the 1198c generates DI from the SI Crystals (Not a Problem but different technology) The Widths are based on distance versus frequency coverage.

788ci HD DI model has a single dedicated DI crystal that the Frequency controls the areas of coverage.

Two different types of technologies and differences in how DI is created. Both work great just different processes to get there.

From the tests ive done recently It looks like the down imaging views are slightly crisper, cleaner, and more detailed, when my side imaging beams are set closer in. so if im in 20 feet of water, I started setting my side beams at 25 feet before looking at the DI screen. I believe this possibly changes the pulse width of the sonar beams,(shorter) and allows for faster processing of the data because the sonar return is increased.
Ive also found that contrast seems to be almost a secondary sensitivity, and really makes things pop out, especially in deeper water. you can have your sensitivity maxed on DI, and not see much,m then crank the contrast up, and things start to really show up.

Leanin post,

I have figured out to get the best images or screen shots. Every time when I start off fishing, I will find a piece of structure or bottom contour. I will hit the cursor as if I were setting a way point and freeze the screen, then I will hit the menu button, go to SI enhance, then play with the contrast and sensitivity numbers until I get the best quality picture. As I move locations and the depth and bottom hardness changes, I repeat the process. It makes a world of difference on the details. Most of the lakes up hear have soft mud, stilt, clay and hard clay bottoms and the density of the bottom changes constantly. So you have to play with the numbers as the bottom hardness changes. Let me know if this works for you down there.

You are correct on the DI.
SI is much clearer.

I tried the SI ramge setting adjustment yesterday and didn't see any affect on the DI image quality.

I tried out my new GPS puck yesterday and I'm not sure I understand what I'm seeing. Help me out here.

When navigating to a waypoint, I notice the boat icon doesn't turn with the navigation arrow. The speed up of the arrow, moving as you turn the boat is great but, the boat icon doesn't follow? As I'm moving over a waypoint, very slowly, the boat icon is pointing in a different direction??? What's up with that?
I can live with it but, I don't understand it.
Also, I followed the directions in the manual and when I first got out of the dock, I headed in a straight line and noted the difference in the heading reading and the COG reading within 5 degrees of each other. Then later, I noted that they could be very far apart and changing eratically. Can someone explain this also?
Just curious.

How is your mapping set? North Up, Course Up or Head Up?

is your unit set to true north or magnetic north? I think theres around a 5 degree difference between the two.

Doug, I've tried all three and see no difference when in any of the three.
The manual tells me to be using magnetic north and that the puck compensates for the slight variations between true and magnetic and I don't believe there is a 5 degree variation between the two anywhere in the world but, I could be wrong on that.
I wasn't able to get out yesterday so unable to respond till now.

You can use this address to find the GM angle or declination for your location. In central texas it has my location as a positive 4 degrees.

http://magnetic-declination.com/

Hope that helps

Ron

This is for where I am:

CHARLOTTESVILLE VIRGINIA
Latitude: 38� 1' 45.5" N
Longitude: 78� 28' 36.1" W
Magnetic declination: -9� 42' WEST
Declination is NEGATIVE
Inclination: 65� 37'
Magnetic field strength: 51513.5 nT

In navigation, the difference between true north and magnetic north is known as declination. All U.S. Geological Survey maps print relevant declination information, and the maps are updated every five years to account for shift. Hikers traveling in Northern California, for instance, have to make declination adjustments of roughly 18 degrees.

Okie Bob they found out the world was not flat . did you hear abt it?

should I present you some proof?

Forward
FYI......

This is a correction to an email previously sent out on February 6, 2013 and also on February 15, 2013. The 1197c SI does not support the 360 Imaging product. All other changes of this software release 6.600 are correct.

Humminbird is proud to announce the release of software version 6.600 for 1198c SI, 998c SI, 898c SI and 798ci HD SI products which includes the entire list below.

This release includes the following changes:

Added 360 Imaging operation menus and capabilities
Added iPilotLINK operation menus and capabilities
LakeMaster map coding was updated to work with i-PilotLINK
Fixed an issue where SI data was scrolling at twice the intended rate
Fixed an issue where 2D/DI data was not in sync if 83/200 kHz mode was enabled
Fixed an issue where DI Zoom was not in sync
Fixed SI Sensitivity issues on the 898c SI, 998c SI, 1197c SI, 1198c SI
Fixed an issue where Demonstration Mode OFF would not force normal mode and a connected transducer state
Fixed an issue where rapidly forcing the unit into Simulator Mode could cause the unit to restart
Fixed an issue where Ethernet sonar subscriptions would eventually drop off if the Control Head was booted with Sonar turned Off
Fixed an issue where Ethernet sonar subscriptions would eventually drop off if Sonar was turned Off and then back On multiple times within 60 seconds without a reboot
Fixed an Ethernet issue where the Heading Line ON/OFF setting would not be saved between restarts while subscribed to a remote AS GPS + HS
Removed Universal Sonar II transducer selection option, now users should select dual beam as their selection
Tweaks were made to radar functionality to fix a memory leak
Fixed a bug that caused some models to sometimes skip a view when cycling through views
Locked NMEA output at 4800 baud when enabled
In addition, 6.600 for the 1197c SI supports all of the above except 360 imaging capabilities and menus.

Version 6.570, 6.580 and 6.590 for the 1158c, 1158c DI, 1157c, 958c DI, 958c, 858c DI, 858c, 788ci HD DI, 788ci HD and 778c HD have also been released. The changes on these models excludes the 360 Imaging capabilities along with above mentioned SI adjustments plus a few other differences. Please see your Download Description in your Account for full details.

To insure you have all of these latest updates visit your My Account section now.

Tight Lines!

Humminbird Select
Customer Service Team

I started installing my interlink last night to connect my 997 to my 858. I've run into a possible snag. The interlink comes with 2 choke cables. Do I have to install these choke cables ?? If I have to install the choke cables, can I install them near the interlink or do they have to be plugged into the head unit?

No, you don't have to use them. They are for dealing with RFI if you get it.
You put them at the units if you use them.