Airmar P48W - Manual (Page 5)

Figure 10. P48W transom mount: Adjusting the beam angle
Copyright © 2008 Airmar Technology Corp.
To adjust knob:
push, turn, and
release
NOTE: Knob
corresponds to
shape and direction
of beam.
cover
screw (2)
knob
beam angle
transducer
(6 x 1/2 ") (6 x 1/2 ")
(0° shown)
Locating & Installing the Fitting
CAUTION: Do not put tension to the cable where it exits the
transducer, since excessive force can break internal connections.
CAUTION: On bow mounted motors, be sure the cable route does
not result in pinching the cable when the motor is in the “up” position.
NOTE: P48W—It may be easier to adjust the beam angle before
the transducer is mounted on the trolling motor. See “Operating:
P48W” on page 5.
1. Purchase a stainless steel band clamp, available in the plumbing
section of most hardware stores. Be sure to measure the
circumference of the trolling motor to determine the correct size.
2. Loosen the screw in the band clamp so that one end of the
band is free. Pass the free end through the two slots in the
trolling fitting (see Figure 8).
3. Wrap the band clamp around the motor case with the sensor
located on the underside (see Figure 9). Tighten the screw on
the band clamp.
TM150M—Be sure the cable exits through the notch in the
trolling motor fitting, and there is no tension on the cable.
NOTE: If the motor has a strut that shades the transducer, it will
not significantly reduce the transducer’s performance.
4. Route the cable around the side of the motor case and along the
support tube. Secure the cable to the support tube with cable ties.
P48W—Allow sufficient cable so the user can change the beam
angle of the transducer.
5. Route the cable to the echosounder being careful not to tear the
cable jacket. To reduce electrical interference, separate the
transducer cable from other electrical wiring.
In-Hull Mount: P48W Only
NOTE: Do not in-hull mount the TM models as they will over-heat.
Although the performance will be diminished, the transducer can
be adhered directly to a solid fiberglass hull—NO coring.
Instructions are available at airmar.com. Go to Marine Products
>Installation Instructions>In-Hull Transducers and click on “P72,
P74, P76” (part number 17-010).
Operating: P48W
About Adjusting the Beam Angle
The transducer transmits an elliptically shaped beam that can be
adjusted to different angles: fore-aft (0
°) , port-starboard (90 °) , 23 °,
or 45 ° . The degree setting indicates the widest part of the beam.
Note that the width of the beam will be different at each setting.
To understand when to use each beam setting see the table below.
Adjusting: Transom Mount
To change the beam angle, grasp the transducer knob, push down,
rotate to the desired setting, and release the knob (see Figure 10).
Check that the transducer is locked into the setting by running your
hand along the bottom of the transducer to be sure it is flush with
the fitting.
NOTE: Knob corresponds to the direction and shape of the beam.
Adjusting: Trolling Motor or Portable Mount
The beam angles are marked on the underside of the trolling
motor fitting (see Figure 11). To change the beam angle, grasp
the transducer and pull outward. Rotate it until the orientation
mark is aligned with the desired setting and release the
transducer. Be sure the transducer is locked into the setting after
the knob is released.
NOTE: When an angle is set, the orientation mark will indicate the
direction of the widest part of the beam. It will also be aligned with
the elliptically shaped knob on the top.
Setting
Fore-Aft
Beam Width
Port-Starboard
Beam Width
Application
0 ° 38 ° 12 ° Best high-speed bottom detection
Fish appear as large arches
23 ° 36 ° 18 °
Good high-speed detection
Fish appear as prominent arches
Wider side-to-side beam than at 0
°
45 ° 29 ° 29 °
Detection similar to conventional
wide-beam transducer
Equal size beam width in both
directions
90 ° 12 ° 38 °
Maximum detection while boat is
moving forward
Good high-speed bottom detection
Fish arches are not pronounced or
may not be evident
5
Figure 11. P48W trolling motor mount: Adjusting beam angle
Copyright © 2008 - 2012 Airmar Technology Corp.
top view bottom view
knob corresponds
beam
orientation
mark
(90° shown)
to shape and
direction of beam
transducer
angle