User Manual

Axell Wireless Limited
Technical Literature
UHF Dual Band Line Amplifier
Document Number 55-227901HBK
Issue No. 4
Date 23/06/2014
Page 24 of 30
5.1.3. Downlink
Confirm that there is a signal at the expected frequency and RF level from the proceeding cable. If
this is not present then the fault may lay outside the system.
If a signal is not received at the output it will be necessary to follow the downlink path through the
system to find a point at which the signal is lost. The expected downlink output for the given input can
be found in the end-to-end test specification.
5.1.4. Uplink
Testing the uplink involves a similar procedure to the downlink except that the frequencies used are
those transmitted by the mobile equipment.
5.1.5. Checking service
Following the repair of any part of the system it is recommended that a full end-to-end test is carried
out in accordance with the test specification and that the coverage is checked by survey.
It is important to bear in mind that the system includes a radiating cable network and base stations
that may be faulty or may have been damaged.
5.1.6. Fault repair
Once a faulty component has been identified, a decision must be made on the appropriate course to
carry out a repair. A competent engineer can quickly remedy typical faults such as faulty connections
or cables. The exceptions to this are cable assemblies connecting band pass filter assemblies that
are manufactured to critical lengths to maintain a 50-ohm system.
Care should be taken when replacing cables or connectors to ensure that items are of the correct
specification. The repair of component modules such as amplifiers and band pass filters will not
usually be possible in the field, as they frequently require specialist knowledge and test equipment to
ensure correct operation. It is recommended that items of this type are replaced with a spare unit and
the faulty unit returned to Axell Wireless for repair.