Interphace ULTRASCAN PC90, Operation Manual

Page: 11 / 56

11
thru-hull transducer is mounted far off of the
centerline of the boat. At low speeds and on large
boats the effect is negligible. On smaller boats at high
speeds the drag can effect the steering. The effect
increases as the boat’s speed rises. Boats with trim
tabs can usually trim this out, but boats without trim
tabs may feel a pulling sensation toward the
transducer side of the boat.
A less intuative mounting location for the single thru-
hull transducer on a planing hull is on the centerline
just forward of midship. The goal in this mounting is
to place the transducer so that it is out of the water at
planing speed. As most transducers are aerated at
planing speeds, this removes the transducer from the
water flow preventing cavitation and steering
problems. Most applications for forward scanning
sonar occur when the boat is at low non-planing
speeds including fishing and navigating hazardous
waters. Under these lower speed conditions the
transducer is in the water.
Installing the Thru-hull Transducer
♦ Drill a 1/8” pilot hole from inside the hull to
assure access to tighten the housing nut and
clearance for the transducer cables.
♦ Use a 1-1/16” hole saw and drill the hole from
the outside. Sand or clean the area around the
hole, inside and outside to insure that the sealing
compound will adhere properly to the hull.
♦ Remove the bronze hex nut from the housing
and cable.
♦ Uncoil the transducer cable and thread it through
the hole into the inside of the hull.
♦
♦ ♦
♦ Apply a 1/8” thick layer of sealant on the upper
flat surface of the transducer, bronze alignment
pin and fairing block (if used).
♦ From the outside of the hull, push the housing
into the 1” hole. Twist the housing slightly to
squeeze out excess sealant. Carefully confirm
that the transducer is aligned so that the BLUNT
front end is pointed directly toward the front of
the boat.
♦
Install and tighten the bronze hex nut (allow for
swelling in wooden hulls) and remove excess
sealant from the outside to assure smooth water
flow over the transducer.
ULTRASCAN PC90—90-Degree Vertical and 90-Degree Hori-
zontal Scan
The single ULTRASCAN PC90 thru-hull
transducer (T1-I200-032) contains two phased ar-
rays, one used to scan vertically and the other hori-
zontally. The transducer has two cables, one con-
nected to each array and each is color coded—green
for the vertical array and blue for the horizontal
array.
Because this transducer scans horizontally,
care must be taken to locate it at a position where it
can see 45 degrees either side of the bow (see sketch
at left with side and overhead views). The horizontal
scan plan is angled downward by 10º to minimize
surface clutter.
It can be mounted in front of a fin keel, or just
off to the side of the leading edge of the keel where
unobstructed forward vertical and horizontal views
are available.
On deep full keel vessels (trawlers, etc) it is
usually not possible to find a suitable location for a
single transducer with the horizontal scan. These
vessels should install the ULTRASCAN PC180 sys-
tem with two transducers.
ULTRASCAN PC90