Transducer range - Kayak Fishing Adventures on Big Water’s Edge

GregAndrew · 05-27-2012, 04:12 PM

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.

05-27-2012, 04:12 PM	#4
GregAndrew Senior Member Join Date: Mar 2009 Posts: 2,384	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.