KVH Industries TracPhone FB250 Installation Manual page 140

Terminal grounded at a dedicated RF ground (alternative)
In this case the antenna is grounded with a separate ground cable. The
ground cable must be routed parallel and close to the shielded coax cable
connecting the antenna to the terminal grounding kit. A tinned heavy gauge
wire (min. 6 mm2) can be used for this purpose - see page 133.
Note
The antenna must be electrically isolated at its mounting bolts by
means of shoulder bushes and washers ensuring the isolated RF
ground - see page 136.
(electrically bonded
to the steel hull)
Appendix C: Grounding and RF protection
Recommended
Antenna
Base Plate
(electrically bonded to
the hull though the mast)
Antenna grounded
with mounting bolts
Mast
Alternative grounding for steel hulls
Alternative
Antenna
Base Plate
(Antenna isolated
from the the hull )
Antenna grounded
with separate cable
Mast
(electrically bonded
to the steel hull)
127