Comtech EF Data UT-4579 - Manual (Page 60)

UT4579 X-Band Up Converter MN/UT4579.IOM
Redundant System Operation Rev. 0
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A.4.4 O
FFSET
A
DJUSTMENT
The offset is used to compensate for cable and switch losses. When the system is initially
set up and tested, each converter needs to be forced to backup and the offset adjusted to
minimize gain mismatch between the normal and bypassed mode. This offset will be
different for each converter and is stored in a table in the backup unit.
Set the offset as follows:
1 Connect a signal source to the input and a power meter or spectrum analyzer to the
output of the first online converter. Record the output power.
2 Force a backup of the first online unit and adjust the offset until the output power
matches what was recorded in step one.
3 Restore the online unit and repeat for the other online units.
A.4.5 R EDUNDANCY S YSTEMS - C ONVERTER R EMOVAL
In a redundancy system, to remove an “inline” converter for repair the following
procedure must be used:
1 Force backup of faulted unit.
2 Turn the power switch on the inline converter rear panel to OFF, and remove the power
cord from the converter. DO NOT disconnect the RF and IF cables from the TSM
Module.
3 Unscrew the mounting screws on the TSM Module first, and then unscrew the rack
mounting screws on the front panel of the converter.
4 From the rear of the inline converter, hold the TSM Module and push the converter to
the front of the rack until TSM Module is free of the converter chassis.
5 Remove the inline converter from the front of the rack.
To install the replacement unit, the following procedure must be used:
1 Power up the new unit on the bench.
2 Configure the new unit for the correct redundancy settings (Redundant = ON, Address =
match old unit).
3 Power off the new unit.
4 Remove existing personality module from the new unit.
5 Carefully install the new unit into the rack. The existing module in the rack will be
plugged into the new unit.
6 Power up the new unit and un-force the backup.