On Jun 21, 2007, at 1:38 AM, Poul-Henning Kamp wrote: > 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. >
After reading thru this thread and looking at the write-up that was posted at febo it looks like a $100 USD is needed to get my 4501 set- up properly. My question is does anyone have any links for low cost GPS sources to be used for the signal input. TIA -Ron -- Ron Rosson [EMAIL PROTECTED] http://www.oneinsane.net _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
