Motorola MSF 5000 Instruction Manual page 176

Chapter
4
Alignment
MSF
5000
Instruction Manual
Alignment Procedures
OPERATE
TRANSIT
RF TRAY COVER
TRANSIT
OPERATE
R409
LIO
R191
le
Ow
FO
FREQ, ADJ.
INJECTION FILTER
TUNING
SCREWS
MSFI018
021894JNM
Figure 4-6
Injection
Filter Tuning Screws
(RF
Tray Cover)
The
Preselector
Filter tuning
screws are accessed
through
the
RF
Tray
front panel.
There
are a
total of six Preselector
tuning screws,
except for
VHF
stations
which
contain only five tuning screws. For
VHF
stations, the
RF
Tray
front panel must
be
removed. The Preselector Filter tuning
screws
are
adjusted until the proper
reading is obtained on
the
metering panel.
The Image Filter tuning screws
are accessed from the top of the
RF
Tray
cover. The
Image Filter tuning screws
are
adjusted until the proper reading is obtained on
the
metering panel.
Typically,
the Preselector and Image Filter
require
only
a
fine adjustment.
However, if
the station requires
a
major tuning adjustment,
the coarse adjustment
must
be performed initially. Coarse adjustments
are
usually
required after
frequency changes, filter replacements, and servicing.
Coarse Adjustment
1.
If adjusting
a
VHF
station,
remove
the
RF
Tray front panel. Otherwise,
proceed to step
2.
2.
Using
the
Select/Set switch,
set the station to the
tuning
channel.
3.
Terminate the Preselector
by connecting
a
50
Q load
to the Preselector
input.
For non-duplex
repeaters and base stations, connect the load to the receive
antenna connection on the
Junction
Box.
4-10
68P81092E04
3/19/94
Chapter
4
Alignment
MSF
5000
Instruction Manual
Alignment Procedures
OPERATE
TRANSIT
RF TRAY COVER
TRANSIT
OPERATE
R409
LIO
R191
le
Ow
FO
FREQ, ADJ.
INJECTION FILTER
TUNING
SCREWS
MSFI018
021894JNM
Figure 4-6
Injection
Filter Tuning Screws
(RF
Tray Cover)
The
Preselector
Filter tuning
screws are accessed
through
the
RF
Tray
front panel.
There
are a
total of six Preselector
tuning screws,
except for
VHF
stations
which
contain only five tuning screws. For
VHF
stations, the
RF
Tray
front panel must
be
removed. The Preselector Filter tuning
screws
are
adjusted until the proper
reading is obtained on
the
metering panel.
The Image Filter tuning screws
are accessed from the top of the
RF
Tray
cover. The
Image Filter tuning screws
are
adjusted until the proper reading is obtained on
the
metering panel.
Typically,
the Preselector and Image Filter
require
only
a
fine adjustment.
However, if
the station requires
a
major tuning adjustment,
the coarse adjustment
must
be performed initially. Coarse adjustments
are
usually
required after
frequency changes, filter replacements, and servicing.
Coarse Adjustment
1.
If adjusting
a
VHF
station,
remove
the
RF
Tray front panel. Otherwise,
proceed to step
2.
2.
Using
the
Select/Set switch,
set the station to the
tuning
channel.
3.
Terminate the Preselector
by connecting
a
50
Q load
to the Preselector
input.
For non-duplex
repeaters and base stations, connect the load to the receive
antenna connection on the
Junction
Box.
4-10
68P81092E04
3/19/94