Humminbird Side Imaging Forums

General => General Discussion => Topic started by: Deadbait on April 06, 2017, 01:45:19 PM

Title: Mega si transducer position
Post by: Deadbait on April 06, 2017, 01:45:19 PM
Hi Guys,

In a few days I hope to recieve my new humminbird unit, a Helix 9 g2n Mega .

At the moment I am prepairing my boat to mount the unit and transducer but I am a little in doubt where to place te transducer (side imaging).

I would like to place it in at the location of the red rectangle in the attached picture.
That way the transducer will be free to "Watch" both sides without any obstructions.

But the manual says to stay 38centimeters (I'm from the Netherlands) from the prop. That way the green rectangle would become the best poition. But I am a little afraid that the cavitation plate from the motor will block the side image to portside. I can trim my motor a little bit more up but not to much as I want to use the side imaging also when driving slow speed on the outboard.

Does anyone now how important the 38cm are? I see a lot of pictures from side image transducers placed near the center of the boat.

I also read that the side image beam is very thin (like a laser thickness). Does this come from the middle of the transducer to the left and right, or from the back or front of the transducer?
If it's from the middle or front (and very narrow) it will probably miss the outboard parts, see picture 2 in the attachement.

Maybe someone here can give me some advise?

ps The transducer will be mounted on a transducer plate.

Best regards.
Title: Re: Mega si transducer position
Post by: rnvinc on April 06, 2017, 04:29:24 PM
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 ... 
-----

The SI beam emits from the entire side length of the xducer housing ... It is normal to have to trim the motor up when scanning for the SI beam to clear the lower unit ...

(http://i477.photobucket.com/albums/rr134/rnvinc/HB/null_zpse783befa.png) (http://s477.photobucket.com/user/rnvinc/media/HB/null_zpse783befa.png.html)

Rickie
Title: Re: Mega si transducer position
Post by: Deadbait on April 07, 2017, 06:47:08 AM
I thought that the minimun 15" would be for staying away from turbulence. But if it is only to stay away from the water intake I probably can place it somewhere near the red rectangle and have no obstructions in the view.

Thanks for the reply!
Title: Re: Mega si transducer position
Post by: Deadbait on April 14, 2017, 01:20:24 PM
Hi,

For the people with the same question about the location.

I recieved my Helix and installed the transducer. In the attachement some pictures.
I have had a little test run yesterday evening. It works fine, I just have to trim the outboard a little up to get a clear view to both sides. Also at high speed when in plane I get a good depth reading.
This is my first side image fishfinder and I really like the details it is showing. Even in the shallows you can see fish swimming a couple of feet next to the boat.

The only thing I noticed is that the depth reading is a little erratic when traveling over the shallows (3-4feet of water) it's reading the right depth at one moment but jumps to like 20 feet the other. I already read some things about this. So tommorrow I will check if I can get a proper steady and correct reading in the shallows by making some adjustments in the sonar settings.
Title: Re: Mega si transducer position
Post by: Tbonk81 on May 08, 2017, 10:32:00 AM
I also have the mega imaging and i have no issues with the depth jumping around in the shallows. I have last years helix 9 also and did not have issues with that. Just an FYI in case you were wondering if others have the same issue.
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