AR 10044005, Руководство по эксплуатации и обслуживанию

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Model 5000A225A
42 Rev B
3.2.10 Output Combiner/Directional Coupler, Detector Assembly
The outputs from the amplifier modules in the MPA are combined into one output in the output combiner.
The combiner operates in a 180-degree configuration. The single output then passes through a dual directional
coupler, located internal to the combiner assembly, the output of which is routed to the main output connector
of the amplifier, a 1-5/8 EIA female connector. The forward and reflected ports of the directional coupler are
at a level of about –60 dB relative to the main output signal. The RF detectors for converting the amplifier’s
Forward and Reflected RF signals to usable DC signals are located in the driver/control unit. The detected
signals are used by the ALC, fault detection/control circuits and by the Forward and Reflected power display
on the Digital Control Panel (DCP).
Inside the detector assembly (Schematic 10025119), a combination of attenuators and MMIC amplifiers
process the signal to feed the output the sample signal to the front panel sample ports. Active detectors are
used to provide DC signals to the ALC board for amplifier control and also to provide the analog signal to the
control panel providing the power level readings on the display.
3.3 POWER SUPPLY
Refer to Interconnect Diagram Number 10044006 for low voltage units, and 10044007 for high voltage units.
Main power to the unit is supplied by three phase AC power within the proper range. In series with the line
voltage is the
Main circuit breaker, located on the rear panel. This circuit breaker supplies AC line voltage
to the power distribution box.. The driver/control unit and the main power amplifier unit are fed from outlets
in the power distribution box. The Driver/control unit and the MPA each have internal AC contactors. The
contactors are controlled by the front panel Power ON/Off switch and interrupted manually by the three-
position key-switch labeled
Inhibit – Local – Remote . The contactors feed AC directly to the primary inputs
of the main power supplies. When the main circuit breaker is on, AC power is fed to the low level/bias supply
PS1 in the driver/control unit. Therefore, when the circuit breaker is turned on, the control panel and basic
low-power supplies are alive, and the amplifier is armed for Power On. At this time, the front panel display is
illuminated and the control circuitry is active.
3.4 CONTROL CIRCUITS
3.4.1 Fiber-Optic System Control Link
The 5000A225A control system uses a fiber-optic communication system to link each of the MPA’s back to
the Driver/Controller unit. The Digital Control Panel (DCP) uses this link to send information to the system
MPA’s and read fault conditions. Therefore, this link is critical to the operation of the amplifier system.
When the system is powered up, the DCP goes through an addressing process in which a communication link
is established for each item in the serial chain. If this process fails, a fault condition is generated.
An LED is installed on the rear of each MPA to indicate the state of this link. See Table 3-1 below for the
link states. This information is also indicated on a label next to the LED.
Table 3-1. Link States
LED F/O LINK
OFF NONE
BLINK LOCAL
ON SYSTEM