Airmar – Airmar 1 kW—TM258 Long Bracket User Manual

Page 4

AIRMAR

TECHNOLOGY CORPORATION

35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA

■

www.airmar.com

(3/8") deep. To prevent drilling too deeply, wrap masking tape
around the bit 10mm (3/8") from the point.

7. Allow about 10cm (4") of slack in the cable below the lower

cable clamp to accommodate the transducer in the “released”
position.

8. Apply marine sealant to the threads of the #6 x 1/2" self-tapping

screw to prevent water from seeping into the transom.If you have
drilled a hole through the transom, apply marine sealant to the
space around the cable where it passes through the transom.

9. Position the two cable clamps over the cable and fasten them in

place. If used, push the cable cover over the cable and screw it
in place.

10.Route the cable to the instrument

being careful

not to tear the

cable jacket when passing it through the bulkhead(s) and other
parts of the boat. To reduce electrical interference, separate the
transducer cable from other electrical wiring and the engine(s).
Coil any excess cable and secure it in place with zip-ties to
prevent damage.

11.Refer to your echosounder owner’s manual to connect the

transducer to the instrument.

Checking for Leaks

Warning

: When the boat is placed in the water,

immediately

check for leaks around the screws and any hole drilled in the hull.
Never install a transducer and leave the boat in the water
unchecked for several days.

Operation

“Up” position

Store the transducer in the “up” position when it is not in use (see
Figure 2). In the “up” position, the transducer is protected from
impact, but note that

the bracket will not release

. The “up”

position must be used when running at high speed [above 30kn
(35MPH)] to minimize drag. The “up” position will provide very
good fishfinding at boat speeds below 6kn (7MPH). Raise the
transducer to the “up” position by pulling on the latch line to
release the latch while pulling on the hoist line to raise the support
tube until the latch engages the lower latch pin (see Figure 4).

“Down” Position

Place the transducer in the “down” position for normal operation.
The bracket will release in this position. To lower the transducer,
pull on the latch line and lower the support tube (see Figure 4).

sure

that the latch re-engages with the upper latch pin.

“Released” Position

When the transducer is in the “down” position and hits an object in
the water, the bracket will release (see Figure 2). Also, when the
boat is making headway, the water exerts drag on the transducer.
As the boat speed increases, the force on the bracket increases
dramatically. Depending on the water conditions and the amount
the transducer projects below the transom, the transducer bracket
will release at about 40kn (46MPH).

After release, the transducer will ride atop the outwash from the
transom and cause minimal drag while the boat is making
headway. The transducer can survive in this condition if the water
is calm. However, pitching and rolling in rough water will stress the
bracket. Also, the transducer will sink at zero boat speed.

The

release feature is not intended to be a substitute for hoisting the
transducer

Caution

: Always reset the transducer in the “down” position as

soon as possible using a blunt pole.

Maintenance

Antifouling Paint

Aquatic growth can accumulate rapidly on the transducer’s
surface reducing performance within weeks. Surfaces exposed to
salt water

must

be coated with antifouling paint.Use

water-based

antifouling paint only.

Never

use ketone-based paint, since

ketones can attack many types of plastic possibly damaging the
transducer.

Apply paint to the transducer and all parts of the bracket up to
100mm (4")

above the waterline

. Repaint every 6 months or at the

beginning of each boating season.

Removing the Transducer

1. Lower the transducer into the “down” position.
2. Separate the transducer assembly from the mounting plate by

removing one safety ring and withdrawing the hinge pin (see
Figure 4).

3. Remove the bracket by grasping the support tube near the

mounting shoe and pulling away from the boat.

4. Replace the hinge pin and safety ring on the bracket.

Cleaning

Keep the support tube, guides, and rollers free of sand and grit by
washing them with mild household detergent.

Do not

use a

lubricant, since grit will stick to it increasing friction and wear.

If fouling is severe, use a Scotch-Brite

scour pad to remove the

growth,

being careful

to avoid making scratches on the

transducer’s face. Wet sanding the fouled surfaces with #220 or
finer grade wet/dry paper is permissible.

Storage

Avoid extremes of temperature. Low temperatures make plastic
brittle. Although the transducer is designed to withstand
temperatures up to 70

C (160

F), it is best to store the transducer

at a moderate temperature.

Parts

Lost, broken, or warn parts should be replaced immediately.

Bracket Assembly

33-432-01

Obtain parts from your instrument manufacturer or marine dealer.

Gemeco (USA)

Tel:

843.394.3565

Fax:

843.394.3736

email:

[email protected]

Airmar Europe

Tel:

+45.45.81.04.18

Fax:

+45.45.81.04.93

email:

[email protected]

Transducer Replacement

The information needed to order a replacement transducer is
printed on the cable tag.

Do not remove this tag. When ordering,

specify the part number, date, and frequency in kHz. For
convenient reference, record this information where indicated
near the top of page one.