[ntp:questions] how do you like the Trimble Resolution T

Chris Albertson albertson.chris at gmail.com
Wed Feb 29 17:00:57 UTC 2012

On Wed, Feb 29, 2012 at 8:58 AM, Chris Albertson
<albertson.chris at gmail.com> wrote:
> On Wed, Feb 29, 2012 at 7:56 AM, unruh <unruh at invalid.ca> wrote:
>>>> Timing gpss like the Oncore UT+ sends the known PPS offset as part of
>>>> the serial timestream, telling NTPD (or any other recipient) how
>>>> early/late the pulse actually did arrive.
>>>> This is nice to have if you also have a stabilized clock source for
>>>> your motherboard, along with hw to detect and measure the interrupt
>>>> latency, i.e. the time between the PPS pulse and when the OS driver
>>>> wakes up and notices it.

 I think the UT+ is the best for the money.  Normally they are under
$20 and have very good performance.  Buy two and keep one as a spare.
Certainly much better than anything made by Garmin and almost right up
there with a Trimble timing GPS.    Of course the newer Oncores are
even better, but NTP will never notice.   What ever you get make sure
is is a "timing" and NOT an navigation GPS.  There is quite a

But the biggest thing BY FAR is the the computer have a REAL RS232
port and not USB.   Other wise all of this accuracy is wasted.   I'd
say the port matters more than the brand of GPS.    The next thing in
order of what matters is your antenna setup.  It is MUCH better if it
is out doors and can see the entire sky.   How hard can it be to run a
few feet of wire?   And then the OS.  If you are setting up a ntp
server run either BSD or Linux.   Both work much better then anything

I'd go as far as to say that if you can't set up a GPS "correctly" why
bother?   You may as well just use Internet pool servers.   The pool
servers will give you time to within a few milliseconds.   Only use
GPS if either (1) you don't have an Internet connection or (2)
milliseconds are not good enough and you want micro seconds.
Don't use an indoor antenna with a USB connection will if the goal is

Chris Albertson
Redondo Beach, California

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