On 6/26/12 2:34 PM, Dave Hart wrote: > On Tue, Jun 26, 2012 at 9:11 PM, Majdi S. Abbas <m...@latt.net> wrote: >> On Tue, Jun 26, 2012 at 04:33:35PM -0400, Robert E. Seastrom wrote: >>> Word around the campfire is that the 18x is jittery compared to the 18. >> >> The 18x is much worse than the 18LVC. Thankfully I still have >> 2 18LVCs... but that said, given the hockey puck design, and that Randy >> already has an antenna, I wouldn't recommend this approach anyway. It's >> really only suitable next to a window, or in a short, wooden structure. > > I agree the Garmin GPS 18x LVC solution is only appropriate near a > window, or in a short wooden structure. David J. Taylor's experience > was the older GPS 18 LVC had a substantially less sensitive receiver, > so that his needed to be mounted outside, while his 18x LVC works > inside. > > The area where 18x LVC underperforms the 18 LVC is the jitter of the > timing of its NMEA output relative to the leading edge of the PPS. > Configured correctly, this should matter very little, and only > transiently at startup where ntpd first uses the NMEA end-of-line > timestamp (possibly fudged to bring it closer to the top of second) to > "number the seconds" before engaging the PPS. I don't recommend > attempting to use any NMEA source without PPS. With it, I don't > understand why Majdi finds the 18x LVC much worse. >
Does anyone use or prefer the 5Hz version of the 18x LVC? ~Seth
