the u-blox units are some of the best you can 
get.  Use your smartphone to see where the signal is best with a GPS status 

* a simple patch antenna will be just fine, and allows you to place it where 
you like.  You can get these with lead lengths up to 5 metres.

* Use an existing PC for the NTP server.  Linux or Windows will be fine, 
just whatever you have.  With a desktop PC, just be sure it has a real 
serial port and use the Sure GPS board.  Even better, use a Raspberry Pi 
with the Uputronics board, and you can leave that running 24 x 7 at very low 


Unless you are into microsecond accuracy, the Raspberry Pi or BBB will be 

You'll find more information on my Web site.

The one thing you've not stated, though, is what accuracy is acceptable.

SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-taylor at blueyonder.co.uk
Twitter: @gm8arv 

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