Thanks for the info Gary! Why wouldn't you recommend the hat? Anything you'd recommend that is actually purchasable? I can't seem to find any of the Navisys units, and ideally non-USB would be better? On Mon, Jun 14, 2021 at 12:07 PM Gary E. Miller wrote: > Yo Nathan! > > On Mon, 14 Jun 2021 10:40:36 -0700 > Nathan Owens wrote: > > > Sorry, it was MACx-1, but either way, I decided to go for an Adafruit > > Raspberry Pi GPS "Hat", which does 1PPS. > > I do not recommend that HAT. There are much better ones available at > similar prices. > > > I'll setup a raspberry pi > > with RT_PREEMPT > > RT_PREEMPT is overkill. The best you can get on a RasPi is about 54ns > accuracy. Due to the clock granularity of 54ns. > > > and run as a Stratum-1 Clock locally. > > But always have other chimers in your configuration file. > > > This should > > help with better irtt timings. This can be done for <$100 if anyone > > else wants super accurate time. > > For some definition of "super". > > > > Does anyone know if any MAC1-X GPS dongles or anything similar are > > > available anywhere? > > They pop up now and then. Right now GPS parts are hard to find, much > less at good prices. Search for Navisys GR-601W, GR-701W, or GR-801W. > The "W" suffix says it outputs PPS. > > The MAC1-X, or any PPS over USB, will only get you to > 1 milli second > because of the USB. > > RGDS > GARY > --------------------------------------------------------------------------- > Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703 > gem@rellim.com Tel:+1 541 382 8588 > > Veritas liberabit vos. -- Quid est veritas? > "If you can't measure it, you can't improve it." - Lord Kelvin > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink >