Product Manual

Product Manual for Tornado Radio Unit
52
Earthing kit
Earthing kits
1/2" heliax cable
Polyphase
discharge
unit
Coax to
cabinet
45º cone of
protection
Lightning protection
A gas discharge unit is required to release high voltage charges developed between the cable inner and outer.
There are two types available, a transmitting and a receiving variant. The transmitting variant is the larger. It is very
important that these variants are not confused because the lower discharge potential rating for the receiver unit will
be triggered by transmitting voltages. This will cause a high VSWR and poor performance.
8.3 INSTALLATION
Three styles of system installation are shown below. Of these, (a) has the lowest RF losses and the highest
efficiency of power supply to the RU. However, mounting of the battery equipment up the pole may be considered
a disadvantage from a mechanical or installation viewpoint. In (b), the RF losses are still low, but the DC power
losses are highest, whilst in (c) the DC losses are minimised, and access is convenient but at the expense of RF
performance. Option (b) may also be achieved using Power over Ethernet (PoE) which is described further in
section 8.2.3.9.