User's Manual

Other faults
Open the repeater cover and connect an OMT32/PC to the repeater.
Open the Repeater Event Log and check the cause of the alarm.
• If an antenna isolation alarm is indicated, the antenna isolation should
be measured. It should be 10dB - 15dB higher than the repeater gain.
Check the antenna installation to ensure that nothing has happened to
it. If there is a permanent degradation of the antenna isolation, lower
the gain to 15dB below the measured antenna isolation.
Make an alarm reset.
• If the alarm is activated by an external alarm input, then remove the
cause of the alarm.
• If the alarm is indicated as RF blocking, then an external strong CW
signal can be the cause of the alarm.
The CW signal is described in the Channel Selective GSM Repeater
section under Operational Status in Chapter 10.
• If a PSU alarm is activated which appears again, then the PSU should
be replaced.
• If the alarm is internal and appears again, then a fault has probably
occurred in the repeater. Try to trace which unit has activated the
alarm and the type of the alarm. In most cases, the unit and fault type
can be detected.
• As the last resort, if nothing else helps, remove the repeater for service.
ALLGON System AB AR Repeaters & OMT32 Troubleshooting
User’s Manual VD202 90/EN Rev. 1A 1999-07 12 - 3