Axcera DT325B, Инструкция по эксплуатации

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350-Watt Digital VHF LB Transmitter Chapter 5, Detailed Alignment Procedures
DT325B, Rev. 0 5-1
Chapter 5
Detailed Alignment Procedures
5.1 System Preparation
This transmitter was aligned at the
factory and should not require additional
adjustments to achieve normal operation.
The Axciter takes the SMPTE 310 digital
stream input and converts it to the digital
IF output that connects to the
driver/amplifier chassis assembly. The
driver/amplifier converts it to the desired
VHF On Channel RF Output that is
amplified by the amplifier tray to produce
the systems output power level.
The Driver/Amplifier Chassis Assembly of
the transmitter is of a Modular design
and when a Module fails that module
needs to be changed out with a
replacement module. The failed module
can then be sent back to Axcera for
repair. Contact Axcera Customer Service
Department at 724-873-8100 or fax to
724-873-8105, before sending in any
module.
5.2 Module Replacement
Module replacement in the
Driver/Amplifier Chassis Assembly is a
relatively simple process. In the
Exciter/Driver assembly, the
Downconverter, Upconverter and
Control/Power Supply Module plug into
blind mating connectors located on the
Backplane board in the chassis. To
replace a module, refer to the following
procedure.
Loosen the two grip lock connectors,
located on the front panel, at the top
and bottom of the module,
counterclockwise until the module
releases. The Downconverter,
Upconverter, and Controller/Power
Supply can then be gently pulled from
the unit. After removal of the failed
module, slide the replacement module in
place and make certain it connects to
the backplane board. If the replacement
module does not slide in easily, verify it
is properly aligned in the nylon tracks,
located on both the top and bottom of
the module. After positioning, tighten
the two grip lock connectors.
Each Module has an assigned slot and
will not fit properly or operate in the
incorrect slot. Do not try to place a
Module in the wrong slot as this may
damage the slot or the connectors on
the backplane board. Each module has
the name of the module on the front,
bottom for identification and correct
placement. The Modules are placed in
the unit from left to right; (1) Axciter
Downconverter, (2) Blank panel, (3)
Blank Panel, (4) Axciter Upconverter, (5)
Controller/Power Supply and (6) Blank
panel.
5.3 (A3) VHF LB Amplifier Tray
(134363; Appendix D)
The Tray has been adjusted at the
factory to meet all specifications,
including Phase Adjustment to match the
multiple Trays in an Amplifier Array when
combined, and should not need adjusted
to attain normal operation. Any
adjustment of the Boards should be
accomplished in Manual Gain, S1 on (A5)
AGC Control Board (1306482) in Manual.
The Idling Currents for the amplifier
boards are adjusted with no RF Drive
applied. For Normal Operation, S1
should be in the Auto AGC position.
Connect a Dummy Load rated of at least
350 Watts to J2 the RF Output Jack of
the Tray.
5.3.1 (A13) AGC Control Board
(1306482; Appendix C)
Using a calibrated Wattmeter, check that
the Tray is operating at rated power.