Topic: GPS Speed

[Diamondback]

I have the 798 cisi.  When I am trying to troll at around 2.5 mph, my GPS speed will jump from 1 to 3.4 mph.  Is this normal for the GPS to do this?  The lady on the phone with customer service said that anything under 2.5 mph was not accurate with the internal GPS.

[xSilmarilSx]

There's a flaw in the HB GPS algorithm. It lacks a little filtering and you see the speed and position always wandering. It's pretty annoying and useless...

The GPS receiver is not 100% stable.

So I tried connecting a Garmin GPS via the NMEA input and the unit still won't work perfectly. Once in a while, it will glitch and cause spikes in the track log.

My old 718 and 778c (pre HD) worked flawlessly with the same Garmin receiver with the NMEA IN/OUT.

Even though I love my 798CI SI HD, I wouldn't thrust the GPS for it's reliability.
HB engineers should buy a Garmin unit and study a real GPS receiver which locks on satellite faster and stronger with speed accuracy rock solid below 1 mph.

[ITGEEK]

Does the 798 get the GPS signal four times a second?
I remember on my 1197, that the 4.700 update went from
once to four times a second.

Diamondback:Does your unit have a clear view of the sky at all times?
Note: the human body can block GPS signals.
Depending on the angle from the unit to the satellite(s),
and if you are sitting or standing in front of the unit, it may make a difference.

[Diamondback]

I am running a small tiller boat and the unit is mounted towards the side of the boat.

[ITGEEK]

So, when you are looking at your screen, is your body/head
a lot higher than the screen so that it could block one or more
satellites coming in from an angle?

The only other thing I can suggest is to make sure you are running the
newest version of the software.