EQUIPMENT MANUAL FOR RF-9122 GSM900-GSM1800 FSR
RF-9122T18 QE
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Page 47
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6 MAINTENANCE
This equipment is designed for trouble free operation and generally does not need maintenance.
Maintenance activities should only be carried out by trained personnel.
The equipment operation status can be observed remotely through OMC.
Periodic inspection of the repeater equipment(s) is recommended, the recommended tasks includes:
z
Inspect and record operation status and output power of the repeater from OMC or OMT.
z
Verify the direction and position of antennas. Re-align if necessary.
z
Make sure the cable gland and sealing on the RF cable connectors are not damaged.
z
Verify lightning and grounding protection are in good condition.
z
For both Li-ion and the optional equipment back-up battery, verify their state. Deeply
discharged battery shall be return to Comba for replacement.
y
A simple procedure to check Li-ion battery: after operating for 24-hours, switch off AC
power supply. If the voltage of Li-on battery drops below 16V within one hour, the Li-on
battery has been over-discharged.
y
A simple procedure to check the back-up battery: after operating for 24-hours, switch off
AC power. If the voltage of backup battery drops below 24V within one hour, the backup
battery has been over-discharged.
6.1 REFERENCE FREQUENCY CALIBRATION
The reference frequency may drift, which affect the accuracy of Tx/Rx frequency and shifting
frequency. As part of the regular maintenance routine, check of the reference frequency is
recommended.
The diagram below shows the layout of the ‘Crystal Oscillator board’:
Crystal Oscillator
Interface Board
RP1
Crystal Oscillator
TEST
Test Port
Regulator
Potentiometer
Crystal Oscillator
Interface Board
RP1
Crystal Oscillator
TEST
Test Port
Regulator
Potentiometer
Locate the crystal oscillator interface board within the equipment; connect the ‘test port’ to a
frequency counter. The desired reading should be 10MHz.
Only if the reference frequency has drifted beyond
±
0.03Hz, make a necessary adjustment via the
multi-turn trimmer labeled ‘RP1’.
