Rf Combining; Control System - Harris Platinum Z2 CD Manual

Introduction/Specifications
The IPA consists of a standard PA Module with one PA on each side of the heatsink.
Only one half of the IPA module is active at a time to provide the required drive to
the PA. The transmitter contains sensing, logic and switching circuitry which will
automatically switch from a failed IPA to the remaining one. For even further
redundancy, any PA module can also be used as an IPA module, without
modification.
1.3.5
All 8 PAs are combined in a compact, "Z plane" isolated combiner. True isolation
means that each module will continue to work into a nominal 50 ohm load
regardless of the number of active amplifiers, for almost zero stress to the amplifiers
during fault conditions. The output of the 8 way combiner is then filtered by the
transmission line filter before leaving the transmitter. Directional couplers and a
customer RF demodulator sample are provided.
1.3.6
A microprocessor based controller monitors over 100 operating functions of the
transmitter and makes intelligent operating decisions based on operating conditions.
Detailed system information is available using the front panel diagnostic display.
The controller is designed for direct connection to standard parallel remote control
systems.
The Controller also includes built-in logic and controls for automatically switching
to the reserve IPA section, and a backup exciter if installed. The main controller
provides automatic power control, VSWR overload protection, automatic VSWR
foldback, RF power soft start, AC restart and diagnostics. Basic control functions
available even without the main controller are VSWR protection, IPA protection,
transmitter on/off, failsafe and interlock.
The control system for the transmitter is modular and is centered on the backplane
which is also the control panel for the transmitter. Various control printed circuit
boards are plugged into the backplane to fit the transmitter for the configuration
being supplied.
The control system front panel includes an output metering LCD display which can
be used to view power output, VSWR, PA voltage and PA current. A second LCD
window, the Diagnostics Display, permits extensive viewing of internal voltages,
temperatures and a detailed Fault Log to easily pin-point problems. Long-life LED
fault and status indicators and reliable membrane switches provide all needed local
control and selection for the transmitter.
1-4
WARNING: Disconnect primary power prior to servicing.

RF Combining

Control System

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