User Manual

Axell Wireless Limited
Technical Literature
L.A. M.T.A. Remote Sites
Document Number 80-301401HBKM Issue No. 1 Date 13/06/2008 Page 143 of 148
3) Carefully disconnect the RF input and output coaxial connectors (usually SMA)
If alarm board removal is not required, go to step 5.
4) There is (usually) a plate attached to the alarm board which fixes it to the amplifier, remove its
retaining screws and the alarm board can be withdrawn from the amplifier in its entirety. On
certain types of amplifier the alarm board is not
mounted on a dedicated mounting plate; in this
case it will have to firstly be removed by unscrewing it from the mounting pillars, in most
cases, the pillars will not have not have to be removed before lifting the amplifier.
5) If the amplifier to be removed has a heatsink attached, there may be several different ways it
can have been assembled. The most commonly used method, is screws through the front of
the heatsink to threaded screw holes (or nuts and bolts), into the amplifier within the main
case. If the heatsink is mounted on the rear of the main case (e.g., against a wall in the case
of wall mounted enclosures), then the fixing method for the heatsink will be from within the
case, (otherwise the enclosure would have to be removed from the wall in order to remove the
heatsink).
When the heatsink has been removed, the amplifier may be unscrewed from the main casing by its
four corner fixings and gently withdrawn.
Fitting a new power amplifier module will be the exact reverse of the above.
Note Do not forget to apply fresh heatsink compound to the heatsink/main case joint and
also between the amplifier and the main case.
6.3.5 Low Power Amplifier Replacement
1 Disconnect the mains power supply and disconnect the 24V dc supply connector for the LPA.
2 Disconnect the RF input and output cables from the LPA.
3 Disconnect the alarm connector.
4 Remove the alarm monitoring wires from (D type connector) pins 9 and 10.
5 Remove the LPA module by removing the four retaining screws, replace with a new LPA
module and secure it with the screws.
6 Connect the RF cables to the LPA input and output connectors. Reconnect the wires to the
alarm board connector pins 9 and 10.
7 Reconnect the DC supply connector and turn the mains switch on.
Note Tighten SMA connectors using only a dedicated SMA torque spanner. If SMA connectors are
over-tightened, irreparable damage will occur. . Do not use adjustable pliers to loosen/tighten SMA
connectors.
Also take care not to drop or knock the module as this can damage (or misalign in the case of tuned
passive modules) sensitive internal components. Always store the modules in an environmentally
friendly location
6.3.6 Module Transportation
To maintain the operation, performance and reliability of any module it must be stored and
transported correctly. Any module not installed in a whole system must be kept in an anti-static bag or
container. These bags or containers are normally identified by being pink or black, and are often
marked with an ESD label. Any module sent back to Axell for investigation/repair must be so
protected. Please contact Axell’s quality department before returning a module.