User Manual

AS4000 Survey Tool
605-0000-429
Issue 1.6. Date 1/9/99
TAD-005
Page 1 of 2
CRU SITE SELECTION
1. The following factors should be taken into account to determine the installation
position for the CRU:
a) The CRU should be installed as high as possible on the wall facing in the
direction of the CT. Mounting height should normally be 5-7 metres above
ground level.
b) Inspect the suitability of the wall structure for the installation position of the
CRU mounting.
Typical acceptable structures are:-
• Secure brick walls
• Concrete cladding covering Building Blocks
• Metal / Wooden pole, with suitable bracket.
d) For efficient and reliable service it is suggested that the external mounting location of
the CRU be chosen such that once ‘panned’ for optimum signal level it observes the
following criteria:-
• Avoid aligning the CRU directly toward an obstruction within a distance of
15 metres from the CRU installation point.
• Avoid obstructions such as adjacent walls or overhanging roof eaves, within
15° in the horizontal plane (see figure 1) and 30° in the vertical plane (see
figure 2).
• Ensure adequate clearance is allowed for ‘panning’ the CRU.
• The CRU is capable of being ‘panned’ with at least 15° of adjustment
either side of the direction of the CT Antenna.
• Note: Trees exceeding a distance of 50 metres from the CRU are considered
to have a minimum impact to the units performance.
2. In circumstances when these criteria above cannot be met. e.g. the panned angle violates
the criteria set out above then it is recommended to mount the CRU on a pole located
near to the property. The maximum length of drop cable is 80 metres and the distance
from the dwelling to the pole should not exceed 40 metres. The survey tool should be
used to locate a suitable position for the pole.