User's Guide

Table Of Contents
10 Connectorized PTP 500 Series Bridge
182
10.5.4 Cable Losses (FCC Regions Only)
The FCC approval for the product is based on tests with a cable loss between the units of not
less than 1.2 dB at 5.8 GHz. The use of lower cable losses would result in the installation
being outside the FCC rules. As an indication, 1.2 dB of cable loss corresponds to the
following cable lengths, excluding connector losses (source: Times Microwave).
Table 20 - Cable Losses per Length
Length for 1.2dB Cable Loss at 5.8 GHz
Cable
(ft) (m)
LMR100 1.9 0.6
LMR200 4.6 1.4
LMR300 7.25 2.2
LMR400 11.1 3.4
LMR600 16.5 5.0
10.6 Antenna Choices
The main selection criterion is the required antenna gain. The secondary criterion is the ease
of mounting and alignment. For example, the Radio Waves Parabolic dishes are supplied with
a mount that allows adjustment for alignment independent of the actual antenna mounting.
This type of antenna is much easier to align than those that have to be rotated around the
mounting pole for alignment.
In non-FCC regions, antenna choice is not restricted, but any region specific EIRP limit must
be obeyed by reducing the maximum Transmit power, see Section 4.2 “Licenses and Region
Cod
es” and Section 10.5 “Regulatory Issues with Co
nnectorized Units”.
In FCC regions, antenna choice is restricted as described in Sections 16.2.8 “PTP 54500
FCC Antenna
Restrictions” and 16.3.8 “PTP 58500 FCC Antenna Restrictions”.
The maximu
m permitted antenna gain depends upon product variant as follows:
PTP 58500: 37.7 dB
PTP 54500: 34.9 dB