531374-1_A - 947 Man.qxd 2/15/2005 7:53 PM Page 16

TRANSOM TRANSDUCER INSTALLATION

If you will be installing a transom mounted transducer, use the procedures in this section. There are several procedures you will have to perform in order to install a transom-mounted transducer. They are:

Determine transducer mounting location

Mount the bracket to the boat

Attach the pivot to the transducer

Mount the transducer pivot assembly to the bracket

Adjust the running position of the transducer

Route the transducer cable

Perform a final test of the transom transducer installation.

Stepped Hull

3

1

2

 

 

 

 

 

 

 

 

 

 

 

1 Rivets/Strakes

2 Deadrise Angle

Step 3

To determine transducer mounting location:

NOTE: If transom mounting is not possible because of a stepped hull or cavitation noise, and you have a single layer fiberglass hull, In-hull installation is an option. See Inside the Hull Transducer Installation for more information.

1.First, determine the best location on the transom to install the transducer. Consider the following to find the best location:

It is very important to locate the transducer in an area which is relatively free of turbulent water. As a boat moves through the water, turbulence is generated by the weight of the boat, and the thrust of the propeller(s) - either clockwise or counter-clockwise. This turbulent water is normally confined to areas immediately aft of ribs, strakes or rows of rivets on the bottom of the boat, and in the immed- iate area of the propeller(s). Clockwise propellers create more turbulence on the port side. On outboard or inboard/outboard boats, it is best to locate the transducer at least 15" (380 mm) to the side of the propeller(s).

The best way to locate turbulence-free water is to view the transom while the boat is moving. This method is recommended if maximum high-speed operation is a high priority. If this is not possible, select a location on the transom where the hull forward of this location is smooth, flat and free of protrusions or ribs.

The hydrodynamic shape of your transducer allows it to point straight down without deadrise adjustment.

On boats with stepped hulls, it may be possible to mount the transducer on the step. Do not mount the transducer on the transom behind a step to avoid popping the transducer out of the water at higher speeds; the transducer must remain in the water for the control head to maintain the sonar signal.

If the transom is behind the propeller(s), it may be impossible to find an area clear from turbulence, and a different mounting technique or transducer type should be considered (see Inside the Hull Transducer Installation).

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Humminbird 947C manual Transom Transducer Installation, To determine transducer mounting location, Stepped Hull