POWER
AMPLIFIER
LOW
BAND
PUB96
‐
28
Rev
2
Aug.
2007
28-5
PA
Module,
•
Figure
1
Module
sweep
Setup
Green
LED
Sensitivity
Adjustment
One
of
the
functions
of
the
VSWR
board
is
to
monitor
the
overall
gain
of
the
PA
module.
This
VSWR
board
is
located
at
the
rear
of
the
module,
adjacent
to
the
output
RF
connector.
For
the
locations
of
the
components
on
the
board,
please
refer
to
Figure
7.
Verify
that
all
the
PA
modules
are
in
good
working
order,
and
then
proceed
as
follows:
•
With
all
modules
running
at
normal
operating
power,
place
AGC/MANUAL
switch
into
the
MANUAL
position
and
adjust
the
exciter
output
power
until
the
transmitter
output
power
reads
110%.
•
Remove
the
module
to
be
set
up,
and
remove
the
two
front
fuses
from
it,
in
order
to
simulate
a
single
FET
package
failure.
Replace
this
"crippled"
module
in
the
transmitter,
and
apply
a
nominal
50%
APL
staircase
video
signal
to
the
transmitter
(analog
transmitters).
•
The
green
LED
should
now
be
extinguished;
if
it
is
not,
remove
the
module
and
adjust
potentiometer
(R4)
on
the
VSWR
board
clockwise,
replace
the
module
and
try
again,
repeating
until
the
LED
is
barely
extinguished
when
the
module
is
re
‐
powered.
•
Replace
the
fuses
so
the
module
is
again
fully
operational,
and
verify
that
the
green
LED
is
now
fully
lighted
when
the
module
is
replaced
in
the
transmitter
and
re
‐
powered.
