Topic: 999ci SI Transducer Install

[jbrady2852]

Installing 999ci transducer and wanted to get opinions on placement.  Was thinking opposite side of current transducer install under swim step but concerned about ladder.  Would it be better to install closer to centerline.

[mako9man2]

In my opinion it would be better mounted closer to the boat's center line.  Mounting under the swim ladder just invites someone to use it as a step.  I think your challenge is going to be getting the SI transducer a clear shot across the stern if you intend to leave the existing DI transducer in place.   The DI might block a portion of the SI signal going to the starboard side.  Since you don't have a jack plate mounting the SI aft of the DI isn't really an option.  Hopefully some of the more knowledgeable members will comment.

[jbrady2852]

My plan is to either turn the sonar off and use the navigation/gps and use the 999ci SI or 2D exclusively.  If I was taking out the boat with family and need basic bottom/depth I would put the 788ci head on.  I would not run both sonar units at same time.

[jbrady2852]

If the DI transducer might be in the way of the beam for the SI what about swapping locations.

[Humminbird_Greg]

If you could mount the DI transducer in the indented area of the transom, it would be forwards of the HDSi transducer and would not block any sonar.  They could still cause sonar-to-sonar interference though but your plan is to run one or the other so that won't be a problem.  You could even mount the DI transducer inside-the=hull if you wanted to as it looks to be a fiberglass hull. Then you could mount the HDSi transducer just to the side of the centerline of the boat (leaving enough room so it does not get hit by the motor).  You may have to trim the motor up when using the Si sonar so it does not block any Si sonar to that side.

BTW: you did not install the DI transducer hardware correctly; the two black plastic pieces should snap into each other.

[jbrady2852]

Greg,

I was going to install a quadbeam thru the hull in the bilge area using the T3 switch for high speed.  I fish in the Gulf and would like the extra coverage and side view for structure.  Do you think if I moved the DI to the spot in the picture it would be high enough to not block the SI.  Boat dealership did the DI install.  I plan on fixing that.

[jbrady2852]

If you could mount the DI transducer in the indented area of the transom, it would be forwards of the HDSi transducer and would not block any sonar.  They could still cause sonar-to-sonar interference though but your plan is to run one or the other so that won't be a problem.  You could even mount the DI transducer inside-the=hull if you wanted to as it looks to be a fiberglass hull. Then you could mount the HDSi transducer just to the side of the centerline of the boat (leaving enough room so it does not get hit by the motor).  You may have to trim the motor up when using the Si sonar so it does not block any Si sonar to that side.

BTW: you did not install the DI transducer hardware correctly; the two black plastic pieces should snap into each other.

What is involved in doing the inside-the=hull with the current DI transducer?  Any special poxy or suggestions.  Thinking since I am putting in the quadbeam I could just as easy move the DI to the same area.

[rnvinc]

What is involved in doing the inside-the=hull with the current DI transducer?  Any special poxy or suggestions.  Thinking since I am putting in the quadbeam I could just as easy move the DI to the same area.

It is always a good idea to test the area of installation as Doug explains here...

http://www.bbcboards.net/humminbird-sonar-gps/172972-installation-networking-information-resource.html

And use a slow cure epoxy...(24 hour cure)...

Rickie

[jbrady2852]

What is the power requirement for the 999ci.  Looking to configure and upgrade the unit before install.  I have a 13.8VDC 15A Power Supply that I use to power my 788ci DI unit.

[Humminbird_Greg]

15 amps is more than enough to power both units.
The 999ci HD Si should draw be less than 1 amp (the HB web site lists it as 780mA).