Radio Frequency Grounding Or Counterpoise; Connecting Rf Cables - Additional Information - Acom 04AT Operating Manual

2.5.3 RADIO FREQUENCY GROUNDING OR COUNTERPOISE

This grounding is used for protection from transmitted/induced RF signals, and pos-
sible radio frequency interferences. It will not protect you from a possible lightning
strike or currents with mains frequency. These may be e.g. RF counterpoises (radials),
which, in particular, could even be isolated from the ground. When they are placed
at the required height and have the proper length, they can resonate and be much
more effective for RF emission and protection than a direct connection to the ground.
However, this only applies to radio frequencies. They have no protective functions
against electric shock from currents with mains frequency, or lightning.
2.6 CONNECTING RF CABLES – ADDITIONAL INFORMATION
All connections between the tuner and the radio station should be executed in the se-
quence described below, before the tuner is powered from the amplifier.
Before you start connecting the coaxial cable from the ra-
dio station to the tuner, ensure that its two ends are not
connected to anything and take all necessary precautions
that no one has access to them! Place warning signs at
both ends reading: WARNING! DO NOT TURN ON – PEO-
PLE WORKING!
a) Before doing anything else, connect the tuner's grounding terminal.
Do not proceed with the installation, unless you have con-
nected the tuner grounding terminal marked GROUND
to the lightning protection grounding or the radio station
grounding system, according to tuner installation location,
see S. 1.5.
Before connecting any cable to the tuner, use a voltmeter
to make sure there is no AC or DC voltage above 12V from
the pin of the cable connector to the grounding terminal
of the tuner, from the ring of the cable connector to the
grounding terminal of the tuner, and between the connector
pin and ring!
b) Assign the antenna numbers (1 to 4) in advance. After verifying that there is no dan-
gerous voltage, connect, one at a time, all available antenna cables to the respective
antenna sockets, ANTENNA 1 to ANTENNA 4 of the tuner, without fastening the con-
nector rings at first, so that the cables may still be axially turned and adjusted.
20 20
CAUTION
WARNING HIGH VOLTAGE
WARNING HIGH VOLTAGE