Moved transducer....now incorrect

[DYLBOSS]

This past week I decided to move my transducer (external transom mount) to accomodate my new trim tabs that will be arriving soon. Moved it about 4 inches inboard, 6 inches from outdrive. 1/8 to 1/4 inch below the hull.

Took out the boat today, and the depth finder is now showing that I'm in 30+ feet of water, when I'm really in 4ft of water. Has anyone ever seen this? I have a hummingbird fishfinder/depthfinder and cannot see any options of calibrating this in the digital menu structure.

 

[foodfisher]

Re: Moved transducer....now incorrect

I believe the instructions say 18" from prop. You appear to be so close that the prop wash has a negative effect.

 

[DYLBOSS]

Re: Moved transducer....now incorrect

But this is happening even when the engine is turned off, and I'm just running power to the depthfinder.

 

[RL Gman]

Re: Moved transducer....now incorrect

Is it angled properly? If it isnt tight and allowed to move with the water or angled improperly it will give inaccurate depths.

 

[DYLBOSS]

Re: Moved transducer....now incorrect

Is it angled properly? If it isnt tight and allowed to move with the water or angled improperly it will give inaccurate depths.

What angle should it be at? I have it mounted flat against the transom at 90 degrees, just like it was before. Just moved over about 4-5 inches.

 

[RL Gman]

Re: Moved transducer....now incorrect

Honestly, it was a fat chance that the angle was the problem...I mean, that would affect it, but I would find it odd that you would change the angle of the sonar...

As long as the transducer is pointing straight down, (no angle fore and aft or port to starboard) then it should be giving accurate depths.

I've had the hummingbird df's as well, and they used to give me some problems. Once I actually got in the water, removed it from the bracket, and held the angle myself...I actually found it was "pointing" the wrong way, and when I mounted it back, it was find after I found the proper direction. But that was an old model and other issues could have been at play.

One other thought I had was: If it is the fish finder type, they have a side sonar that is suppose to look for fish on the side of the boat, and they can extend 30+ feet. Check the options to ensure it is set on the depth sonar and not the side "fishfinding" sonar.

I know I'm grasping here...I'm just trying to help and racking my brain from back in my days of using a similiar DFer...sorry.

 

[DYLBOSS]

Re: Moved transducer....now incorrect

I appreciate you helping me brainstorm this. I'll check the settings on that. That could very well be the case. When I looked in the menu options, there didn't seem to be many. Although, in comparison to last year, it is telling me the depth of each fish that passes by right over top of the fish, and then in the bottom right corner is a different number, which used to be my depth.

 

[JimS123]

Re: Moved transducer....now incorrect

Transducers do have a limited life span. I usually go thru 2 of them before the unit goes bad. Maybe in the process of removing and rebolting it got damaged.

 

[DYLBOSS]

Re: Moved transducer....now incorrect

Transducers do have a limited life span. I usually go thru 2 of them before the unit goes bad. Maybe in the process of removing and rebolting it got damaged.

I was wondering that myself. I hope that's not the case.

 

[Capt'n Chris]

Re: Moved transducer....now incorrect

This past week I decided to move my transducer (external transom mount) to accomodate my new trim tabs that will be arriving soon. Moved it about 4 inches inboard, 6 inches from outdrive. 1/8 to 1/4 inch below the hull.

Took out the boat today, and the depth finder is now showing that I'm in 30+ feet of water, when I'm really in 4ft of water. Has anyone ever seen this? I have a hummingbird fishfinder/depthfinder and cannot see any options of calibrating this in the digital menu structure.

The theory that your transducer should be 15" to 18" port of starboard of the prop came about many years ago when boaters first began mounting them on inboards. There is no prop interference from an I/O or outboard unless you are idling, slow trolling or moving in reverse "boiling" water into the transom. At any other time, water is diverted aft and away from the boat.

 

[JimS123]

Re: Moved transducer....now incorrect

There is an electronics store in my neighborhood that will test a transducer for free, then sell you a replacment if needed. They service most brands. Maybe you could locate someone in your area.

 

[DYLBOSS]

Re: Moved transducer....now incorrect

There is an electronics store in my neighborhood that will test a transducer for free, then sell you a replacment if needed. They service most brands. Maybe you could locate someone in your area.

Hmmmm....Good thought. Thanks.