User's Manual

FIPLEX • Electromagnetic Devices for Radiocommunication Systems
FIPLEX BIDIRECTIONAL AMPLIFIER - USER MANUAL
Isolation between
Donnor and
Service antenna
If the isolation is less than the amplifier gain plus
20dB safety margin, then positive feedback sufficient for
oscillation is present in the system. Such oscillations
will overdrive one or both amplifier chains and
continuously activate the AGC and overload circuitry,
shutting down amplifiers in order to prevent them from
damage.
Poor isolation can cause permanent damage to
the repeater and automatically voids warranty
conditions.
DO NOT POWER THE REPEATER IF “TO BASE” AND “TO MOBILE”
CONNECTORS ARE NOT CONNECTED TO A RADIANT SYSTEM OR IF
THEY ARE NOT TERMINATED WITH PROPER LOADS.
Every time the repeater is powered on, it starts an automatic antenna isolation
control procedure. This procedure takes around 30 seconds, during this time the repeater
is not available for traffic, after the procedure is finished two things can occur:
- Good isolation between antennas, in this case isolation control alarm will not be
present and the repeater can be operated at maximum gain.
- Poor or bad isolation between antennas, isolation control alarm will be present
and the system will set repeater gain to a safe value, the repeater can not be
operated at maximum gain.
WHILE ISOLATION CONTROL IS PERFORMED THE PRESENCE OF
UPLINK SIGNALS SHOULD BE MINIMIZED. AVOID DE USE OF MOBILE
DEVICES NEARBY THE REPEATER DURING ISOLATION CHECK.
11 Document FIP-BDAM-07-EN