[ntp:questions] Re: Garmin GPS18USB and NTP on Win2k

Brad Knowles brad at stop.mail-abuse.org
Sun Jun 26 03:31:42 UTC 2005

At 6:32 PM -0400 2005-06-25, Richard B. Gilbert wrote:

>  I have not tried it myself but I have read reports the the USB interface
>  is ill suited to timing applications; that the latency is high enough to
>  produce large values of jitter and offsets.

	That plus the fact that the OP is using Windows would easily be 
enough to account for the kinds of problems being described.

>  USB does work well for navigation but I would not use it for timing.

	And I'm not sure that this particular model of GPS device is good 
for timing use even if the USB interface didn't add its own set of 

	This vendor does have other models which don't use USB that are 
known to be at least reasonably decent, but I don't know how much 
internal electronics and stuff that they share with this model.

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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