User Manual

Table Of Contents
Axell Wireless Limited
Technical Literature
15 Channel UHF Hybrid Select Repeater
Document Number 50-157401HBK Issue No. 1 Date 26/03/2008 Page 30 of 50
4.4. 100W Power Amplifier 80-245103
The 100W Power Amplifier shelf (80-245103) is a Class A 100W TETRA Linearised Class A amplifier
where 4, 25W linearised power amplifier modules (Pair “A” and Pair “B”) are combined together in a
parallel/phased configuration. Its housing is a 4U, 19” Rack mount tray with SMA connectors for the
RF input/output, 2 D-Type connectors for the alarm function and 2 DC connectors with fuse for the 24
DC supply. Its cooling is realized by fans mounted on the front panel.
It has a built in Current Fault Alarm Function with the four amplifiers in two summary alarm paths. The
summary alarm on D connector ‘A’ will show an alarm for the two amplifiers mounted on the top of the
shelf (Pair “A”) The summary alarm on D connector ‘B’ will show an alarm for the two amplifiers
mounted at the bottom of the shelf (Pair “B”).
The downlink signal is received from Downlink Splitter/Combiner 50-157402 via the SMA port on the
front panel labelled “RF INPUT” and the signal is split into two paths by a 3dB splitter/Combiner 05-
002603, one path is routed to Amplifier Pair A and the other is routed to Amplifier Pair B. Each signal
path is then further split by another pair of 3dB splitter/Combiners 05-002603 providing one path for
each of the four Amplifier Modules.
The four separate paths are then each passed through their respective Amplifier Modules 12-026901,
this configuration provides double redundancy, so should any of the 25W driver amps fail, coverage
would still continue, albeit with a slight loss in power.
After leaving the Amplifier Modules each pair of paths is then combined by a pair of 3dB
splitter/Combiners 05-002603 the resultant two paths are then combined by a further 3dB
splitter/Combiner 05-002603 and the combined signal then leaves the Amplifier Shelf to return to the
Downlink Splitter/Combiner 50-157402 via the SMA port on the front panel labelled “RF OUTPUT”