KVH Industries TracPhone FB250 Installation Manual page 149

Appendix C: Grounding and RF protection
C.9.3 Isolation of the antenna from the mounting base
In cases where the antenna is to be isolated from the mounting base, shoulder
bushes and washers (accessories) must be used as illustrated below. Please
note that the isolation has to be implemented on all four mounting bolts
(including the bolt securing the ground cable).
Isolating washer
136
Isolating shoulder bush
Separate ground cable
Plain washer
(stainless steel)
Spring washer
(stainless steel