NorthStar Navigation GM1708 961XD - Manual (Page 35)

SECTION TWO - Installation
961 INSTALLATION MANUAL Revision A Page 25
The 8410 ACU has a separate black ground wire inside the coupler base,
this wire should be connected to an electrically quiet ground location.
This wire is the AC signal ground connection from the antenna input cir-
cuit. The purpose of bringing it out is to make available a separate signal
ground path. Use #16 AWG minimum for grounding. If possible, use a
grounding “strap” that is designed for this purpose.
Other electrical equipment onboard can cause large amounts of electrical
noise, even at points that appear well-grounded. Try several ground
points (ground plate, vessel ground, engine block, and so on) to deter-
mine which works best under different conditions.
Differential GPS antenna cable connectors
Both ends of the differential beacon receiver antenna cable end in UHF
connectors. To prepare UHF connectors, follow the assembly instructions
in Figure 17. For best results, coat these connectors with silicone dielec-
tric grease (DC 4 or equivalent) to protect the connector junction against
water intrusion and surface corrosion of the contacts.
In addition, the connector area including the shield-to-connector junc-
tion and jacket-to-crimp ferrule area can be protected with liquid electri-
cal tape (Starbright Liquid Tape comes in color-coordinating black or
white), or self-vulcanizing electrical tape (Tommy Tape).
WARNING!
Whenever any antenna is disconnected from on-board equip-
ment, be sure to ground the antenna shield in order to dis-
charge extremely large static voltages that can quickly build up
on an ungrounded antenna system. These voltages are haz-
ardous to personnel and equipment!