Specifications

A partial list of terms used is presented herein.

BEAM ANGLE: A transducer beam angle is shaped in an inverted cone (narrow at the top and

larger at the bottom). Most of the energy from the instrument is reflected back

to the transducer when it hits bottom. There are different beam angles for

different purposes. Generally, narrow beam angles are used on digital depth

sounders, medium beam angles for deeper depth, and wide angles for

applications where there is a need to look at a larger area below the boat.

GAIN Gain is another name for sensitivity control. The deeper the water, the more

(SENSITIVITY): gain you will require.

RANGE: The total depth capability, depending on bottom conditions. Maximum depth

tends to decrease as the bottom becomes softer.

THROUGH Plastic through hull depth transducers should be mounted in fiberglass and

HULL metal hulls only. Plastic should never be used in wooden hulls as the swelling

FITTINGS: of wood may overstress the plastic housing. Do not use bronze housings in

aluminum hulls since electrolytic corrosion will occur.

TRANSDUCER: All depth sounders emit ultrasonic sound signals that travel through water

looking for a strong return echo (impulse). Inside the transducer is a crystal

element that transmits as well as receives these pulses. The unit calculates the

amount of time for the signal to travel to the bottom and return back to the

transducer. It then converts this time into depth and displays it on the screen.

TRANSDUCER The rate at which the sonar vibrates. It is critical to installation that the

FREQUENCY: frequencyof the transducer and the frequency of the instrument be the same.

Sonar instruments are designed to operate on a frequency which can provide

different results such as shallow or deep water performance, etc. It is best not

to have two of the same frequency transducers on the same vessel, unless you

plan in advance for this type of installation with a Switch Box so that you can

switch from one transducer to the other.

GLOSSARY

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