[ntp:questions] site with lots of GPS's and accessories

Alby VA albyva at empire.org
Mon Mar 19 17:25:13 UTC 2012

On Mar 19, 12:12 pm, unruh <un... at invalid.ca> wrote:
> As per my comment. The interrupt processing/clock reading  time on a PC is of the order
> of 1us.
> Note that on the Sure, the process of converting to an RS232 signal
> means that the PPS signal is of the order of 1us accuracy ( the signal
> processors are not the worlds fastests chips)
> The actual PPS signal at the PPS pin has a rise time of about 10ns, and
> the Sure has a normal sawtooth timing signal, so that would indicate a
> few 10s of ns accuracy from the Sure, but the conversion to RS232 washes
> that out (and the interrupt processing time on your computer washes that
> out as well).

  Ack.. You just can't win with time.  lol.  I assume there is no
way to wire up the SureGPS directly from the PPS Pin? You know me,
I'm just on the quest to find accuracy at the cheapest price, because
just makes my head steam to thing of the cost to purchase purpose
devices with rubidium.  :)

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