Humminbird 100SX Single Beam User manual

INSTALLATION PREPARATION
PARTS SUPPLIED
PARTS SUPPLIED
Before installing your new Humminbird fishfinder, please ensure the following
parts are included in the box:
•Fishfinder
•Transducer with 20’ (6m) of cable and mounting hardware kit
•Mounting system and mounting hardware kit
•6’ (2m) power cable
•Publications kit
It any of these items is missing, call our Customer Support Hotline.
ACCESSORIES
Humminbird offers a wide assortment of accessories that complement and
expand the capability of your new fishfinder. These accessories are designed
with the same high standards and are backed by the same one-year warranty.
The Humminbird Accessory catalog included with your unit contains descriptions
of the many accessories available and ordering information. All Humminbird
accessories are available through your full-service Humminbird dealer or factory
direct through our number listed in the Customer Support section.
INSTALLATION OVERVIEW
Your Humminbird fishfinder consists of two primary components to install: the
control head and the transducer.
The control head contains the sonar transmit and receive circuitry, as well as the
user controls and display. It should be installed in a location that provides access
to the controls and visibility while in use. The control head mounts on a quick
disconnect mounting system that swivels and tilts providing flexibility for viewing
from almost anywhere on the boat.
The transducer converts electrical energy from the transmitter into mechanical
pulses or sound waves. The transducer also receives the reflected sound waves
and converts them back into electrical signals for display on the control head. It
should be installed in contact with the surface of the water in an area that has
smooth waterflow-usually on the transom ofthe boat. There are several
mounting options for the transducer. Review the following section to determine
the method that works for you and your boat.

INSTALLATION PREPARATION INSTALLATION OVERVIEW
Determining How to Mount the Transducer
Your Humminbird fishfinder includes a standard
transducer. This transducer can be mounted on the
transom of the boat or bonded to the inside of a fiberglass
hull boat.
The transom installation, which is the most widely used,
places the transducer on the outside of the boat hull. This
technique produces the least signal loss, and provides a
way to adjust the transducer after installation. The
mounting hardware included is designed to protect both
the boat and the transducer should the boat strike debris in
the water or when trailering.
As an alternative to transom mounting, it is possible on
many fiberglass-hulled boats to glue the transducer on
the inside of the boat hull. Since fiberglass has similar
sonar characteristics as water, the sonar signal can
pass through the boat hull with minimal loss. The hull
of the boat must be single layer construction (not
double-hulled) Also, any air trapped in the lamination
of the fiberglass would prevent the sonar signal from
passing through.
Inside the hull installations require no holes be drilled
into the boat and through experimentation, high-speed
operation comparable to transom mounting can be achieved. Two-part slow cure
epoxy (not included) is required to glue the transducer in place.

INSTALLATION PREPARATION
ALTERNATE MOUNTING METHODS
ALTERNATE TRANSDUCERS AND MOUNTING METHODS
Your Humminbird fishfinder comes with everything necessary for installation and
operation on most boats. However, there are several situations which may
require a different type of transducer. Inboard boats, wood or metal hulls, and sail
boats create unique transducer mounting needs Alternate transducers and
mounting methods are detailed below.
Portable Mounting
The standard transducer can be adapted for portable
installations with a portable mounting kit available from
Humminbird. This accessory adapts your transducer to a
suction cup mount for temporary installation on the boat hull
or other surface.
Trolling Motor Mounting
The standard transducer can also be adapted to mount on
most trolling motors using a different accessory kit. This
accessory includes a bracket and hose clamp that allows
mounting the transducer to the body of most trolling motors.
Thru-Hull Mounting
Thru-hull transducers install through a hole drilled in the hull
of the boat. Larger boats or boats with inboard motors create
turbulence that make transom mounting ineffective. Also,
hulls that are very thick or are double layered, or made from
materials such as wood or metal, (which do not conduct
sonar signals) make inside the hull mounting inadvisable.
Thru-hull mounting may require the use of a fairing block to level the transducer
with the waterline. Also, since special tools and knowledge may be required to
perform this type of installation, it is best to refer to a qualified marine technician.

INSTALLATION PREPARATION
TRANSDUCER EXCHANGE
TRANSDUCER EXCHANGE
Other transducers are available as replacements for the standard transducer.
You may exchange your new and unassembled transducer for another type by
returning it to the address listed in Customer Support. Some transducers may
have additional cost. Refer to the Accessory catalog or call Customer Support for
information.
BEGINNING INSTALLATION
Now that you have determined the transducer mounting method you can begin
installation of your new Humminbird fishfinder. The installation guide included on
the next few pages provides detailed step by step instructions for installation of
the control head and transducer. For transom mount transducer installations you
will need the mounting template included with your manual.
In addition to the parts included you need the following for installation and
operation:
•A powered hand drill and various drill bits
•Philips and flat-head screwdrivers
•A ruler or measuring tape
•Pen or pencil
•12 volt power source (your boat’s battery)
•A 1-amp fuse
•A fuse holder (if you are wiring directly to the boat’s battery)
•Silicone sealant (for sealing drilled holes)
•2-part, slow-cure epoxy (for inside the hull transducer installations)

