side image sonar

I am curious in how the side image transducer work's for a humminbird transducer. I have heard that the sonar will shoot down to the bottom before it shoots out to the sides. I have always been under the assumption that it just shoots straight out to the sides. The reason i ask this is because i am contemplating installing smart tabs on my boat and due to the boats design there is a a chance they will interfere with the side image display because they will hang just below the transducer . ...any thoughts would be much appreciated.

The SI piezos are situated in the SI housing at 30° from horizontal ...

http://i477.photobucket.com/albums/r...ps4069bebe.png

The sound pulse is strongest at this 30° from horizontal "Main Axis" ... (See beam form below) ...

The sound pulse diminishes continuously ...both "laterally away from the piezo" and "outwardly away from the Main Axis" ...until the sound pulse reaches -0db "Absolute Silence" ...

The beam angle specs dictated in sonar documentation is a "Measurement" at a specific db loss during the outward travel of this "continuously diminishing" sound pulse ...

http://i477.photobucket.com/albums/r...pskwnh5zhd.png

The beam form definately reaches from the water's surface to past vertical under the boat ...but the strongest echoes will be from reflective objects along this 30° "Main Axis" ...

Rickie

Ricky thank you for the quick response. Can you explain this more in simple form.

The SI beam will be obstructed by anything you put to the side of it.

The beam angle is virtually 90 degrees to each side and very narrow front to back.

If you don't have a place where you can mount a single transducer to get a clear view of each side, there is a wiring configuration where you can mount 2 SI transducers .....one for each side that electrically is seen as just one transducer by the unit.....This configuration will give excellent images, but you will have the expense of an extra transducer and the y cable to connect them together.

In simple terms ... Your Smart tabs will most likely show up in the SI image ...

Here is a pic with an obstruction to the right of the SI xducer ...notice the constant line running close to and parallel to the centerline ...

Your Smart tabs would have a line similar to this but on both sides of the SI centerline ...

http://i477.photobucket.com/albums/r...psl1xah2h9.jpg

If the tabs are low enough ... They could actually block some of the sound pulse from reaching targets farther away from the xducer ...

Rickie

Bob's mention of a 2nd SI xducer and the AS SILR Y cable is a very viable option for transoms that have obstruction challenges ...

Rickie

Guys thank u for your quick responses. I really appreciate it! In the picture with the line that runs parallel with the center line, i still see objects out to the sides. Do you think that the transducer can still pick up structure out 5 feet and out from the boat? I normally run it in 455 hz at 65 feet or so

It depends on how much the signal is blocked ..... that one is fairly mild blockage.

I would suggest mounting your Smart tabs and test ...

If there is blockage ... It may not even be bad enough to worry about ...

I definately would not be worrying about the minor blockage shown in the SI image I posted above (it's unlikely there will be fish that close to the xducer anyway) ...

Rickie

I am really only worried abo5 finding structure with my side imaging. I just dont want to waste the money on them and loose my imaging. Thanks again rickie

Here the main engine is slightly blocking the left side. The image on the right side is correct. Notice how the left side image is bouncing off the motor and showing a mirror image of right side. Bank with retaining wall is on right. Open water to the left

http://i453.photobucket.com/albums/q...pstzxitoy4.png