Bruker BLAH500 E, Operating & Service Manual

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Operating & Service Manual Version 002 BRUKER BIOSPIN 19 (51)
5
Technical
Description 5
System Overview 5.1
The BLAH500 E Amplifier 700-900MHz provides :
•
A RF Output of 500W and more on the Solid Output H500, over the full
frequency range 650 to 900MHz, when selected for Solid operation with
SEL H500/H50 command controlled at TTL level low.
•
A RF Output of 50W and more on the High Resolution Output H50, over the
full frequency range 650 to 900MHz, when selected for High Resolution
operation with SEL H500/H50 command controlled at TTL level High.
The RF section of the system consists of an embedded router fixed on the front
panel and a linear module BLMH500/H50-E mounted around a single self-
contained Push fan assembly heatsink.
The embedded router has three RF inputs and one RF output feeded to the driver
amplifier located on the BLMH500/50-E module.
A linear class A / AB driver using switches and bias voltage gatings, delivers the
RF input power to the Power Amplifier. This driver is located on the top of the
heatsink assembly.
The class AB power amplifier is located on the bottom of the heatsink assembly.
The output of the power amplifier is connected to a bi-directional high dynamic
coupler mounted on the front panel of the amplifier. This output will be the Solid
H500 output when the amplifier is controlled for Solid applications.
When controlled for High Resolution applications, the output of the driver is
switched to the front panel H50 output via a RF relay and a bi-directional high
dynamic coupler.
The entire system is controlled by a Digital Signal Processing control board,
processing information from the amplifier and blanking signal, providing protection
from excessive peak power, duty cycle and pulse width for average power,
maximum reflected power and heatsink over-temperature.
The DSP control board reads the indentification information of the amplifier (BIS).
Monitoring of fan status, supply status and LED's status is also performed by the
control board.
Circuits such as BLAC6 Extension Board 1 Channel and Status LED's board,
complete the amplifier assembly.