Recommendations
98-166784-A
Appendix B: Ground and RF protection
B-3
BBBB
Grou
nd
an
d
RF
Per used jumper cable the maximum cable length of the cable to the antenna is reduced by:
• Enviroflex 400: 1.25 m
• SPUMA 400-FR: 6 m
• SUCOFEED 1/2" FR: 10 m
B.2.2
To ground the ADU
To ground the ADU do as follows:
1. Ground the ADU to the ship/hull via one or more of its mounting bolts.
2. Make sure to remove painting, dirt, grease etc. at the mounting holes in order to make
good electrical contact to the hull.
3. Use serrated washers when securing the mounting bolts and seal the joint with
protective coating to avoid corrosion.
It is always recommended to establish the shortest possible grounding path e.g. on steel
hulls the ADU should be grounded directly to the hull
2
. 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 paragraphs.
Figure B-2: Grounding the ADU
Note
For optimum grounding use the mounting bolt located closest to the ADU cable
plate, see
2. Note that the ADU ground connection is made at the same electrical ground potential as
the
PIU
.
Antenna
bottom
Serrated washer
(stainless steel)
Mounting
base
M bolt
(stainless steel)
