20
2. Next, take the transducer out of the water and place it in the water in
the sump of the boat, face down. (The transducer face is shown in the
figure on the following page.) Notice how the signal strength de-
creases. The second bottom signal will probably disappear and the bot-
tom signal intensity will likely decrease.
3. Now move the transducer around to find the best location with the
strongest possible bottom signal. If you find a spot with an acceptable
bottom signal, mark the location and move on to step 4.
If you can't get an acceptable bottom signal, try turning up the sensi-
tivity by three or five keystrokes and then move the transducer around
once more. If you find a spot that works, mark it and move on to step 4.
If you have to turn up sensitivity by more than five keystrokes to get a
good signal, the transducer should be mounted on the outside of the
hull. This is especially true if you have to turn sensitivity all the way
up to get a decent bottom signal.
4. Most people can get good results by following steps 1 through 3, so this
step is optional. If you want to make an extra effort to be absolutely sure
that your selected location will work under all conditions, make a test
run with the boat on plane and observe the bottom signal. You'll need to
figure some way to prop the transducer into position while you make
your test run. (A brick or two might be sufficient to hold it in place.)
5. When you're satisfied with a location, mark it and proceed with
the installation.
Shoot-thru-hull Installation
If you are installing the transducer on a hull with floatation material
sandwiched within the hull, refer to the text "Hulls With Flotation Ma-
terials" beginning on page 18.
1. Make sure the area is clean, dry and free of oil or grease, then sand
both the inside surface of the hull and the face of the transducer with
100 grit sandpaper. The sanded hull area should be about 1-1/2 times
the diameter of the transducer. The surface of the hull must be flat
so the entire transducer face is in contact with the hull prior to
bonding. After sanding, clean the hull and transducer with rubbing
alcohol to remove any sanding debris.