Harris DiamondCD Series, Техническое руководство

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3/6/08 888-2463-001 1-11
WARNING: Disconnect primary power prior to servicing.
Section 1 Introduction
Diamond Series™
1.2.5.1 PA Modules
The Power Amplifier modules use LDMOS FETs for amplification. See Figure 1-7. The
amplifiers use a palletized approach to provide a means of module repair at the pallet
level. Six output pallets provide up to 600 watts RMS DTV power, a seventh pallet is
used as a driver for the output pallets. Modules are self protecting, using an on-board
module controller and on/off solid state relay to facilitate fast shut down if a fault
occurs. All module faults are communicated to the Cabinet Controller via the CAN
serial bus. Module on/off control is via the serial interface and a separate parallel
control. The modules are hot pluggable to allow on-air maintenance and repair.
Modules include temperature compensation and AGC to control gain stability over the
ambient temperature range of the transmitter.
Each PA module has a pair of touch switches behind the front facade, one on each end
(left and right side). When the edges of the module are grasped to pull the module out,
the touch switches are activated, shutting the module off before it is disconnected.
Figure 1-7 PA Module Block Diagram
AB
PHASE
&
GAIN
CONTROL
BOARD
SS RELAY
AB
AB
AB
AB
AB
AB A
LDMOS FAULT
FWD
TEMP
Pin
+32V
BIAS
RF IN
TO MAIN CONTROLLER
SWITCHED
+32V
ON/OFF
MODULE ENABLE
DC
SHORT
32V
MON
RF
OUT