[ntp:questions] Re: Good GPS for attic?

Brad Knowles brad at stop.mail-abuse.org
Thu Mar 10 08:39:56 UTC 2005

At 6:17 AM +0000 2005-03-10, John Pettitt wrote:

>>      If you want that same level of accuracy and precision in a
>>  commercial unit, you probably won't be able to get it.  If you can,
>>  you'll spend enough money that you could have bought at least one decent
>>  car or made a down payment on a house.
>  That said for $85 you can get a Garmin GPS18 lvc which claims +/- 1us
>  (modulo the stability of your system and the latency of your PPS drivers).

	But the Garmin doesn't have a Rubidium/OCXO/TCXO clock that is 
disciplined by the GPS signal.  Nor does it have the multiple 
outputs, etc... that are typical for commercial bench units.  Or the 
ability to simulate other types of outputs (e.g., at least some 
Meinberg GPS devices can simulate the kind of output you'd see from a 
DCF77 refclock, as well as various other types).  There's a whole 
host of other features that are missing there.

	I would be very interested to learn how the GPS-only aspects of 
the Garmin compare to the Motorola Oncore 12+, or whatever the 
upcoming replacement is.  I'd also be interested to learn how the 
price differs.

Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

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