I bought a new gt31 a week ago, my old one died on me.

I've only used the new twice so far, but each time I have had big spikes. One was a peak at 50k (real peak was 37k) and yesterday a spike was 48k (real speed 41k).

The spikes are easy enough to spit and remove, but I was just wondering why thus new gt31 is getting so many spikes. My old gt31 was about three years old and never had any spikes.

Is it just a quality issue or an initial set up issue?

Cheers

All part of the fun. Use KA72 to analyse your tracks. Make it easy.

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sausage said..

from Mt Best website http://mtbest.net/setting-up-navi-GT31.htm

a. LOG SWITCH should be ON-FIX. There is no point to log any data when there is no position fix.

Can't remember if this eliminates those crazy spikes but give it a go if not already set.

Don,t use ON-FIX , use just ON. We've had too many issues with on-fix

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kato said..

sausage said..

from Mt Best website http://mtbest.net/setting-up-navi-GT31.htm

a. LOG SWITCH should be ON-FIX. There is no point to log any data when there is no position fix.

Can't remember if this eliminates those crazy spikes but give it a go if not already set.

Don,t use ON-FIX , use just ON. We've had too many issues with on-fix

Yeah I checked mine this arvo and it is set to just 'ON'. Never had any spikes or crazy jumps that go half way around the globe. Apologies for the bum steer.

I think I might need glasses..... was going through settings again just before and realised that my Log Switch is in fact set to 'ON-FIX' (I'm putting it down to viewing it through the pacqua and zip lock bag). Anyway never had any issues with this setting????

From memory, I think the issue with 'ON-FIX' is that when a fix is lost momentarily, the GPS does not begin logging again immediately as it regains fix. We took the view that we would rather have the data, even if it was wrong, than miss what could be good data. It is usually fairly easy to see the difference if you have all the data.
I don't think this issue resulted in a lot of spikes though, as has been described by the OP.

A wild guess: Check WAAS setting. It should be OFF.

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A wild guess: Check WAAS setting. It should be OFF.

I'll give that a go when I get home. Will I find the WAAS setting in setting?

I have LOG SWITCH set as ON-FIX.

Many thanks:)