21
CLEAR COM
JUMPER OPTIONS
Name
Description
Procedure
Default Setting
Intercom pre-
fader
Makes talk level
independent of
R1741.
JP1704, cut trace
between pins 2
and 3, jumper
pins 1 and 2.
Post fader.
Modify talk level
Use with pre-
fader mod
JP1803, cut
jumper between
pins 2 and 3,
install resistor
voltage divider
across pins 1, 2,
and 3. Keep total
value below 10k
bypassed
Change sidetone
level (rev A and
later)
Use to raise or
lower sidetone
level
using a resistor,
bridge
E1804/E1805 to
lower, bridge
E1805/E1806 to
raise it. Try 4k7 for
starters. See
schematic.
Not present.
Normal sidetone
cancellation is
about 10 dB.
More
cancellation than
this is highly
dependent on
the intercom line
and its loading
conditions.
Listen when
called
Bypasses ignore
switch when call
signal detected
locate JP1801,
cut trace
between pins 2
and 3, jumper
pins 1 and 2.
Enabled. (call
signal bypasses
ignore switch).
Talk when called
Enables
microphone
when call signal
detected
Locate JP1802,
install jumper.
Disabled. Could
cause trouble in
high-noise
environments.
Lamp Kill (rev A
and later)
Flashes console
lamps when call
signal detected
Locate JP1804,
install jumper.
Disabled.
