Furuno 1731 MARK 3, Operator'S Manual

Page: 62 / 83

6-2
Flat washer
Spring washer
M10 x 25 Hex bolt
Platform
4- 12 Holes
Cable
entry
Ship's bow
(1) This signal cable run between the antenna and the display comes in lengths of 10 m, 15 m, 20 m
and 30 m. whatever length is used it must be unbroken; namely, no splicing allowed.
(2) Deposits and fumes from a funnel or other exhaust vent can adversely affect the aerial
performance and hot gases may distort the radiator portion. The antenna unit must not be
mounted where the temperature is more than 70°C
Mounting the antenna
1. Open the antenna unit packing box carefully.
2. Unbolt the four bolts at the base of the radome to remove
the radome cover.
Antenna unit
The mounting surface must be parallel with the waterline and provided with five holes whose
dimensions are shown in the outline drawing attached at the end of this manual.
The unit is adjusted so a target echo returned from the bow direction will be shown on the zero
degree (heading line) position on the screen. When drilling holes, be sure they are parallel with the
fore and aft line.
3. Prepare a platform of 5 to 10 millimeters in thickness for the antenna unit.
A mounting bracket for mounting the antenna unit on a sailboat mast is optionally available.
(Refer to page 1-9.) Find the cable entry on the radome base. Next, position the radome base so
the cable entry faces the stern direction. This alignment must be as accurate as possible.
Antenna unit, cover removed Antenna unit How to fasten the radome base to the
mounting platform
Wiring and final preparation
4. Drill a hole of at least 20 millimeters diameter through the deck or bulkhead to run the signal
cable between the antenna unit and the display unit. (To prevent electrical interference avoid
running the signal cable near other electrical equipment and in parallel with power cables.) Pass
the cable through the hole. Then, seal the hole with sealing compound for waterproofing.
5. Remove two shield covers in the radome.
6. Remove the cable clamping plate by unfastening four screws and removing a gasket.
Radome cover
Flat
washer
Spring
washer
Platform
Antenna base plate
M10 x 25
Hex bolt
Radome
5 - 10 mm
Apply silicone sealant.
Effective
thread length
25 mm
Gasket