User Manual
ADCP-75-150 • Preliminary Issue A • March 2003 • Section 4: Operation
Page 4-13
©
2003,
ADC
Telecommunications,
Inc.
4. Place
the
RF
ON/OFF
switch
on
the
LPA
in
the
ON
position.
5. If
using
a
spectrum
analyzer,
proceed
to
step
6.
If
using
a
power
meter,
measure
the
composite
signal
power
from
the
STM
and
then
proceed
to
step
8.
6. Measure
the
RF
level
of
a
single
carrier,
such
as
the
control
channel,
in
dBm.
Make
sure
the
resolution
bandwidth
of
the
spectrum
analyzer
is
30
kHz.
7. Calculate
the
total
composite
signal
power
using
the
following
formula:
P
tot
=
P
c
+
10Log
N
–
(see
Note)
Where,
P
tot
is
the
total
composite
power
in
dBm
P
c
is
the
power
per
carrier
in
dBm
as
measured
in
step
6,
and
N
is
the
total
number
of
channels.
8. Record
the
result
measured
in
step
5
or
calculated
in
step
7.
9. Place
the
MUTE/NORM/RESET
switch
on
the
LPA
in
the
OFF
position.
10. Disconnect
the
spectrum
analyzer
or
RF
power
meter
from
the
STM
ANTENNA
port.
11. Re-connect
the
antenna
cable
to
the
STM
ANTENNA
port.
2.7 Enter Remote Forward Attenuation
The
STM
internal
forward
path
attenuator
setting
is
used
to
reduce
the
power
level
of
the
composite
output
signal
level
at
the
STM
antenna
port.
The
maximum
composite
output
signal
level
at
the
STM
antenna
port
is
set
using
the
Host
internal
forward
attenuator
(see
Section
2.4).
However,
component
variations
may
result
in
the
output
power
at
the
STM
antenna
port
being
slightly
above
or
below
the
required
power
per
channel.
If
this
is
the
case,
the
STM
forward
attenuator
may
be
used
in
conjunction
with
the
Host
forward
attenuator
to
add
or
remove
attenuation
to
produce
the
required
output
signal
level.
If
less
power
is
required,
the
STM
forward
attenuator
may
be
used
to
reduce
the
power
level.
The
default
setting
is
0
dB.
Use
the
following
procedure
to
change
the
STM
forward
attenuation:
1. Click
on
the
REMOTE
LPA
tab.
The
REMOTE
LPA
display
will
open
within
the
DEMS
main
window
as
shown
in
Figure 4-10.
Note:
If
calculating
the
composite
power
for
a
CDMA
system,
reduce
the
initial
result
by
16.23
dBm
Note:
To
comply
with
Maximum
Permissible
Exposure
(MPE)
requirements,
the
maximum
composite
output
from
the
antenna
cannot
exceed
1000
Watts
EIRP
and
the
antenna
must
be
permanently
installed
in
a
fixed
location
that
provides
at
least
6
meters
(20
feet)
of
separation
from
all
persons.