Saturday, May 21, 2011

Sonar Fish Finder will not show fish on screen?

How the fish finder works:----

All fishfinders operate using Sonar uses sound waves to "view" underwater objects. A sound wave is produced by the fishfinder and sent through the water. At the source, the wave is narrow; however as it penetrates deeper, the sound wave spreads forming a cone, or what is commonly called a beam (think flashlight). When the sound wave encounters something within this beam, it bounces back to the fishfinder. By measuring the very small amount of time between when the sound wave was send out and when it bounces back your fishfinder calculates the distance and draws it on the screen.

If the signal doesn't encounter anything along the way, it reaches the bottom. Soft bottoms like mud and weeds tend to absorb the signal. Hard bottoms such as rock reflect a stronger signal back. These subtle differences in sonar reflections appear on the display screen. That's how a fishfinder "reads" the bottom and everything in between.------------


Eagle Cuda 300 Sonar Fish Finder will not show fish on screen:----------------

It can be the problem with transducer if you see no fish on display.----

What is transducer :---

The Transducer The transducer takes the electrical signal from your transmitter, turns it into sonar, and sends it out. It also captures all returning echoes and converts them back into electrical signals. Transducers are mounted in the water, either on the transom, the inside the hull, or on the trolling motor. All transducers should be mounted straight down and away as far from motors, props and hull obstructions as possible. A cable connects the transducer to the fishfinder.

To select the transducer that's best suited to your needs, you need to consider the transducer's operating frequency, cone angle and type of installation.

Frequency Most of the sonar units that we sell accessories for operate at 192 or 200 kHz (kilohertz). Some models use 50 kHz. A few are dual frequency capable, meaning they can use both 50 and 200 kHz transducers. Typically, high frequency (192 or 200 kHz) sonar units provide the best resolution and definition of structure and targets. They excel at showing minute details of the underwater world. 50 kHz units have much greater depth penetration capability, but show less definition. 50 kHz transducers also usually have a much wider cone angle than 192 or 200 kHz transducers.

You must match the transducer's frequency to the sonar unit. For example, a 192 kHz sonar unit requires a 192 kHz transducer.

Cone Angle A transducer's cone angle determines its coverage area of the underwater world. The wider the cone angle, the greater the area that's covered. We offer a variety of 192 kHz transducers with either a wide (20°) or narrow (8°) cone angle. We also offer a variety of 200 kHz transducers with either a wide (20°) or narrow (12°) cone angle. The 50 kHz transducers come with a 35° cone angle. And the dual frequency transducers come with both a narrow (12°) 200 kHz and a 50 kHz cone angles.

Generally, use a wide cone angle for fishing shallow to medium depths. The narrow cone penetrates to deeper depths, but shows less fish and structure due to its narrow beam.

The depth capability of your sonar units depends on its transmitter power, receiver, sensitivity, frequency, transducer and transducer installation. Other things that effect depth capability are: water conditions and type, (all sonars will show deeper depth readings in fresh water than salt) and bottom conditions.

Types of Transducer Installations Most of our permanent-mount transducers are designed for high-speed operations. For the best results, the transducer should be placed where a smooth, undisturbed flow of water will pass across the face of the transducer at all boat speeds. Read your transducer's owner's manual before installing the transducer!
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FishTrack™
The FishTrack™ feature shows the depth of a fish symbol when it appears on the display.
To turn on/off FishTrack:
1. Press MENU until the FISH ID menu appears. Press ↑ ↓ to select TRACK
or OFF.
2. Press PWR. (If you want to turn off FishTrack depths but leave Fish
I.D. on, press ↓ to select ON, then press PWR.) Remember, Fish I.D.
must be on in order to use the FishTrack feature.
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Fish I.D.™
The Fish I.D. feature displays fish symbols on the screen in place of the
actual fish echoes. There are three symbol sizes: small, medium and
large. These show the relative size between targets.
To see what's under your boat in maximum detail, we recommend you
turn off Fish I.D. and begin learning to interpret fish arches.
To turn Fish I.D. on/off:
1. Press MENU until the FISH ID menu appears. Press ↓ to select ON/OFF.
2. Press PWR to clear the menu from the display.
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Sensitivity
Sensitivity adjusts the way echoes will be displayed on the screen. If
you want to see more detail, try increase sensitivity. If your unit is
picking up a lot of clutter, decrease the sensitivity to reduce the
amount of clutter displayed on the screen.

To adjust sensitivity in Auto Mode:
1. Press MENU until the SENSITIVITY control bar appears. Press ↑ to increase
the sensitivity, ↓ to decrease it.
2. Press PWR to clear the menu. If you reach the maximum or minimum
sensitivity level, a tone will sound.
To turn on Manual mode:
1. Repeatedly press Menu to display the Sensitivity menu. Highlight
MANUAL and press PWR to clear the menu.


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