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DESCRIPTION
The
Vehicular
Repeater
System
consists
of
the
MASTR
Executive
II
Vehicular
Repeater
Radio,
a Mobile
Radio,
Control
Unit,
a
MASTR Personal
Series
(PE)
Portable
Radio
Unit
with
its
associated
Vehicular
Charger
Unit
and
associated
power/control
cables
(See
Figure
2).
The Vehicular
Repeater
System
retransmits
portable-to-base
and base-to-
portable
transmissions
to
an
operator,
using
the
PE
radio,
away
from
his
vehicle.
MASTRe
Executive
II
Vehicular
Repeater
Radio
Combinations
are
compact,
highly
reliable
and ruggedly-constructed
units
that
are
designed
to meet the most
stringent
requirements
in
the
two-way
radio
field.
The
vehicular
repeater
radio
unit
operates
in conjunction
with
a
MASTR II,
MASTR Executive
II,
DELTA S/SE
or RANGR mobile
radio.
The radios
are
fully
transistorized
--
utilizing
both
discrete
components
and
integrated
circuits
(.IC'~s)
for
highest
reliability.
The standard
combination
is
equipped
with
the
following:
l
Plug-in
oscillator
modules
for
tO.O005% oscillator
stability.
e
Channel
Guard
(tone
squelch)
decode.
l
Type 90 tone
encode
and decode.
The
combination
is
contained
in
a
"slide-rail",
tamper
resistant
mounting
frame
and
is
designed
for
trunk-mount
installations.
When unlocked,
the
unit
can be easily
pulled
out of its
frame
for
servicing.
The Vehicular
Repeater
is
of modular
construction
and the
modules
may be used
interchangeably
in
vehicular
repeater
combinations,
except
for
strapping
arrangements
required
for
operation
in
your
radio.
No
modifications
are
required
when
transferring
the
modules
from
one vehicular
repeater
to
another.
All
major
modules
and tuning
adjustments
except
for
the
system
board,
Channel
Guard and Type 90 tone
modules
are easily
accessible
from the top of the radio
(See
Figure
1).
Centralized
metering
jacks
for
the
transmitter
and receiver
are provided
for
simplified
alignment
and troubleshooting.
Test
points
are
available
on the
system
board.
TRANSMITTER
The
transmitter
consists
of
an
exciter
board
and
a power
amplifier/
antenna
switch
assembly.
The PA/antenna
switch
assembly
mounts
on a hinged
heat
sink
casting
that
swings
down
for
easy
access.
A low-pass
filter
mounts
on the
heat
sink
next
to the PA assembly.
RECEIVER
The
receiver
consists
of
an
oscillator/multipIier
assembly
(Osc/
Mult),
RF assembly,
Mixer/IF
assembly
(MIF)
and IF-Detector
assembly
(IF-Det.).
The audio
and squelch
circuitry
for
the
receiver
is
located
on the system
board.
SYSTEM BOARD
The
system
board
contains
the
10
Volt
regulator,
frequency
select
inter-
face,
mobile
squelch,
repeater
squelch,
mobile
microphone
interface,
Type
90
interface,
repeater
CG interface
and
logic
board
interface
circuit.
The board
is
mounted
on the
underside
of
the
radio
chassis.
The system
board
contains
test
points
to monitor
operation
of the
trans-
mitter,
receiver
and logic
boards.
LOGIC BOARD
The
logic
board
contains
a micro-
computer
which
establishes
repeater
priority
and controls
all
radio
transmi-
ssions
between
the portables
and the base
station.
It
also
provides
the
carrier
control
timer
function,
courtesy
beep,
and
multiple
priority
clearing.
The
board
is
mounted
on the
underside
of
the
radio
chassis
and plugs
into
the
system
board.
MOBILE DETECTOR (Optional)
The Mobile
Detector
is
used
in
dup-
lex
radio
systems
and is
mounted
next
to
the vehicular
repeater
receiver.
It
mon-
itors
the mobile
radio
transmit
frequency
to
determine
if
another
repeater
is
re-
peating
portable-to-base
transmissions.
If
there
is
a portable-to-base
transmis-
sion
in
progress,
it
causes
the
logic
board
to maintain
a non-priority
status.
VEHICULAR REPEATER SYSTEM DESCRIPTION
The
vehicular
repeater
radio
con-
tains
the
control
and
logic
circuits
necessary
to
transform
a vehicle
into
a
mobile
repeating
station.
A typical
mo-
bile
installation
is
shown
in
Figure
3.
The vehicular
repeater
is
a single
fre-
quency
radio
operating
in the
138-174
MHz
or
406-512
MHz frequency
range
with
a
low-power
(300
milliwatts)
transmitter.
The
flexible
spring
antenna
for
the
vehicular
repeater
is normally
located
on
the
trunk
area of the vehicle.
1
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