- 7 -
- 7 -
After installing the head-end station, retrofitting accessories or installing
modules it is necessary to tighten all cable connections, F terminals and
cover screws in order to maintain compliance with current EMC regulations
and to ensure a reliable operation.
4 Setting the FM amplifier
In order to prevent interference, too high signal levels, e. g. of local transmitters,
can be reduced by absorption circuits.
• Switch on the head-end station.
—> The display shows the following indication for the FM amplifier.
If the module is not indicated update the software of the control panel.
• Connect a spectrum analyser to the output
C
of the FM amplifier.
• Set level regulator
1
to the mechanical centre.
• If necessary tune the absorption circuit groups
2
and
3
to the frequencies
to be lowered.
—> You can lower 3 interfering frequencies each with the absorption circuit
groups
2
and
3
. If the adjustment range of an absorption circuit, for
example from group
2
is inadequate, you can lower the frequencies
even further with an absorption circuit that is tuned to the same frequency
from group
3
.
Box 1
87.5 - 108
UKW
!
Fig. 4
