Humminbird 1158c Combo Installation And Operation Manual page 44

3. Assembling the Transducer and Initial Mounting
In this procedure, you will assemble the transducer using the hardware provided, then mount it
and make adjustments to its position without locking it in place.
NOTE: You will initially assemble the transducer and the pivot arm by matching the two ratchets to a
numbered position on the transducer knuckle. Further adjustments may be necessary.
1a. If you already know your transom angle, refer to the chart below for the initial position
to use to set the ratchets. If your transom is angled at 14 degrees (a common transom
angle for many boats) use position 1 for the ratchets. In either case, go to step 2. If you
do not know your transom angle, go to step 1b.
Bead Alignment
Number
Transom Angle (°)
-2 -1 0
Measured Distance (x)
1b. If you do not know your transom angle, measure it using a plumb line (weighted nylon
string or monofilament line) exactly 12 inches long. Hold the top of the plumb line
against the top of the transom with your finger, and wait until the line hangs straight
down. Using a ruler, measure the distance from the bottom of the plumb line to the
back of the transom, then use the chart.
Measuring the Transom Angle
Plumb
line
12"
Transom
Angle in
degrees
(°)
Measured
Distance (X)
Transom Mount - DualBeam™ PLUS
1 4 2
1 2 3 4 5 6
0.0 cm 1.1cm 2.5 cm
0" 1/2" 1"
NOTE: It is important to take your measurement in the figure showing
Measuring the Transom Angle, from exactly 12 inches down from the
top of the transom.
2. Place the two ratchets, one on either side of the transducer
knuckle, so that the beads on each ratchet line up with the
desired position number on the knuckle. If you are setting the
ratchets at position 1, the beads on each ratchet will line up
with the rib on the transducer knuckle to form one continuous
line on the assembly.
NOTE: The ratchets are keyed; make sure that the square teeth on each
Weight
ratchet face the square teeth on the transducer knuckle, and the triangular
teeth face outward.
or...
5 3 1
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
4.3 cm 5.9 cm 7.6 cm
1 5/8" 2 3/8" 3"
32
4 2 5
9.3cm 11.1cm 12.9cm
3 5/8" 4 3/8" 5"
3 1
25 26 27 28 29 30
14.9cm 16.9cm
5 7/8" 6 5/8"