In message <[EMAIL PROTECTED]>, David Duchscher 
writes:

>That really is sweet.
>
>A couple of questions, if you have the time.  The accuracy requirement
>for our setup is +/- 1 millisecond, do you think the 4501 plus the
>Garmin GPS unit with the standard clock crystal would be able to
>meet that requirement?

No chance.

Any temperature fluctuation will make it dance far more than that.

You need an OCXO (or Rb) to keep it inside 1ms.

>The Garmin GPS 17HVS PPS line has a
>specification of +/- 1 microsecond.  Secondly, do you have an idea
>of what the accuracy of the such a setup would be?

The GPS is actually the less critical component, as long as it has
a decent PPS output.

I have only used Oncore GPS, but with an OCXO that will hold solid
inside 1ms.  With an Rb you get to the point where calibration of
cable-lengths and ethernetchips is your major source of error.

-- 
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