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 35 of 50
4.5. Uplink Triplexer Shelves 50-157405
There are two Triplexer Shelves in the system; both are in the Uplink path. Each Triplexer is housed
in a 4U, 19” Rack Mount Tray and they provide passband definition for the three uplink signal paths.
Triplexer 1 (the Uplink Splitting Triplexer) is positioned before the 5W Amplifier Shelves 50-157406
and serves to split the signal from the LCX Cables into three paths, one each for each of the 5W
Amplifier Shelves. Triplexer 2 (the Downlink Combining Triplexer) is positioned after the 5W Amplifier
Shelves 50-157406 and serves to combine the three signals from the 5W Amplifier Shelves into a
single path which is then passed to the TX Antenna.
The Uplink signal arrives at Triplexer 1 from the Downlink Splitter/Combiner 50-157402 via the port
labelled “N”, the signal is split by means of critical length harness into three paths and each path is
then fed through a bandpass filter (02-013401 and 02016801) which are tuned to the required
passband frequency and rejects out-of-band noise. The three passbands are:
Channel 1 412.950 to 413.650MHz
Channel 2 415.880 to 417.200MHz
Channel 3 419.050 to 420.000MHz
The Bandpass filters employed on Channels 1 and 3 are 02-013401, the bandpass filter on Channel 2
is 02-016801 as this a wider bandwidth.
After exiting the Bandpass Filters the three Uplink signal paths leave the Triplexer,
Channel 1 via the port labelled “G”
Channel 2 via the port labelled “H”
Channel 3 via the port labelled “J”
The three signal paths then go to their respective 5W Amplifier Shelves.
After leaving the 5W Amplifier Shelves the three uplink signal paths enter Triplexer 2
Channel 1 via the port labelled “K”
Channel 2 via the port labelled “L”
Channel 3 via the port labelled “M”
Each path is then fed through a bandpass filter (02-013401 and 02016801 in the same order as in
Triplexer 1) which are tuned to the required passband frequency and rejects out-of-band noise.
After passing through the Bandpass Filters the three signals are combined by means of critical length
harness into a single path which then exits the Triplexer via the port labelled “TX ANT” and is fed up
to the port in the top of the rack also labelled “TX ANT” where the connection is made to the TX
Antenna