Furuno FELCOM251, Installation Manual

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4. GROUNDING AND RF PROTECTION
4-6
4.4.2 Grounding the Antenna Unit
You can ground the antenna to the ship/hull via one or more of its mounting bolts.
Make sure to remove painting, dirt, grease etc. at the mounting holes in order to make
good electrical contact to the hull. Use serrated washers when securing the mounting
bolts and seal the joint with protective coating to avoid corrosion.
If you are using vibration isolators at the bolts, the grounding connection between the
mounting surface and the bolts is not sufficient. In that case mount a separate ground-
ing wire. See section 4.9.
It is always recommended to establish the shortest grounding path as possible e.g. on
steel hulls the antenna should be grounded directly to the hull
*
. However, due to the
fact that this is not possible on e.g. fibreglass hulls (nor is it preferable on aluminium
hulls) a number of alternative grounding methods are suggested in the following sec-
tions.
*: Please note that the antenna ground connection is made at the same electrical
ground potential as the Communication Unit.
10 mm spacer
Antenna bottom
Mounting base
Serrated washer
(Stainless steel)
M10 Mounting bolt
(Stainless steel)