Motorola MSF 5000 Instruction Manual page 188

Chapter4
Alignment
MSF
5000
Instruction Manual
Alignment Procedures
OPERATE
TRANSIT
TRANSIT
D
OPERATE
©
CUTBACK CONTROL
POTENTIOMETER
Lid
R453
ut Rig
FREGADJ.
R358
@
FO
4-22
RF TRAY COVER
MSFI036
021894JNM
Figure 4-13
Cutback Control Adjustment
For
900
MHz
Analog Plus stations, an
High
Stability Oscillator (HSO)
or an external
reference is required. For all other bands, an
HSO
or an external reference is not
required, but optional.
The Fo Freq
Adj
potentiometer is located on the Uniboard. For
VHF
stations,
the
Fo Freq
Adj
is accessed from the top of the
RF
Tray
cover.
For all
other bands, the
Fo Freq
Adj
is accessed from the
RF
Tray
front panel.
NOTE
A
minimum warmup time
of
60
minutes is required
if
the station is
a 900
MHz
Analog Plus
station
or
if
it is
equipped
with
a
High Stability Oscillator
Option
(C573).
Otherwise,
ensure that the frequency reference device
is
fully
warmed
up.
1.
On
900
MHz
Trunking
stations or stations
equipped
with
the External
Reference
Option
(C574),
apply
the site
high stability
5
MHz
reference
signal
to the external reference connector on the
Junction
Box.
2.
Adjust
U1 on the reference synthesizer board for
1.5
+/-
0.1
Volts
at
TP1.
3.
Set the
Acc Dis/Reset switch
to
Acc Dis.
4.
If necessary, attenuate the transmitted
RF
signal from the station to the
frequency measuring device.
68P81092E04 3/19/94
Chapter4
Alignment
MSF
5000
Instruction Manual
Alignment Procedures
OPERATE
TRANSIT
TRANSIT
D
OPERATE
©
CUTBACK CONTROL
POTENTIOMETER
Lid
R453
ut Rig
FREGADJ.
R358
@
FO
4-22
RF TRAY COVER
MSFI036
021894JNM
Figure 4-13
Cutback Control Adjustment
For
900
MHz
Analog Plus stations, an
High
Stability Oscillator (HSO)
or an external
reference is required. For all other bands, an
HSO
or an external reference is not
required, but optional.
The Fo Freq
Adj
potentiometer is located on the Uniboard. For
VHF
stations,
the
Fo Freq
Adj
is accessed from the top of the
RF
Tray
cover.
For all
other bands, the
Fo Freq
Adj
is accessed from the
RF
Tray
front panel.
NOTE
A
minimum warmup time
of
60
minutes is required
if
the station is
a 900
MHz
Analog Plus
station
or
if
it is
equipped
with
a
High Stability Oscillator
Option
(C573).
Otherwise,
ensure that the frequency reference device
is
fully
warmed
up.
1.
On
900
MHz
Trunking
stations or stations
equipped
with
the External
Reference
Option
(C574),
apply
the site
high stability
5
MHz
reference
signal
to the external reference connector on the
Junction
Box.
2.
Adjust
U1 on the reference synthesizer board for
1.5
+/-
0.1
Volts
at
TP1.
3.
Set the
Acc Dis/Reset switch
to
Acc Dis.
4.
If necessary, attenuate the transmitted
RF
signal from the station to the
frequency measuring device.
68P81092E04 3/19/94