Topic: Transducer Angle

[Submaster]

I've read in another post that the way to verify the transducer is level is to drive by a known object such as a bridge pilling.  Well I've done that and the bridge pilling is suppose to be straight out, but mine is at a slight angle.  The picture below shows the bridge pilling is slanted downward.  My question is: 1. I'm I just being to anal!? or do I need to adjust my transducer?  2. If I really need to adjust my transducer, which direction do I need to go based on the picture.  Thank You.

[Humminbird_Greg]

Sometimes there is some give and take with the tilt angle on a transducer: tilted down it may read the 2D sonar at a higher boat speed and with it level with the water objects in the Si will appear straighter (not sure how to explain that) and fish arches will be more equal length front-to-rear.  So you may have to choose which you want.  If you are using a second 2D transducer; than adjust for the best Si sonar readings and straighten that transducer out!  LOL!

If the top of the object is showing up first, than you need to lower the backend of the transducer downwards (or trim your boat nose up).

[Submaster]

What I need to add was I'm traveling from the bottom to the top of this picture.  I'm running only one transducer. So if I understand correctly, then in this scenario I need to bring the back end of the transducer up a hair.

[Humminbird_Greg]

No, I think that you need to drop it down a hair or two.
In a normal Si View the boat is travelling from the bottom to the top just like in the HummViewer image you posted.  So the parts that are lowest in the picture are what showed up first.  When the transducer is nose down/tail up, the upper part of each Si beam will hit the top part of the bridge pilings first and be shown first (lowest in the image).  To offset this you must bring the nose of the transducer up and the tail of the transducer down.

Someone else can check me on this as I have gotten this backwards before!

[LittleGazoo]

If the top of the object is showing up first, than you need to lower the backend of the transducer downwards (or trim your boat nose up).

Now I'm confused(but not difficult to do).

If I'm reading his recording correctly, then the top of his piling is showing up last.  So he needs to raise the backend of his transducer???

 I used a carpenter's level to determine my TR-186's plane when idling, then duplicated that plane when on the trailer, then leveled my transducer.

But I have a Triton TR-186(smaller boat) and boat load can effect my transducer's level position.  So I also use my motor trim when idling to compensate the transducer's level on-the-water plane.

But I've also heard that a bridge piling is supose to be a little tilted, as the top of the piling is closer than the bottom of the piling measured from the transducer.  If so, the which way should the piling be leaning?

[Submaster]

LittleGazoo,
   I did the same thing...I took my level out to the lake and recreated the same conditions back home on my trailer; however, I seem to a little off.  I'm taking Humminbird_Greg's advice and adjusting ever so slightly...if it's the wrong direction, I guess I'll just have to readjust the other direction.  My main concern is that I'm not being to anal in trying to chase this thing to ground. At some point it will be just good enough.  Thanks for all the help.

[Humminbird_Greg]

LG, he stated that in the image he posted that “I'm traveling from the bottom to the top of this picture”.  So that would put the top of the bridge piling showing up first as it is lower in the picture.  I don’t know about any tilt to bridge pilings.  But if they were why would they tilt in that direction as it would be cross-wise to the direction of the road?  Seems like they would be tilted in the direction of the road either way if they were tilted at all.


Submaster, I think that if you can see that there is a tilt than you should adjust it.

[LittleGazoo]

LG, he stated that in the image he posted that “I'm traveling from the bottom to the top of this picture

I'm back on plane now!
Thanks Greg