Humminbird Side Imaging Forums

Side Imaging Forums => 798c SI => Topic started by: RangerMan on April 09, 2012, 08:38:36 PM

Title: Getting consistant incorrect depth readings
Post by: RangerMan on April 09, 2012, 08:38:36 PM
I have a 798ciHDsi. It works great other that it is reads 5 feet too shallow all the time.  I am running the xducer for it on the trolling motor and that puts it about 1.5 feet under water.  I changed transducers from the standard issue to the XTM 9 SI 180 T with the same result. I can fix the depth reading by adjusting  the depth offset, but that just creates an annoying bar across the top of the screen when in switchfire mode.  I also run a 797 si on the console with its xducer on the transom and it works fine. I have tried running just the bow unit but it did not help.  Both have the same power source. The power cable does not run in parallel with the TM cables for any length. I have not upgraded to the newest of the new software versions yet. Has anyone else had this problem? Thanks.
Title: Re: Getting consistant incorrect depth readings
Post by: Humminbird_Greg on April 10, 2012, 10:30:35 AM
It sounds as if you have the Depth Offset menu on the 798 unit set to -5 feet (or -3.5 feet with the depth of the transducer on the trolling motor).  When you say that you can fix the five foot off readings by adjusting the depth offset menu; are you meaning that the unit shows five feet off when the Depth Offset menu is set to zero?

Can you post a Screen Snapshot of the five foot off readings while in the 2D sonar View please?

I don’t know that this is a software issue but it would help to know what version you are currently running or just upgrade your unit to the current 6.250 version and see if it still happens.

Try swapping your 798 and 797 units around to see if this issue follows the unit or stays with a certain transducer.

Title: Re: Getting consistant incorrect depth readings
Post by: sonar2000 on April 10, 2012, 08:01:29 PM
Make sure the bow is on the same plane as the transom..
some times they tilt up a little bit and cause the beam to be a bit sideways..

chuck
Title: Re: Getting consistant incorrect depth readings
Post by: RangerMan on April 10, 2012, 08:49:04 PM
Thanks for the replys fellas. To answer your question Greg, Yes when the depth offset is at 0 it reads 5 feet to shallow. I have to set it at +3.5 feet to get correct bottom readings give or take a few inches. Which is not really a problem except for that red bar that comes across the top third of the screen when in really shallow water, say 12 feet or less. The software I'm running now is 5.450. I wasn't aware of a new update until yesterday after checking out HB's website. I will update asap. If I remember correctly, I took the unit out on the water when it was fresh out of the box and it worked good. Then I updated the software shortly after that.  That may be the whole problem.  I am away from home right now so I cant post a screen shot until Thursday or Friday.  I dont think its an angle problem with the boat. It sits very level in the water with one or even two people on the bow. After all, it is a Ranger. Thanks again guys.
Title: Re: Getting consistant incorrect depth readings
Post by: sonar2000 on April 11, 2012, 08:49:42 AM
good boat Rangerman.  Should sit level.....
The updates are on this forum under downloads.
2 cautions.
1) only put the download on the sd card by itsself.
2) power on, restore defaults, power off, insert sd card, power on and let it go thru updating, restore defaults, power off and remove cards. Power on  and set your customized menus..dont forget to set advanced mode,
Dont do any waypoint updating until you have tried the unit.

Chuck
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