12 |
P a ge
BDA
OPERATION
ALC
(Automatic
Level
Control)
To
minimize
intermodulation
products,
each
amplifier
in
the
BDA
contains
an
ALC
feedback
loop.
The
ALC
circuit
senses
the
output
power
and
limits
it
to
the
factory
preset
level
as
specified
on
each
product
specification.
Each
amplifier
in
the
BDA
contains
an
ALC
feedback
loop.
The
ALC
circuit
senses
the
output
power
and
limits
it
to
the
factory
preset
level.
A
red
indicator
lamp
is
located
on
the
interior
panel
of
the
BDA
and
illuminates
when
the
output
power
exceeds
the
ALC
set
point.
To
establish
proper
operating
gain
on
the
Uplink
and
Downlink
paths,
start
with
the
Downlink.
Observe
the
red
indicator
lamp
on
the
Uplink
amplifier.
Units
are
shipped
with
maximum
attenuation.
Decrease
attenuation
one
step
at
a
time
until
the
[DOWNLINK
ALC]
led
is
lit.
Then,
using
the
Downlink
step
attenuator,
increase
the
attenuation
until
the
LED
turns
off.
Repeat
the
process
for
the
Uplink.
The
level
indicator
is
accurate
to
+/
‐
0.4
dB
of
the
ALC
set
point.
If
a
test
radio
is
unavailable
during
commissioning
to
test
the
actual
Uplink
power,
a
safe
rule
of
thumb
on
Uplink
adjustment
is
to
set
the
gain
10
dB
lower
than
the
Downlink
path.
Operation
of
the
BDA
at
maximum
gain
with
greater
than
‐
30
dBm
average
power
incident
on
either
BASE
or
MOBILE
port
can
cause
damage
to
the
BDA.
Figure
2a
Conditions
for
ALC
Alarm
The
alarm
monitors
current
of
both
uplink
and
downlink
amplifiers.
An
alarm
condition
will
occur
if
either
uplink
or
downlink
amplifiers
are
over
its
current
tolerance/
ALC
limitation.
Conditions
for
Uplink/Downlink
Alarm
These
alarms
monitor
the
status
of
the
corresponding
amplifier
path.
If
either
of
these
LEDs
are
on,
and
no
other
alarm
LED
are,
this
is
an
indication
of
amplifier
failure,
please
contact
G
‐
Wave
for
an
RMA.
Conditions
for
Donor
Alarm
The
alarm
monitors
the
connection
of
the
BDA
to
the
donor
antenna.
An
alarm
condition
will
occur
if
there
is
a
disconnect
at
the
donor
antenna.
Donor
LED,
UL/DL
Amplifier
LED
will
indicate
and
all
amplifiers
will
shut
down.
Conditions
for
Mobile
Alarm
The
alarm
monitors
mobile
antenna
conditions
to
the
VSWR.
In
the
event
a
mobile
antenna
fails,
this
will
generate
reflected
power
to
the
amplifier.
Mobile
Alarm
and
Amplifier
UL
will
indicate.
