Topic: dual transducer placement

[ddono]

I have a side imaging transducer installed on the stern of my aluminium hull boat,hooked up to my 998.Unfortunately i cannot maintain depth readings at speed despite shifting transducer up/down and adjusting tilt. I have purchased a XNT 9 20 with Y cable to sort it out,I hope. Was hoping for some advice before i start, especially before having to drill any holes.
I assume the SI transducer should be more to the centreline than the XNT, and a bit lower.
Can I mount them next to each other on the plastic block, SI inside and XNT on outside-they would be close to touching but with small gap.Should I place the SI more inboard over inner channel between strakes?
Should i put the XNT on the port side and keep the SI where it is on the starboard side.
Many thanks

[Humminbird_Greg]

Welcome to the Humminbird Side Imaging Forums ddono.

First off: how does the Si sonar work with the HDSi transducer installed where it is now?
Without seeing how your boat runs through the water I can only assume that placing the XNT-9-20 transducer closer to the center and lower on the hull will give better high-speed water depth readings.  From the looks of it that may mean installing it on the port side of the motor as your transom is populated with overflow and water intake ports on the right side.

Mounting the transducer right next to each other (both on the block or both not on the block) will result in the XNT-9-20 transducer blocking part of the Si sonar to that side of the HDSi transducer.  There are ways around this that include installing a second HDSi transducer and another, different, Y cable.  I would explore other less expensive mounting options first.

So just how thick is that plastic transducer mounting block?

[ddono]

Thanks Greg,
the block in total measures 2inches or around 50mm(plastic and aluminium-see photo).I did this to see if I could get transducer into clearer water and to allow me to adjust transducer without drilling more holes. The side imaging seems to work fine to right but not so well to left, the image fades off ver quickly to "dark".It could be that i need to tilt the motor out a bit and perhaps the block worsens this by extending it to far back-be interested in your thoughts on this.
Have included photo of port side too. Although there are outlets present on  starboard side I think I have room to install it on this side just to right of the dual outlets-would this interfere with the SI? or will it be "safer" to put it on starboard side.Thanks again,support is fantastic.
david

[Humminbird_Greg]

Yeah, I’m was thinking that those mounting blocks for the transducer pushed it back where you would have to tilt up the motor farther but you did not mention left Si sonar issues.  The good news is that typically the farther aft of the transom you can get the transducer, the better your chances of getting good high-speed 2D sonar readings as it gets the transducer out of the turbulent water flowing off of the transom.

The farther apart you can keep the two transducers, the less Si sonar the second transducer will block.  Think of it this way: close your left eye and hold your thumb up right in front of your right eye.  Your thumb blocks most of your line of sight just like a transducer mounted close to your Si transducer would.  Extend your hand out to arm’s length and you find that your thumb is only blocking a small portion of your line of sight, just as the second transducer would if mounted farther away from the Si transducer.