User's Manual Part 2

Power Amplifier Module - 106 -
®
Affinity LBD-200C-N1 Transmitter
Product Manual
14 Power Amplifier Module Description
The Power Amplifier (PA) Module amplifies the inputted Driver signal to the power level
required for transmission. The PA Modules operate in tandem with other PA Modules to obtain
the required power level for the transmitter. The PA Modules are plugged into the backplane of
the Sub-Chassis assembly and operate in an RS-485 multi-drop environment. Each module
contains a unique logical address that allows for operation, control, and monitor activities within
the transmitter system. An RS-232 port located on the front panel of the PA Module is provided
for module setup, historical record extraction, and diagnostic feedback. A POWER/FAULT
status indicator and the ON/LOCKED, OFF/UNLOCKED key assembly is also located on the
front panel of each PA Module. The key-lock assembly provides physical and electrical
connection.
Operational power required by the PA Module is derived from the Front-End Power Supply. This
48V
DC drives the voltage regulators that produce the voltage levels for the analog and digital
circuitry contained within the PA Module.
The diagnostics, operation, and monitoring features of the PA Module are controlled by a
firmware driven microcontroller system.
The PA Modules are “Hot Swap” compatible. Defective PA Modules, accessible from the front of
the cabinet, may be removed and replaced while on-air, and without shutting the entire
transmitter system down.
NOTE: During this procedure an automatic power reduction will occur to ensure transmitter
protection.
Power Amplifier (PA) Module