[time-nuts] GPSDO recommendation

Chris Albertson albertson.chris at gmail.com
Wed Oct 12 14:14:07 EDT 2011

On Wed, Oct 12, 2011 at 4:33 AM, Peter Gottlieb <nerd at verizon.net> wrote:
> I would like to get better than 100 uSec so I can get a couple of degrees
> resolution on a synchrophasor project.

You are in luck 100uS is is the range of "easy to do".     Setting up
an NTP servers is a different task from setting up a GPSDXO.   One
does not need a GPSDXO for NTP.  The Thunderbolt is likely the lowest
price GPSDXO but by the time you get an antenna and power suply and
cables you will have spent abot $300.  It will drive an NTP server to
bette than your 100uS requirement.

But you can also buy a Motorola "Oncore" series GPS for as little as
$18 on ebay and it will run NTP just as good as the Thunderbolt.  For
$60 you can buy a brand new Oncore with warenty and tech suport and it
is an order of magnitude better.

If budget is important be sure an look at the cost of electric power.
It is easy to burn up $250 per year of power or even more.   Those
"junker" PCs you find indumpsters are not cheap if you run then 24x7.
  I found a brand new intel Atom powerd machine pays for itself.  Use
a 16GB flash drive or even have it boot off the network and have zero
local storage.

Chris Albertson
Redondo Beach, California

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