Cambium PTP 670 Series, Руководство пользователя

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Chapter 5: Installation Installing the Trimble Accutime GPS receiver
Page 5-36
Connecting the GPS drop cable
Use this procedure to connect the GPS drop cable to the GPS unit and supporting structure.
1 If a GPS adapter cable is available, use it to connect the main GPS drop cable to the GPS unit:
2 If a GPS adapter cable is not available, connect the main GPS drop cable to the GPS unit via a 12
way circular connector. Weatherproof the connection as follows:
• Wrap a layer of self-amalgamating tape, starting 25mm below the bared back outer of the
cable and finishing at the GPS housing.
•
Wrap a layer of PVC tape, starting just below the start of the self-amalgamating tape and
finishing at the GPS housing, overlapping at half width.
•
Repeat with four more layers of PVC tape alternating the start and finish ends.
3 Lay the main drop cable as far as the building entry point, ensuring there is enough length to
extend through the wall of the building to the LPU.
4 Attach the main GPS drop cable to the supporting structure using site approved methods.
5 Ground the GPS drop cable to the supporting structure at the points shown in Figure 43 (wall
installation) or Figure 44 (mast or tower installation):
• For standard grounding instructions, see Creating a drop cable grounding point on page 5-
56 .
•
If a GPS adapter cable has been installed, see Top grounding point for GPS adapter cable on
page 5-36 .
Top grounding point for GPS adapter cable
If a GPS adapter cable has been installed ( Figure 121 ), use this procedure to ground the drop
cable at the point where the solid screen is already exposed, and weatherproof both the
ground cable joint and the RJ45 connection.