I had some trouble on my GT-11 on Tuesday when my max speeds were not showing on the display. I turned the GPS on several minutes before sailing so I assumed it had a lock on the sats. A squall came through and I hit the water for a 3km downwind run only to find at the end of it that no peak speed had been registered. I restarted the GPS and it was still only working occasionaly. I was stationary for a extended periods(between runs) of time with the gps in full view of the sats. When I checked the SD card there was only 1 file from the day(30/6) when there should have been 2 and the 1 that did read only had 217 points. I have come to the conclusion that satelite reception may have been an issue as on the bits of track I do have(after I reset) the sats are down to 4 & 5, although I sailed the same spot the day before with 10 or so sats showing up in the track.

I have tried to import the data from the logger(in an attempt to find the missing data, if there is any) using GPSresults & navilink but come up with an invalid command line error(ERROR_INVALID_CMD). In the GPSresults import there was also a "Track-Start could not be found" message.
Do any gurus have any idea about the command line error and if it is a software glitch or should I give up trying to salvage data that may not exist?

I can clone the data from the logger as a *.dat file but it took several attempts to get 100% Can I get anything from this data independent of the GPS?

I have obviously tried saving the data to the sd card but this is the same size file that is already present on the card with 217 pts, I was wondering if data may not be copied across if a minimum number of sats are not present?

I wouldn't normally be so desperate to recover the data but in this case I thought I may have bettered my NM PB.

Kimba did U try to rewrite firmware again
maybe is some software (firmware) error, so try to put firmware again
(even if is the same version)
that help me few times on garmin 205 forerunner, maybe that fix probs in gt also

you have nothing to lose...

Kimba, every now and then these chuck a wobbly like yours just did. No explanation as to why. Mine just didn't write to the card for a session in May this year. I got home and zilch. I did have a data logger file but it was over a few sessions. I then ran a full actual test on the unit, I turned it on outside, and before it got a chance to lock any sats, I walked back inside, then out the front and a walk around the block. It didn't write to the card.
I then did the same thing, and let get a good fix before I set off and it came good, recorded no problems.
Not sure, but I recall something way back when we started that if it cant get a good fix from go, it wont do much. I maybe wrong.
Best guy to email is Time Machine, or Tom at Mt Best, he may be able to shed some light on it.
http://mtbest.net/setting-up-navi-GT31.htm

Thanks for advice mineral & wkcwarrior but I think I am resigned to the fact that I lost satelite reception, or did not have a good lock to start with. I always take a second GPS(garmin 101) but murphys says that the batteries were flat so I left it in the car. The annoying thing is that I had some new lithium batteries for the head cam which I could have used but did not want to waste. I sailed again today and changed to the sat screen and waited for them to lock to be extra sure, seemed to work again. I will get some luck soon I suppose, or get a second Navi!

Geez Kimba that's some bad luck right there.

You know that you did the speeds, but the technology let you down...

I really hope that this never happens to you, or anyone else in the future! Maybe that idea of having two GPS's isn't such a bad idea after all.

Kimba , have you tried just to put the sd card out /in again, it has to come out of gps for some reason, maybe like phone sim cards , bad connections turn gps on and go to menu speed, and then Save to card , this has worked every time any perthsouthsiders have had problems.

Select to expand quote

bigdog said...

Kimba , have you tried just to put the sd card out /in again, it has to come out of gps for some reason, maybe like phone sim cards , bad connections turn gps on and go to menu speed, and then Save to card , this has worked every time any perthsouthsiders have had problems.

or try to reinsert sd card and format it again

be shure that:

Memory Card
LOG SWITCH:__________ON- FIX
MIN SPEED:___________1 KT
NMEA ITEMS:_________SBN 1-SEC
FILE SIZE:____________CARD SIZE

is setted correctly as above