Eagle Electronics 640c Fish Finder User Manual


 
14
Remember, transducer location is the most critical part of a so-
nar installation.
Recommended Tools and Supplies
If you prefer the option of routing the cable through the transom, you
will need a 5/8" drill bit. (If you intend to install an additional speed or
temp sensor and route its cable through the same hole in the transom,
you will need a 1" (25.4 mm) drill bit to accommodate all the cables.)
NOTE:
The following installation types also call for these recommended
tools and required supplies that you must provide (supplies listed
here are not included):
Single-frequency transom installations
Tools include: two adjustable wrenches, drill, #29 (0.136") drill bit, flat-
head screwdriver. Supplies: none.
Dual-frequency transom installations
Tools: two adjustable wrenches, drill, #20 (0.161") drill bit, flat-head
screwdriver. Supplies: four, 1" long, #12 stainless steel slotted wood
screws.
Single-frequency trolling motor installations
Tools: two adjustable wrenches, flat-head screwdriver. Supplies: plastic
cable ties.
Shoot-through hull installations
Tools: these will vary depending on your hull's composition. Consult
your boat dealer or manufacturer. Other tools are a wooden craft stick
or similar tool for stirring and applying epoxy, and a paper plate or
piece of cardboard to mix the epoxy on. Supplies: rubbing alcohol, 100
grit sandpaper, specially formulated epoxy adhesive available from LEI
(see ordering information on the inside portion of the back cover). A
sandwich hull also requires polyester resin.
Selecting a Transducer Location
1. The location must be in the water at all times, at all operating speeds.
2. The transducer must be placed in a location that has a smooth flow of
water at all times. If the transducer is not placed in a smooth flow of
water, interference caused by bubbles and turbulence will show on the
sonar's display in the form of random lines or dots whenever the boat is
moving.
NOTE:
Some aluminum boats with strakes or ribs on the outside of the
hull create large amounts of turbulence at high speed. These boats