Transducer range

[CheapPelican]

Today I had a Spottie follow my lure to the surface. It lost interest. I noticed that the fish didn't register on my FF, even though it came up under where I guessed it would be within range of my transducer.

Generally, at what angle does the transducer do its thing? Does it shoot forward some or straight down?

[CheapPelican]

If it matters, my ff is a humminbird 570 Di

[lowprofile]

Usually straight down. Lately I've actually been watching chum drop under my yak and can see the marks of bigger fish in it but that directly under the transducer in the rear. Anything up front is lost. Im going to move it to the front portion though .

[GregAndrew]

Were you looking for it on Sonar, Down Imaging or both? If sonar only, were you using 200 or 455khz screen? Down Imaging shoots a fan shaped signal. If the transducer is mounted correctly, the signal shape would look like a fan opened vertically downward spread from side to side. You will only see stuff that is directly under or directly to the side and under the transducer. A fish just in front or behind the transducer will not show up on the DI screen.

The 200khz setting produces a cone angle of 25 degrees. At a hypothetical 90 degree cone angle, you would see an equal distance away from the line your transducer points as you see down. At 25 degrees, you will see less than 25% away from the that line. In other words, at 10 feet away from your transducer you will see stuff in a circle of less than 5 feet in diameter. The 455 setting produces a cone angle of 16 degrees which would be even less of a viewing cone.

At least a couple things can effect your actual cone angle. Sonar is based on sound waves that are much more spread than say a laser. So they go out and come back in wider than the stated cone angle. Also, rocking of your yak will make it so your transducer is not pointed directly down all the time. That will allow you to see things not in the cone directly below the transducer.

Hope this helps.

[CheapPelican]

I was definitely in the sonar screen. What khz I don't know. Gonna have to read the manual. It doesn't sound like she would have been inside either "cone".

The first time I read this I felt like "Ugh, words...words...numbers...words..." Second time it felt like I was in the Matrix and being uploaded with information. I don't think anybody could have explained it any clearer.

Thanks :you_rock:

[jorluivil]

If you catch a 100lb+ BSB it'll show on your screen:D