Humminbird 1158c Combo Installation And Operation Manual page 37

5. Adjusting the Running Position of the Transducer
The transducer mounting bracket allows height and tilt adjustment, while the pivot bolt allows
angular adjustment. These adjustments will help reduce cavitation. Initially, adjust the transducer
as described in the following paragraphs. Further adjustment may be necessary to refine the
installation after high-speed testing.
1. First, adjust the pivot angle of the transducer body, so it is parallel with the length of
the hull of the boat.
2. Fully tighten the two pivot screws, using the supplied Allen wrench. Access to the pivot
screws is provided by the lower holes in the side of the mounting bracket. It may be
necessary to re-tighten the pivot bolt after initial use as the plastic may still be
conforming to the pressure from the lock washers.
Tighten the Mounting Screws
5. If access to the top mounting hole is not possible due to the selected height of the
transducer, fully tighten the two lower screws, then simply remove the headed pivot pin
and the transducer assembly, and tighten the top screw, then reassemble.
6. Confirm that the pivot angle has not changed and that all mounting screws are fully
tightened.
6. Routing the Transom Transducer Cable
The transducer cable has a low profile connector that must be routed to the point where the
control head is mounted. There are several ways to route the transducer cable to the area where
the control head will be installed. The most common procedure routes the cable through the
transom into the boat.
NOTE: Your boat may have a pre-existing wiring channel or conduit that you can use for the transducer
cable.
Normal Cavitation
3. Adjust the height of the assembly so the face of the transducer
is 1/8" (3 mm) to 1/4" (6 mm) beneath the bottom of the
transom, and fully tighten the three mounting screws.
4. In order to gain access to the mounting screws, the transducer
assembly must be pivoted up in the bracket as shown. Be
careful not to alter the running angle as some force is
necessary to pivot the assembly.
Cavitation that will cause
erratic sonar readings
25
Transom Mount - Side Imaging®