PMP Synchronization Solutions User Guide
Installing a CMM4
PMP-0297 007v001 (January, 2017)
3-51
Cabling the GPS Antenna
Connect the GPS coax cable to the female N-connector on the GPS antenna. Information on the
coax cable is covered on page
. Weatherproof the connection following
Weatherproofing an N-type antenna connector
The following procedure should be used to weatherproof the N type connectors fitted to the GPS
module and outdoor CMM installation connectors. This procedure must be followed to ensure
that there is no moisture ingress at the N-type port.
N type connectors should be tightened using a torque wrench, set to 15 lb in or 1.7 Nm. If a
torque wrench is not available, N type connectors may be finger tightened.
To weatherproof an N type connector, proceed as follows:
Figure 51 Weatherproofing an N-type antenna connector
1
Ensure the connection is tight. A torque wrench should be used if available:
2
Wrap the connection with a layer of 19 mm (0.75 inch) PVC tape, starting 25 mm
(1 inch) below the connector body. Overlap the tape to half-width and extend the
wrapping to the body of the AP. Avoid making creases or wrinkles
3
Smooth tape edges
4
Cut a 125mm (5 inches) length of rubber tape (Scotch 3M Professional Grade: D.C.J.
No. 06147 or equivalent)
5
Expand the width of the tape by stretching it so that it will wrap completely around
the connector and cable
6
Press the tape edges together so that there are no gaps. The tape should extend
25mm (1inch) beyond the PVC tape
7
Wrap a layer of 50 mm (2 inch) PVC tape from bottom to top, starting from 25 mm
(1 inch) below the edge of the self-amalgamating tape, overlapping at half width
8
Repeat with a further four layers of 19 mm (0.75 inch) PVC tape, always overlapping
at half width. Wrap the layers in alternate directions:
Second layer: top to bottom.
Third layer: bottom to top.
Fourth layer: top to bottom.
Fifth layer: bottom to top.
The bottom edge of each layer should be 25 mm (1 inch) below the previous layer.
