Furuno FELCOM 250 Installation Manual page 10

Compass safe distance
Locating the antenna unit too close to a compass can affect the compass performance. Keep the
compass safe distance to prevent interference to the magnetic compass. See page i.
Other mounting guidelines
Other important mounting guidelines are
• Locate the antenna unit away from exhaust stacks (foreign material on the radome can interfere
with reception and transmission).
• Keep the unit away from heat sources.
• Locate the unit away from places where fuels and chemical solvents are stored.
• Keep in mind the length of the cable from the communication unit is maximum 100 meters
(when coaxial cable 12D-SFA-CV is used).
Guardrail, platform
To facilitate servicing, construct a mast of about one meter (40") in height. (See page 5.) The para-
graphs which follow provide guidelines for selection and construction of the mast.
Fit the mast with a guardrail and platform (or steps), for serviceman's safety. (In most installations
the serviceman stands on the platform while checking the radome. Thus this distance should be
secured for ease of servicing.) The height of the guardrail should be as tall as possible to ensure
safety.
Mast strength
The mast material must be sufficiently strong to meet the
demands of the marine environment. It should satisfy the
following requirements.
• It must be able to support radome mass plus at least 2.5
cm (1") of ice and snow. Special consideration should
be given if the unit is operated in areas of heavy snow or
freezing temperature.
• The mast bending moment must be able to withstand
expected maximum pitching, rolling and wind pressure.
• To prevent resonance at low frequencies (approximate-
ly 5 Hz), four stays can be fixed between the mast and
the mounting base.
Antenna unit mass
Platform, guardrail mass
Expected ice and snow
Maximum wind pressure (at wind speed 56 m/s)
Item
1. HOW TO INSTALL THE UNIT
Wind
Pressure
(Above figure: FELCOM 500)
FELCOM 500
21 kg (46 lb) ± 10%
280 N
4
FELCOM 250
6.5 kg ± 10%
36.3 N