[time-nuts] Inexpensive modular gps with 1pps

Hal Murray hmurray at megapathdsl.net
Sat Dec 15 08:19:13 UTC 2012


ghane0 at gmail.com said:
> You mention "low cost units which require you to add a power connector,
> etc".  Could you recommend any that can be bought online?  With RS-232,
> please?

There are two obvious choices.  A bit of googling may find more details 
and/or other boards.

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The new favorite is the Sure demo board.
  http://www.sureelectronics.net/goods.php?id=99
  http://www.sureelectronics.net/goods.php?id=98
(The version with the Bluetooth is cheaper than the one without.  ??)

http://www.satsignal.eu/ntp/Sure-GPS.htm

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The old standby is the Garmin GPS-18x-LVC.  Garmin makes several versions of 
the GPS-18x.
  http://www8.garmin.com/manuals/GPS18x_TechnicalSpecifications.pdf

Be sure to get the LVC version.  The others don't have a PPS.

I got mine from Provantage for roughly $70.
  http://www.provantage.com/garmin-010-00321-36~AGRMO006.htm

Setup info:
  http://time.qnan.org/
  http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm

The GPS-18 (no x) is the older version.  You probably can't find it for sale. 
 It's much less sensitive, but gave much better timing over the serial port.

----------

The GlobalSat MR350P is another option.  It comes with a PS2 connector, but 
you can chop that off.  Their adapter cable doesn't include the PPS.

http://www.usglobalsat.com/p-58-mr-350p-bulkhead.aspx
http://www.usglobalsat.com/store/download/58/mr350p_ds_ug.pdf

That PPS is only 1 uSec wide which may be too narrow for some/most systems to 
capture.

They sell a couple of adapter cables, but none of them support PPS.

You can stretch the PPS signal with the TAPR FatPPS.
  http://www.tapr.org/kits_fatpps.html


-- 
These are my opinions.  I hate spam.






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