Mounting & Adjusting the Bracket

12° transom angle	13° angle	9° transom angle	21° transom angle
			three shims
			taper up
		one shim
		taper down
parallel	slight angle	parallel	parallel
May improve operation	May improve operation	May improve operation	May improve operation
above 20kn (23MPH)	above 20kn (23MPH)	above 20kn (23MPH)	above 20kn (23MPH)
one shim	one shim		two shims
one shim	one shim	two shims	taper up
taper down	taper down	taper down
slight angle	more angle	slight angle	slight angle

Figure 5. Adjusting the transducer angle

CAUTION: Do not position the transducer deeper in the water than necessary to avoid increasing drag, spray, and water noise and reducing boat speed.

CAUTION: The stainless steel bracket must be isolated from a metal hull to prevent electrolytic corrosion. If no shim is being used, place non-metal insulating washers between the bracket and the metal hull.

1.Apply marine sealant to the threads of four of the hex-washer- head screws to prevent water seepage into the transom. Being sure any shim(s) is in place, screw the bracket to the hull using a socket wrench (see Figure 4). Do not tighten the screws completely at this time.

2.Reinstall the transducer. While holding the transducer assembly against the bracket, insert the hinge pin through the upper hole in the bracket and the support. Slide the spacer onto the pin and push it through the remaining hole in the support and the bracket. Reattach the safety ring.

3.Slide a washer onto the locking pin. Push it through the lower hole in the bracket, slide it along the channel in the support, and through the second hole in the bracket. Slide the second washer onto the free end of the pin and reattach the safety ring.

4.With the transducer in the operational position, Use a straight edge to sight the underside of the transducer relative to the underside of the hull (see Figure 5). The trailing edge of the transducer should be 1–6mm (1/16 –1/4") below the leading edge.

5.Using the vertical adjustment space in the bracket slots, slide the assembly up or down until the bottom inside corner of the transducer projections 0–3mm (0–1/8") below the bottom of the hull (see Figure 1). When you are satisfied with the position of the transducer, tighten the four bracket screws. For clear access to the screws, remove the transducer assembly from the bracket (see Figure 4). When reattaching, be sure to include the spacer.

Testing on the Water

1. Test the transducer at 200kHz with the engine off.

2. Become familiar with your echosounder’s performance at a

speed of 4kn (5 MPH).

3. Gradually increase the boat speed and observe the gradual

decline of performance due to turbulent water flowing over the

transducer’s active surface.

NOTE: As the speed increases the performance at 50kHz will

deteriorate more rapidly because more acoustic noise is

generated at low frequencies.

4. If the decline in performance is sudden (not gradual), identify

the boat speed at which the onset occurred. Return the boat to

this speed, then gradually increase speed while making

moderate turns in both directions.

5. If the performance improves while turning to the side on which the

transducer is installed, it’s position probably needs adjustment.

The transducer is probably in turbulent or aerated water.

To improve performance, try the following, one at a time, in the

order given.

A. Increase the transducer’s angle in the water. Review “Shims”

and see Figure 5.

hole (2) mate with bosses on shim

screw (4)

stabilizing screw

NOTE: Draw an “X” at 21mm (1/2") from the top and bottom of both slots.

B. Move the transducer deeper into the water in increments of

3mm (1/8") (see Figure 1).

C. Move the transducer closer to the centerline of the boat.

Fill unused screw holes with marine sealant.

Stabilizing the Bracket

1. Prevent the bracket from moving out of position with the

remaining hex-washer-head screw. Drill the hole for the

Figure 6. Screw locations on bracket

stabilizing screw through the center hole of the bracket, any

shim(s), and the hull (see Figure 6).

13° angle

9° transom angle

May improve operation

above 20kn (23MPH)

Figure 5. Adjusting the transducer angle