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I usually pull Crankbaits using my Humminbird 999.. This spring I have been spiderigging using my 7 upfront and have found it to be a problem. Any speed less than .5 it is nearly impossible to tell where the under water creeks and such are due to the image on the screen rotating wildly. Above .5 it works ok. Any ideas what is wrong ?
Consumer GPS is accurate to 8-10ft 95% of the time ...
When the boat speed is less than 0.6mph - the boat is not actually moving far enough on the water (greater than 8-10ft) for the GPS to effectively define that the "boat actually moved" - so the boat icon changes to a circle to indicate that the GPS is "waiting" for more defined information that the boat "actually moved past that 8-10ft barrier" ...
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Now, given the fact above about the inherent accuracy/inaccuracy of GPS systems -- And the fact that the HB Chart Defaults to "North Up" any time that the GPS cannot determine Course (example below 0.6mph as defined above)...:
Thus :: if the Chart Orientation is set to "Course Up" or "Head Up" - and the boat speed decreases below 0.6mph (GPS inherent inaccuracy) = the Chart Defaults (spins) to the "North Up" orientation ...
And once the boat speeds up to 0.6mph (GPS accuracy again) the Chart orients back to the user defined setting of "Course Up" or "Head Up"...
This can be confusing when the boat is travelling right at that 0.5-0.6mph variation in speed because the Chart is spinning from its user selected setting (Course Up or Head Up) to Default North Up ...
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To "fix" the spinning Chart (if the boat is going to be traveling at that 0-5-0.6mph barrier) is set the Chart Orientation to North Up (the same as the default Chart setting when GPS cannot determine course) ...
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The AS GPS HS antenna also "fixes" the spinning Chart issue buts it's not a "plug and play" option for HELIX 7 ... It requires some wire spicing ...
http://www.humminbird.com/Category/S...HELIX_EXT_GPS/
Rickie
That's always been a problem of HB. Can't find the course at sloooow trolling spidering rigging speeds. Lowrance does a much better job on this issue. It'll show the correct direction at .1.
BRM
Lowrance uses a GPS filtering algorithm that blends the newest GPS data points with the previous GPS data points into a "probabe course" at slow speeds ...which allows the boat icon to show course at those slow speeds ...Quote:
Originally Posted by BigRiverMarine
The Cumulative Displacement Filter - Source
It is a good thing ...and fairly accurate ...
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HB chooses not to use such GPS filtering algorithms (and they won't tell me why other than their standard "we choose not to guess at our GPS course positioning) ...
Anyone remember "Project HB Donut" ...??
http://www.crappie.com/crappie/fishi...ject-hb-donut/
That ruffled some feathers ... at HB and across all the electronics forums ...
I still have the Donut ... But I've learned how to use it over the years ...
Rickie
rickie, you've gotta have the donut, you need it to go with your coffee :Rofl
I have the same problem with my helix 9, even at 1.5 mph. can't tell where I am or where to go to find my waypoints. never had this problem with my humminbirds before. have to call them this week I guess.
Are you using the internal GPS antenna or an external GPS puck ...??Quote:
Originally Posted by fish k3
Rickie
internal....
Does the unit have a clear view of the sky ... Or is it under a windshield ...??Quote:
Originally Posted by fish k3
Rickie
wide open.
A call to HB may be your best bet ... Issues at 1.5mph is a bit excessive ...Quote:
Originally Posted by fish k3
1-800-633-1468
Rickie