Garmin 340c Manual

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Fishnder 340C Owner’s Manual 3

InstAllIng the fIshfInder 340c > MountIng the trAnsducer

Shoot-Thru-Hull Installation

To avoid drilling a hole to mount a thru-hull transducer, a

transducer can be secured with epoxy inside a boat (shoot-thru-

hull installation). This type of installation can provide better

noise reduction and allow you to use a higher Gain setting. For

a transducer to be mounted inside the hull (shoot-thru, not thru-

hull), the boat must be berglass, with no core. Contact your boat

manufacturer if you are unsure. Professional installation might be

necessary. Be sure to always wear a dust mask and safety goggles.

Some transducers are specically designed to be mounted inside a

berglass hull. The standard plastic transom mount transducer can

also be mounted using this method. If using a temperature sensing

transducer, the temperature shown reects the hull temperature.

Selecting a Location for a Shoot-Thru-Hull Installation

When installing a transducer, the installation location must be the

following:

• Solid berglass, without any air bubbles, laminates, llers, or

dead air space.

• In an area of clean (non-turbulent) water at all speeds.

• The location must not be over any strakes or behind any

obstruction on the hull that would create turbulence at speed.

Many modern hulls have a dedicated pocket for

shoot-thru-hull transducer installation. If you are unsure if your

hull is equipped with a pre-located pocket, contact your hull

manufacturer.

To test the location:

1. FabricateatestdevicefromasectionofPVCpipeoracan,

as shown in the following illustration.

2. Temporarilysealthetestdevicetothehullwithcaulkingor

RTVsealer,andllwithwaterorlightmineraloil.

3. Placethetransducerinthewater,pointeddirectlyat

thebottomandweightitdown.Settheunitforoptimum

performance.Ifthesonarperformanceissignicantly

degraded,anotherlocationmustbetested.

Testing the Location

Strip caulk

or RTV sealer

Hull surface

PVC pipe

or a can

Weight the transducer to

hold it in place.

Fill a pipe or can with water

or a light mineral oil.