Service manual

e|
IV.
PARTS
LISTING
Part
#
Description
Qty.
Schematic
Reference
Desig.
710133
KB-112
PC
Module
Assembly
I
250156
Front
Panel
I
500089
Speaker,
3"
round,
16
ohm
I
SPi
250054
Speaker
screen,
3"
470037
Trimpot
(volume)
1
P1
500056
Mic,
electret
1
Ml
640005
Mic
bushing
640027
Rubber
mount
for
mic
390000
Lamp,
amber
1
11
390007
Red
LED
1
12
510028
Switch,
momentary
push
2
S1,
S2
240020
Switch
cover,
red
(1)
240021
Switch
cover,
black
(1)
280067
Dress
cone
nut
(2)
210085
Terminal
Strip,
5-screw
I
TBI
210086
Header
(5)
250178
Terminal
Strip
label
1
250193
Dip
Switch
label
1
210002
Intercom
Input,
D3M
1
31
(P
Box)
210003
Intercom
Output,
D3F
1
J2
(P
Box)
240003
Handle
I
P
Box
240010
Rubber
foot,
1/2"
square
8
P
Box
810027
Instruction
Manual
1
V.
THEORY
OF
REMOTE
STATION
OPERATION
Refer
to
the
KB-112
Schematic
(last
dB
loss
in
audio
level.
page)
when
reading
this
section
for
a
clearer
understanding
of
what
The
KB-112
is
a
"half-duplex"
de-
occurs
during
KB-112
operation.
vice,
which
means
that
its
operator
cannot
simultaneously
talk
and
lis-
The
KB-112
incorporates
Clear-Com's
ten;
only
one
action
may
occur
at
a
high-impedance
bridging
method,
so
time.
it
connects
to
the
intercom
line
without
taking
appreciable
power
During
"normal"
operation,
the
from
the
line.
This
enables
up
to
speaker
remains
on
and
the
mic
off.
20
Stations
to
be
connected
on
one
The
Push-To-Talk
button
(Sl
in
the
line
extending
from
the
Main
Sta-
Schematic)
shuts
off
the
speaker
tion
or
Power
Supply,
with
only
a
6
and
turns
on
the
mic;
this
button
7