A/C Power, Rf Input And Communication Plug-In - Hitachi E-Compact High Power Series Operation Manual

The Power Amplifier Drawer MOD GV 40272/40276 uses eight RF amplifier pallets operating in
parallel. The chassis is configured with four pallets per side (top & bottom). Each pallet incorporates the
Ampleon BLF-888E Broadband Doherty LDMOS device. Doherty amplifiers significantly improve efficiency
by passing the signal peaks in the class C device while using the class AB device to handle average
power.
The 888E device internally has two parallel transistors in a Doherty configuration; one half of the
device is operating in class AB and the other in class C. Furthermore, the 888E device is designed to be
an asymmetric Doherty amplifier, with higher peak power capability on the Class C for better linear
performance and higher peak power capability.
Amplifier pallets are housed in a 3RU rack mounted chassis. The chassis is self-contained and
includes RF pallets, removable AC to 50VDC power supply, control and monitoring logic, low level RF
splitting, high level RF combiner, as well as the cooling fans. The pallets are mounted to oversized
extruded aluminum heat sinks for cool operation in the harshest conditions.
The Power Amplifier Drawer is controlled by the CM9001 Control Module. The CM8001 monitors,
manages and controls all the drawer parameters via the RS485 interface called MODBUS.
Each final power amplifier module has protection systems for high temperature and over-current.
The final power amplifier assembly has a protection system for excessive VSWR conditions. The amplifier
chassis provides at a glance front panel indicators. LED's to indicate the status of the PS voltage and
current, pallets, temperature status, as well as a general amp status indicator. All of the amplifier status
information is collected via an amplifier interface board. The interface board provides its status back to the
transmitter controller for system level control and monitoring.

3.2.4. A/C Power, RF Input and Communication Plug-In

A1 AC POWER PHASE 1 – PS1
A2 AC POWER PHASE 2 – PS2
A3 GND
B1 AC POWER PHASE 2 – PS2
B2 AC POWER PHASE 2 – PS1
B3 GND
C1 RF INPUT
C2 RF SAMPLE
A B C
E-Compact HP-BB3 Series
D
D1 Pinout Configuration – Address A2
D2 Pinout Configuration – Address A3
D3 RS485A
D4 N/A
D5 Reflected Power
D6 Pinout Configuration – Address A1
D7 GND
D8 GND
D9 N/A
D10 GND
D11 Pinout Configuration – Address A0
D12 N/A
D13 RS485B
D14 N/A
D15 Forward Power
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