Harris Platinum Series, Technical Manual

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30 kW Systems, 10% Aural (standard)
In a high band system, the AGC module output first passes through
a preamp. In low-band systems, the preamp is not necessary.
The resulting output drives a driver module. The driver output
is divided in a four-way divider, and fed to four parallel PA
modules. The outputs are recombined in a four-way combiner,
whose output passes through a harmonic filter on its way to the
optional diplexer.
•
30 kW Systems, 20% Aural (optional)
The aural AGC module output passes to a phase and gain
module. In a high band system, two outputs pass through
preamps; in low band, the preamps are omitted.
Each signal then passes through a driver module, whose output
is split in a four-way divider. Eight outputs are thus obtained,
each feeding the input of one of eight PA modules. The outputs
are recombined, first into two signals with a pair of four-way
combiners, then into a single output using a 3 dB hybrid. The
combined output passes through a harmonic filter before being
passed to the optional diplexer.
•
45 kW Systems, 10% Aural (standard)
In a 45 kW low band system, the AGC module output drives a
phase and gain module, whose outputs drive two driver modules.
In high band systems, preamps are added between the phase and
gain module outputs and driver module inputs.
The two signals each pass through three-way power dividers,
whose outputs feed a total of six aural PA modules. The PA
module outputs are recombined using three-way combiners and
a 3 dB quadrature hybrid, whose output passes through a har-
monic filter to the optional diplexer.
•
45 kW Systems, 20% Aural (optional)
The AGC module output feeds a phase and gain module. One of
the phase and gain module’s outputs feeds a preamp and a second
phase and gain module, creating a total of three output signals.
In a low-band transmitter, these outputs are sent directly to the
aural PA/visual driver cabinets; in a high-band system, the three
outputs pass through preamps located in the control cabinet
before passing to the amplifier cabinets.
Each of the three signals is input to a driver module, whose output
passes through a four-way splitter. This yields twelve outputs, each
of which feeds an aural PA module. Three four-way combiners
combine the twelve PA outputs into three signals. The first two are
recombined using a 3 dB quadrature hybrid, whose output is
combined with the remaining signal in a 4.77/1.76 dB asymmetri-
cal hybrid. The combined output passes through a harmonic filter
on its way to the optional diplexer.
•
60 kW Systems, 10% Aural (standard)
The AGC module output feeds a phase and gain module. In high
band systems, the two outputs are then fed to two preamps. In
low band transmitters, the preamps are not necessary.
Each of the two outputs feeds a driver module. The driver
outputs are each split in four-way dividers, for a total of eight
outputs, and the outputs drive an array of eight PA modules.
The PA outputs pass to four-way power combiners, whose
outputs are combined in a 3 dB quadrature hybrid used as a
two-way combiner. The combined output passes through a
harmonic filter before being sent to the optional diplexer.
•
60 kW Systems, 20% Aural (optional)
The AGC module output passes through a phase and gain
module, whose outputs pass to two preamps. The preamp out-
puts are each divided in half, using 3 dB hybrids, producing a
total of four outputs which are sent to the aural cabinet.
Each signal feeds one of four driver modules, whose outputs
feeds four-way splitters. The outputs drive sets of four paralleled
PA modules, for a total of 16 PA modules.
The outputs are recombined in the same manner in which the
inputs were divided: four four-way combiners are used. Then,
the four outputs pass to two 3 dB quadrature hybrids, whose two
outputs are finally combined in another 3 dB hybrid. The com-
bined output passes through a harmonic filter on its way to the
optional notch diplexer.
1.2.10.6
Parallel Aural Drive Paths
As in the visual path, parallel aural drive paths are available as
an option on many models to eliminate the possibility of a
single-point aural drive failure.
In some lower power transmitters, the option consists of using
a two-way divider and a two-way combiner, plus two driver
modules, to replace the single driver module found in standard
systems. In transmitters 15 kW and higher, a switchable 6 dB
pad is added before the two-way splitter, which is controlled by
the slave controller in the aural cabinet.
1.2.11
Transmitter Output Networks
The transmitter output network performs three functions: filter-
ing harmonics from the outputs, removing color subcarrier
remnants from the vestigial sideband, and combining the aural
and visual outputs into a common antenna feed for transmission.
Two common configurations exist:
•
1-10 kW Systems
A combination color notch filter/notch diplexer (optional) receives
the aural and visual outputs and combines them. The output then
passes through a harmonic filter to the antenna system.
•
15-60 kW Systems
Two harmonic filters are used: one in the visual path, and one in
the aural path. The output of the visual harmonic filter feeds a
color notch filter. The outputs of the aural harmonic and visual
color notch filters feed a notch diplexer (optional), whose output
passes to the antenna system.
1.3
Specifications
Table 1-1 contains the transmitter specifications.
NOTE
These specifications are subject to change without notice.
1-6 888-2365-001
WARNING: Disconnect primary power prior to servicing.