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WARNING: Disconnect and lockout AC primary power prior to servicing
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rear panels of drivers and PAs are mechanically keyed differently, so that Driver units
cannot be plugged into PA slots. If a driver module could be installed in a PA module
location or slot, the higher drive power present would destroy the input stages.
The modules are "hot-pluggable," meaning that they can be removed or inserted during
transmitter operation without turning the transmitter off. A disable switch is located in
the front handle of each module for this purpose. As a precaution, squeeze the handle
and observe the LEDs. If they remain illuminated, follow procedures for a shorted 50
volt switching transistor (passFET) before removing the module.
The modules self protect by automatically disabling themselves if an improper operating
condition is detected. A protection, control, and monitor (PCM) system monitors the
modules operating conditions. If all of the conditions are acceptable, upon an ENABLE
signal from the transmitter controller, the PCM system will enable the module by
switching on the 50 Volts. If a fault condition arises or the ENABLE signal is interrupted,
the PCM system disables the module by turning off the 50 Volts DC.
Descriptions of the various subsystems of Platinum modules are given below. First, the
RF signal paths of the modules are traced followed by subsystems describtions.
Refer to the cover sheet of the drawing package for your transmitter to locate the
necessary drawing numbers for the modules and subassemblies.
8.2.1 Driver Module, Low Band (Band I)
Figure 8-2 Low Band Driver Module, Simplified Block Diagram
(Refer to the Low Band Driver Amplifier Schematic, Tab 1000 in Drawing package)