# Transducer placement



## bryan28 (Feb 27, 2012)

I have a G3 boat I want to add a fishfinder to. Problem is with mounting the transducer. I understand where/how it should be mounted but there is a welded "lip" where it should be. It's about the only spot far enough from the prop and in between ribs to avoid turbulance. Will mounting directly to this lip or above or to the right of it be alright? I'm wondering if it'll cause turbulance and cause the ducer to not operate properly. 

Thanks...Bryan


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## richg99 (Feb 27, 2012)

If it were I, I'd add a thick piece ( or two ) of plastic cutting board (Walmart) between the t'ducer and the hull.... and use longer screws. 

That should bump it out. The cutting boards will not deteriorate in water. R


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## RivRunR (Feb 27, 2012)

richg99 said:


> If it were I, I'd add a thick piece ( or two ) of plastic cutting board (Walmart) between the t'ducer and the hull.... and use longer screws.
> 
> That should bump it out. The cutting boards will not deteriorate in water. R



x 2
and if you should need to relocate it after trying it on the water, you don't have to drill more holes in the boat, only in the board.


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## fool4fish1226 (Feb 27, 2012)

RivRunR said:


> richg99 said:
> 
> 
> > If it were I, I'd add a thick piece ( or two ) of plastic cutting board (Walmart) between the t'ducer and the hull.... and use longer screws.
> ...




x 3


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## FuzzyGrub (Feb 27, 2012)

That looks to be a fixed tab, meant to help raise the transom and lower the bow, while underway. The water stream will be following the curvature of that tab. It may be problematic to mount the transducer there. Show a pic of your whole transom. There might be a better option.


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## muskiemike12 (Feb 27, 2012)

I would contact the manufacturer and find out where they suggest to mount a x-ducer on that model. Maybe you can mount it thru-hull. I believe Humminbird will swap out x-ducers if you want to go with a thru-hull.


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## bryan28 (Feb 27, 2012)

Here are some more pics for you. The inner edge of the lip is 16" from the prop when the wheel is straight.


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## FuzzyGrub (Feb 27, 2012)

It looks like you have a rib at the water inlet and one just to the left of the fixed tab. I would place a transducer mounting pad (like the guys described above) across there. Start at a mid-point position between ribs, for the 1st test. If this is a HB transducer, they tend to be larger and more finicky for placement.


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## Jdholmes (Feb 27, 2012)

I think your motor is sexy...just sayin.


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## bryan28 (Feb 27, 2012)

Thanks for the replies. I'm gonna get a mounting board and give it a shot. A G3 rep replied in an email that it's a trim tab and shouldn't cause any problems. Thanks JD. I'm kinda fond of it myself.


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## FuzzyGrub (Feb 27, 2012)

bryan28 said:


> Thanks for the replies. I'm gonna get a mounting board and give it a shot. A G3 rep replied in an email that it's a trim tab and shouldn't cause any problems.



If you are going forward with mounting over the tab, I'd get a second opinion from your FF tech support. I doubt they would agree. Good luck, and post back your results.


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## RiverBottomOutdoors (Feb 27, 2012)

Mounting over the trim tabs will definitely effect the speed at which your FF will read. 

I just installed a 798Ci SI and have been battling transducer placement. First position read at 27mph but made a 7ft rooster tail. I raised it and changed the angle and reduced the rooster tail and speed at which it will read by half.


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## jojo (Feb 27, 2012)

I would place it where the red circle is.


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## KevinWI (Feb 27, 2012)

jojo said:


> I would place it where the red circle is.



I believe the recommendation is to mount at least 15" from the outboard motor. That may be too close. Also need to see if the area under the boat is clear of rivets or other turbulent causing items.


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## FuzzyGrub (Feb 27, 2012)

KevinWI said:


> jojo said:
> 
> 
> > I would place it where the red circle is.
> ...



That 15" rule is broken all the time. It just can't be too close to the front of the engine such that the turbulance causes air to cavitate or air into cooling pick-up. It is common to mount SI transducers in close to the engine (to scan on both sides) but above the bottom of the boat. When the boat is on plane, the transducer is out of the water, and doesn't cause the problem I mentioned. In this case, the red circle is about 12" from the boat centerline, anyway. 

That spot is from I can see the best option and what I was trying to describe earlier. Given the welded fixed tabs, doubt this is a riveted jon. Even so, rivets are going to be a lessor evil than the tab or ribs.


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## bryan28 (Feb 27, 2012)

Thanks for the replies. I'm getting a mounting plate and will mount it between the ribs and play with transducer locations til I get it right. The red circled spot is about where i was gonna try first. Thanks again and I'll let you know how it turns out in a couple of weeks.


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## jojo (Mar 1, 2012)

Since I will be doing the same thing soon. I will ask the same question.

Where should I mount the transducer? Location 1 or 2?


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## FuzzyGrub (Mar 1, 2012)

Doesn't look like you have a tab, so either should be fine for 2D sonar. I like location 1 better if a SI transducer.


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## jojo (Mar 1, 2012)

I was thinking location 1 as well. Is there any advantage/disadvantage to either location?


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## FuzzyGrub (Mar 2, 2012)

jojo said:


> I was thinking location 1 as well. Is there any advantage/disadvantage to either location?



#1, being slightly deeper and closer to the centerline would have slightly better left side si than #2.

You can always put a mounting plate across both areas and you could test and see if there were any differences. I don't think so, but the proff is in the testing.


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## Nickvan (Mar 9, 2012)

I'm at the 7 ft rooster tail stage with mine... I epoxied mine on because I'm not going to drill holes below the waterline for anything nearly as esoteric as a first position on a finder. I really like the cutting board idea, though. I put some water in the boat last time out and tried to get a reading through the aluminum. Depth was about right (checked with paddle), but no contour. I don't know if I should go up or down next. Will post.


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