Humminbird Side Imaging Forums

Side Imaging Forums => 898c SI => Topic started by: Skot on February 17, 2014, 12:17:10 AM

Title: 898 DI/SI picks up fish better than sonar?
Post by: Skot on February 17, 2014, 12:17:10 AM

Hey guys,

This is my first post here. Please let me know if the attached pics do not work.

I have had my 898cxi si for about 9 months now. I usually fish lakes and constantly looking for schools of Redfin (aka English Perch).

Just wondering why the SI/DI usually picks up fish better than the normal sonar? Do I need to turn the sensitivity up on the normal sonar?

I like to think the finder is right and that there is fish there but my success doesn't reflect what my finder is telling me. Perhaps I would have more success if I had an I-Pilot link that puts me right on top of the fish as it's pretty hard to get the drift right or anchor in the right spot. Should I trust the finder more and be more persistent?

Title: Re: 898 DI/SI picks up fish better than sonar?
Post by: mako101 on February 17, 2014, 04:09:49 AM

Skot, it has to do with sensitivity settings and coverage area, watch this video to understand the coverage area, Humminbird Advanced Sonar - Part 1: Coverage Area (http://www.youtube.com/watch?v=sq74UJaNMSs#ws)

Title: Re: 898 DI/SI picks up fish better than sonar?
Post by: Skot on February 17, 2014, 05:44:39 AM

Thanks mako101,

I do understand the basic principles of the beam types but didn't know about the different widths with down imaging. Perhaps these fish were outside the sonar beam but with so many fish showing on the DI I thought it should have showed more than it has. Next time I'm out I will try adjusting the sensitivity of the sonar to get better returns.

Cheers

Title: Re: 898 DI/SI picks up fish better than sonar?
Post by: rnvinc on February 17, 2014, 07:57:27 AM

What is your "Beam Select" set to under the Sonar tab...??
(This setting controls what echo targets you see in the 2d sonar)...

200kHz is a 20° cone shaped beam...
83kHz  is a 60° cone shaped beam...
200kHz/83kHz is a blended 20°/60° View of both above beams...

Rickie

Title: Re: 898 DI/SI picks up fish better than sonar?
Post by: Humminbird_Greg on February 18, 2014, 09:30:55 AM

Depending on the SI Beam Width menu setting, the unit could be displaying all of the sonar returns in both the left and right Si sonar beams.  This would be significantly wider than your 2D sonar beam coverage area and I would expect to see a lot more “stuff” because of the wider beam width,

Title: Re: 898 DI/SI picks up fish better than sonar?
Post by: Skot on February 25, 2014, 02:26:21 PM

Sorry for the late reply, I have just come back from a fishing trip  :)

I am running 200KHz on the 2D sonar. I am also running the wide beam setting for the SI. Greg may well be on the money.

Thanks for your feed back, very much appreciated.