Codan 3048, Руководство по установке

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I
NSTALLING THE ANTENNA
G
ENERAL
3048 T
UNED
D
IPOLE
A
NTENNA
I
NSTALLATION
H
ANDBOOK
15
When installing an antenna on roof-tops where there is no existing
earth plane, an earth plane should be installed. The earth plane
should be a conducting surface extending several wavelengths in
all directions around the antenna. This can be provided by placing
a screen of wire mesh or similar material over the roof of the
building. Usually, a counterpoise system is used to provide an
efficient earth plane. A radial earth plane for an antenna mounted
on the roof-top of a building can be supplied by Codan (Codan part
number 15-00159).
If an earth plane, such as a counterpoise, cannot be provided for the
antenna, an earth wire connected to a suitable earth stake can be
used, but with reduced efficiency.
NOTE:
As the earth wire forms part of the antenna system,
any resistance in the earthing network reduces the
efficiency of the antenna.
CAUTION:
The earth connections are subject to corrosion and
oxidation. All joints must be clean, and the hardware
adequately tightened. The joints can be protected by
the application of silicone grease. In severe
conditions, joints should be covered with
self-amalgamating tape followed by a layer of good
quality UV-stable PVC tape.
CAUTION:
RF earthing should not be relied upon to provide
protective earthing. It can fail upon the removal of
one of the interconnecting links. A separate wire
should always be connected to the item that you want
to protect.