jamesewood

UPDATE (10-19-08): I am sorry to report that the drift problem has NOT been solved with 2.80/2.80. During today's walk around the same Burke Lake mentioned in the initial post, the track began to drift from its true position after the Vista HXc had been powered on for about an hour. By the time the walk was complete, the average track shift error ran from about 500 feet to almost 900 feet. I have no idea what's causing the problem, but I'm past the point of caring. I've already spent too much time on a device that doesn't work right, so it's back to Amazon in the morning. Time to take another look at DeLorme... Jim Wood.

I am a hardcore backpacker and long-time GPS user, having owned several Garmin units over the years. I recently purchased a Vista HCx from Amazon.com that I immediately upgraded from 2.60/2.60 to 2.70/2.60. On my first test walk of about 5 miles, the drift problem was horrible with portions of the track shifted more than 900 feet from where it should have been. On a couple of subsequent walks, I observed the same kinds of systematic positional errors that developed after the unit had been powered on for a while. After reading some of the posts here, I downgraded the GPS chipset software to 2.50 (keeping the 2.70 unit software) and on at least one test walk (of only about 2 miles), the tracks seemed OK. I should also note that after first noticing the problem, I've been using my trusty Geko 301 as a reference unit, packing the Geko in one shirt pocket and the Vista in the other. I also upload both tracks to various mapping applications (TopoUSA, Google Earth, NG Topo) to help evaluate accuracy. When the new Garmin software became available a couple of days ago, I upgraded to 2.80/2.80. Today, I took my first 8-mile walk since the upgrade around Burke Lake (from the South Run Rec Center) in Northern VA. Much of the trail is situated under fairly heavy tree cover, though the terrain is mostly flat. The Vista track was dead-on. No detectable drift at all. There was also far less "jitter" than the Geko and the track showed no breaks (the Geko recorded about 15 separate track segments, in part because of the foliage, and in part because of the way I carry it). So far, the results appear very promising. I'll report back if I observe any future problems. Jim Wood.