Service manual

0
If
you
don't
use
Belden
cable,
use
a
cable
(such
as
BELDEN
8723).
similar
type,
with
wire
gauges
and
capacitance
as
specified
in
this
manual.
Seldom
will
an
MS-400A
be the
only
four-
The
conductors
in
the
cable,
especially
channel
station
in
the
system;
therefore
In
longer
runs
(over
500
feet)
must
have
it
is often
convenient
to
use
multi-pair
low
DC
resistance
(less
than
15
ohms
per
shielded
cable
for
at
least
some
of the
1000
feet;
large
diameter
conductors)
system
wiring.
and
low
capacitance
(less
than
or
equal
to
55
pF per
foot
of
cable--capacitance
Crosstalk
between
conductor
and
shield).
When
multiple
channels
are
fed
to
remote
stations,
the
amount
of crosstalk
is
----------------------------------------
proportional
to
the amount
of DC
Refer
to
the
Belden
wire
specs
on
page
6
resistance
in
the
ground
return.
Two
to
ensure
that
your
substitute
cable
is
ohms
or
less
resistance
is
ideal;
two
comparable.
ohms
will
give
you
40
dB
of
isolation.
----------------------------------------
Anything
greater
than
two ohms
will
increase
crosstalk.
Each
channel
must
MULTI-CHANNEL
CABLE
CONSIDERATIONS
be
fed
in
its
own
separate
shield.
When
installing
a
system
that
includes
multi-channel
stations,
the
channel
When
connecting
four-pair
cable
between
feeds
may
be routed
individually
to each
multi-channel
stations,
all
the
shields
station
with
separate
two-conductor
and
ground
wires
should
be
connected,
shielded
cables
OR
four
channel
feeds
effectively
lowering
ground
resistance
may
be
routed
together
with
one
four-
and
reducing
crosstalk.
Refer
to
the
pair
shielded
cable
(such
as
BELDEN
diagram
on
pages
6 &
9. Also,
tie
unused
8725;
see multi-channel
cable
connection
wires
in
your
interconnect
cable
to
diagram
on
page
6).
Two
channel
feeds
ground
(Pin
1),
thereby
further
reducing
may
be
routed
with
a two-pair
shielded
crosstalk.