Helix 7 G2 DI GPS transducer location help

Hi all. I have a Helix 7 G2 DI/GPS and was hoping to get some feedback with regards to getting a better image at high speeds. I've been in contact with Humminbird but have not heard from them in over a week. My boat has smart tabs on the outside of the transom. There is also a pitot installed so I was limited on where I could install the transducer. I originally had it installed closer in toward the motor (within the 15"). It was near a strake but I thought far enough away that it would not create a problem. It worked fine with the gas motor off and at trolling speed. However, the screen would eventually fill with red as I increased speed. I thought this was due to turbulence (prop wash or the strake) so I swapped the position of the pitot and the transducer.


The current position further away from the motor/prop but is still within 15". However, the transducer is now clear of any strakes and there is nothing in front of the transducer to create turbulence. With the current transducer location I can keep bottom reading up to about 20mph. The screen starts out normal but as I increase speed the screen seems to wash out or loose the image. This is the opposite of what I saw originally when the screen filled red. I used a split screen of 2d and DI. The 2D screen loses bottom completely and often shows depths that are not reflective of what I know they should be (e.g., in water of 30ft but it may read 75ft or higher). The DI screen seems to always keep bottom but is very fuzzy. I thought the transducer may not have been low enough so I lowered it a little but got the same results.

I have attached a few screenshots. The screenshot at 20mph is the best I can get at that speed. The 2D will completely wash out above that speed but the DI is still slightly readable. Since the DI is still picking up the bottom it seems the transducer is in the water. Is it possible the transducer is too low? Any suggestions based on the attached screenshots?

Any help would be appreciated.

Thanks,


Screenshot at 20mph (2D washes completely out above this speed):

Attachment 262989


Screenshot at trolling speed 5mph:
Attachment 262991

​Screenshot with gas motor off (drifting or using trolling motor):
Attachment 262990

1st - The 15" minimum in the installation is for outdrive boats ... Outboards need only be concerned with not mounting the xducer directly in front of the lower unit water intakes ... because the xducer can create turbulence (air) to enter the intakes ... And do not mount the xducer so close to the lower unit that the motor hits the xducer housing at full lock turn to that side ...

2nd - it's not unusual for the screen to fill with what looks like clutter as the boat speed increases... This is merely aerated water (bubbles) being created from the boat hull ... (Each area of the transom will have a different amount of aeration creation)...

While it is entirely possible to get better (cleaner) Imaging ... It is always tied to finding a spot on the transom with the least amount of turbulence being create by the boat hull ...

Sometimes this means moving the xducer up/down/over/ or even rearward ...

http://i477.photobucket.com/albums/r...ps11mocrex.jpg

Be patient and make minor adjustments until the "sweet spot" for your specific hull design is obtained...

And even realize - how much weight is in the boat at any given time will change how the hull contacts the water which may also cause different results between tests ...

Rickie

Thanks for the response. I was hoping the screen shots would lead to a quick fix but sounds like I'll have to keep making slight adjustments from here.

I've previously seen the diagram that you posted. It seems to indicate to raise the transducer and also raise the tail end of the transducer slightly. Most directions that I have seen online suggest lowering the tail end slightly. Just curious if you have tried the approach in the diagram? It almost seems the bottom of the transducer is higher than the bottom of the boat from the diagram.

Quote:

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Originally Posted by Allsop

Thanks for the response. I was hoping the screen shots would lead to a quick fix but sounds like I'll have to keep making slight adjustments from here.

I've previously seen the diagram that you posted. It seems to indicate to raise the transducer and also raise the tail end of the transducer slightly. Most directions that I have seen online suggest lowering the tail end slightly. Just curious if you have tried the approach in the diagram? It almost seems the bottom of the transducer is higher than the bottom of the boat from the diagram.

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Every boat is different because no 2 boats have the exact same hull design - with the exact same motor weight - with the exact same weight distribution of stuff in the boat ...

It's a matter of how much patience each individual has when trying to find that "sweet spot" of clean bubble free water ...
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Have someone drive the boat and peek over the transom (don't fall out) ...

Look for a spot where the water coming out from under the hull at speed is the same color as the water at rest ... White water coming from under the hull is aerated ...

Rickie