User's Manual
Page 21
E Series Ethernet Radio – User Manual
Version 08-10
Part D – System Planning and Design
Common Cable Types Loss per meter Loss per 10m
@ 450MHz @ 450MHz
RG58C/U 0.4426dB 4.4dB
RG213/U 0.1639dB 1.6dB
FSJ1-50 (¼” superex) 0.1475dB 1.5dB
LDF4-50 (1/2” heliax) 0.0525dB 0.52dB
LDF5-50 (7/8” heliax) 0.0262dB 0.3dB
RF Feeders and Protection
The antenna is connected to the radio modem by way of an
RF feeder. In choosing the feeder type, one must compromise
between the loss caused by the feeder, and the cost, exibility, and
bulk of lower loss feeders. To do this, it is often prudent to perform
path analysis rst, in order to determine how much “spare” signal
can be allowed to be lost in the feeder. The feeder is also a critical
part of the lightning protection system.
All elevated antennas may be exposed to induced or direct
lightning strikes, and correct grounding of the feeder and mast are
an essential part of this process. Gas discharge lightning arresters
should also be tted to all sites.
Note: All ETSI installations require the use of a lightning surge
arrestor in order to meet EN60950. See Part A - Preface for
lightning arrestor specications.