Humminbird XTH 9 DB 74 P Manual

Plastic Thru-Hull Transducer
Thank You
Thank you for choosing Humminbird®, the #1 name in fishfinders. Humminbird® has built its reputation by designing
and manufacturing top-quality, thoroughly reliable marine equipment. Genuine Humminbird® accessories offer the
opportunity to upgrade and expand the capabilities of your Humminbird® product.
Your Humminbird® is designed for trouble-free use in even the harshest marine environment. In the unlikely event that
your Humminbird® does require repairs, we offer an exclusive Service Policy - free of charge during the first year after
purchase, and available at a reasonable rate after the one-year period. For complete details, see the Warranty section
included in this manual.
Installation Overview
Following are instructions for the installation of this accessory. Before you start installation, we encourage you to
read these instructions carefully in order to get the full benefit from your Humminbird® accessory.
NOTE: This type of transducer installation is not recommended for trailerable boats.
NOTE: This transducer requires drilling a hole in the hull of the boat; therefore, installation should be performed by a
qualified marine technician.
Supplies: In addition to the hardware supplied with your transducer, you will need a drill, a small drill bit for a pilot
hole, a 1 1/8" hole saw, a level, marine-grade silicone sealant, and dielectric grease.
Installation
Perform the procedures in the following sections to install the transducer on your boat.
1.
Testing the Transducer Prior to Installation
Prior to installation, test the transducer to make sure that no damage occurred during shipping.
1. After connecting the transducer to the control head, hold the transducer in the water over the side of the boat
to confirm proper operation. If the transducer is working properly, you should be able to see the bottom on the
control head display. The bottom image should be relatively strong and there should be detailed structure on the
display.
2.
Locating the Transducer Mounting Position
Outside the boat, the best location for the transducer will be aft midship, as close to the centerline of the boat as
possible. The transducer should be mounted forward of the propellers on inboard boats, and separated adequately
from other transducers, strakes, rivet lines, or other protrusions. Make sure that there is nothing in front, behind, or to
the side of the transducer that is closer than 12". Inside the boat, there must be room to access the mounting location
for installation and cable routing.
WARNING! Do NOT install the transducer in line with the engine intake.
Deadrise: Another consideration is the angle of deadrise. The transducer, when mounted, should point straight down.
If the selected mounting location has a hull deadrise of 8 degrees or greater, the included leveling block should be
used to level the transducer housing and direct the sonar signal straight down. If you need to use the leveling block,
make sure that the inside surface of the hull is smooth enough to seat the leveling block securely.
Thru-Hull Installation
Deadrise Angle
Areas of Possible Turbulence
Rivets Transom
Strakes Hull
Preferred Mounting Location