INSTALLATION
TRANSOM INSTALLATION
Do not begin this transducer installation until you read the Installation
Preparation in the Operation Guide. This chapter contains information
critical to the correct installation of your transducer.
Due to the wide variety of boat hulls, only general instructions are
presented in the installation guide. Each boat hull represents a unique set
of requirements that should be evaluated prior to installation.
TRANSOM INSTALLATION
Step One -Determine Where to Mount the Transducer
Begin the transducer installation by determining where on the
transom to install the transducer. Consider the following to find
the best location:
•It is very important to locate the transducer in an area which is
relatively free of turbulent water, As aboat moves through the
water, turbulence is generated by the weight of the boat, and
the thrust of the propeller(s). This turbulent water is normally
confined to areas immediately aft of ribs, strakes or rows of
rivets on the bottom of the boat, and in the immediate area of
the propeller(s) (Figure 1). On outboard or inboard/outboard
boats it is best to stay at least 15” (40cm) to the side of the
propeller(s).
•If possible, viewing the transom of the boat while the boat is
moving will provide the best means of locating turbulence free
water. If maximum high-speed operation is a high priority, this
is the recommended method. If this is not possible, select a
location on the transom where the hull forward of this location
is smooth, flat, and free of protrusions or ribs.
•The transducer when mounted should point straight down.
The design of the transducer will accommodate a wide range
of deadrises and remain ported straight down (Figure 2).
•On boats with stepped hulls, it may be possible to mount the transducer on
the step. Never mount the transducer on the transom behind a step, as this
area of the transom will not be in contact with the water at high speed (Figure
3).

INSTALLATION
TRANSOM INSTALLATION
•If the propeller(s) is (are) forward of the transom, itmay be impossible to find
an area clear from turbulence, and a different mounting technique or
transducer type should be considered.
Step Two -Drill the Mounting Holes
1. Remove the mounting template from the front of the Operations Manual.
2. Hold the template on the transom of the boat in the location where the
transducer will be installed (Figure 4). Align the template vertically, ensuring
the lower edge of the transom meets with the bottom corner
of the template.
3. Using a pencil or punch, mark the two mounting holes
shown on the template onto the transom. Do not mark or
drill any other holes at this time.
4. Using a 5/32” (4mm) bit drill the two holes to a depth of
approximately 1" (3cm). On fiberglass hulls, it is best to
start with a smaller bit and useprogressively larger drill bits
to reduce the chance of chipping or flaking the outer
coating.
Step Three -Assemble the Transducer
1. Attach the Pivot to the transducer body as shown in Figure
5, using the #8–3/8” (9mm) long allen headed pivot screw,
the headed pin, the two flat washers, and the two toothed
lock washers.
Note: The toothed lock washers must be positioned
between the transducer and the pivot ears. The flat
washers must be positioned to the outside at the pivot
ears.
2. Using the AIlen wrenches provided, loosely tighten the pivot
screw (Figure 6). Do not completely tighten the assembly at
this time, so the pivot angle can be adjusted later.
3. Insert the pivot/transducer assembly into the mounting
bracket as shown in Figure 7. Do not snap the assembly
closed.

INSTALLATION
TRANSOM INSTALLATION
Step Four -Mount the Transducer to the Transom
1. Apply silicone sealant to the mounting holes drilled into the transom.
2. Align the transducer assembly with the drilled holes in the transom (Figure 8).
3. Use either a flat head screwdriver, a 5/16" (8mm) hex driver, or a 5/16" (8mm)
socket to mount the assembly. Using the two #10–1”
(25mm) long slotted hex head screws, mount the transducer
assembly to the transom as shown. Do not fully tighten the
mounting screws in order to vertically adjust the transducer.
Snap the pivot down into place.
Step Five -Adjust the Running Position of the Transducer
The bracket allows height and tilt adjustment, the pivot screws
allow angular adjustment. Initially, adjust the transducer as
described in the following paragraphs. Further adjustment may
be necessary to refine the instillation after high speed testing.
1. First adjust the pivot angle of the transducer body so its
length is parallel with the length of hull of the boat. Then
pivot the transducer down so the rear is about 1/4 inch
(6mm) lower than the front (Figure 9).
2. Fully tighten the two pivot screws using the Allen wrenches.
It may be necessary to retighten the pivot screws after the
initial use as the plastics may still be seating to the lock
washers.
3. Adjust the height of the assembly so the face of the
transducer is 3/16" (4.5mm) beneath the lower edge of the
transom (Figure 10). Mark the position of the mounting
bracket on the transom with a pencil.
4. Force the pivot to the up position to gain access to the
mounting screws. Assure the transducer location has not
changed, then fully tighten the two mounting screws (Figure
11). Snap the pivot back down.
Confirm the pivot angle has not changed.
Note: A third screw location is provided for the

mounting bracket. Drill this hole and install the screw after final testing and
adjustments have been completed.