User Manual

UHF Analog Driver/ Transm it ter Chapter 5, Detailed Alignm ent Procedures
LX Series, Rev. 0 5- 1
Cha pt er 5
Det ailed Alignm ent Procedur e s
This transm itter was aligned at the
factory and should not require additional
adjustm ents to achieve normal operation.
This transm itter takes the baseband
audio and video inputs or, if the
(Optional) 4.5- MHz com posite input kit is
purchased, either a single com posite
video + 4.5- MHz input or separate
baseband video and audio inputs, and
converts them to the desired UHF On
Channel RF Output at the system s output
power level.
The exciter/ am plifier of the LX Series
t ransm itter is of a Modular design and
when a Module fails that m odule needs to
be changed out with a replacement
module. The failed m odule can then be
sent back to Axcera for repair. Contact
Axcera Custom er Service Department at
724- 873- 8100 or fax to 724- 873- 8105,
before sending in any m odule.
5 .1 Module Re placem e nt
Module replacement on the LX series
products is a relatively sim ple process.
All modules plug directly into the
backplane board except for the power
am plifier m odule, and in higher power
units, the power supply and power
am plifier m odules, that plug into a blind
mating connector. 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 Modulator, I F Processor,
Upconverter and Controller/ Power
Supply can then be gently pulled from
the unit. There are two cables
connected to the rear of the Power
Am plifier Module in the exciter/ am plifier
chassis assem bly. These two cables
must first be removed before the PA
module will slide out.
After removal of the failed module, slide
the replacement m odule in place and
make certain it connects to the
backplane board. If the replacem ent
module is a PA Module replace the two
cables on the rear of the
exciter/ am plifier chassis assem bly. I f
the replacement m odule does not slide
in easily, verify it is properly aligned in
the nylon tracks, located on both the top
and bottom of the module.
N ote : Each Module has an assigned slot
and will not fit properly in the incorrect
slot. Do not try to place a Module in the
wrong slot as this may dam age the slot
or the connectors on the backplane
board.
Each module has the nam e of the
module on the front, bottom for
identification and correct placement.
The Modules are placed in the unit from
left to right; (1) Blank panel, (2)
Modulator (for analog transm itters) or a
Blank panel for a Translator or digital
transm itter, (3) I F Processor, (4)
Upconverter, (5) Controller/ Power
Supply and (6) Power Amplifier.
5 .1 .1 I n it ia l Test Se t Up
Check that the RF output at the coupler
is terminated into a dum m y load of at
least 100 watts. While performing the
alignment, refer to the Test Data Sheet
for the transmitter and compare the final
readings from the factory with the
readings on each of the m odules. The
readings should be very sim ilar. I f a
reading is way off, the problem is likely
to be in that m odule.
Switch On the main AC for the system .