Motorola PTP 400 Series - Manual (Page 169)

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When using dual polar antennas the ODU should be mounted in such a position as to
minimize the cable length keeping losses to a minimum (taking into account the minimum
cable lengths required by the FCC regulations, see section 13.7 ”Antennas for 5.8GHz FCC
Regions”).
When using separate antennas the ODU should be mounted in such a position as to minimize
both cable runs between the ODU and the antennas. It is not necessary to mount the ODU at
the mid point between the antennas.
13.8.6 Antennas
The Antennas should be mounted according to the manufacturer’s instructions. Actual
antenna position will depend on the available mounting positions and link requirements. It
may be necessary to mount the antennas 20m (66 feet) apart or at a certain distance from the
ground to get the desired results.
13.8.7 Alignment Process
When aligning antennas deployed with a Connectorized version of the PTP 400 Series
Bridge, it may not be possible to hear the alignment tone emanating from the ODU. In this
case it may be necessary for a second installer to assist in the operation. Alternately it may
be possible to extend the tube on the supplied stethoscope to give a longer reach.
Tip: Fine antenna alignment can sometimes be achieved by tightening and loosening the
bolts on either side of the antenna mounting bracket, rather than trying to turn the whole
bracket on the mounting pole.
13.8.8 Dual Polar Antennas
The process for aligning a dual polar antenna is the same as aligning an Integrated unit with
an integrated antenna. This procedure is detailed in section 7.7.10 ”Aligning the PTP 400
Series ODUs”.
13.8.9 Separate Antennas
When using separate antennas to achieve special diversity it is recommended that one be
mounted with Horizontal polarization and the other with Vertical polarization.
The following steps should be followed:
Step 1: Mount the Antennas
Step 2: Mount the ODU