Auto Audio Selector - Cessna Skyhawk 172N 1980 Information Manual

SECTION
7
AIRPLANE & SYSTEMS DESCRIPTIONS
CESSNA
MODEL
172N
PHONE
position (or vice versa) is not normally
recom-
mended as
it will
cause audio
from both communications
receivers
(and
any other
navigation receiver with its audio
selector switch in
the
PHONE
position)
to
be
heard
on
both
the airplane speaker
and
the
headset simultaneously.
AUTO AUDIO SELECTOR SWITCH
The audio control panel
used
with
three transmitters incorporates
a
three-position toggle switch,
labeted AUTO, which
is
provided
to
automat-
ically
match the audio of the
appropriate NAV/COM receiver to
the
selected
transmitter.
To
utilize this automatic
feature, leave all NAV/
COM
audio selector switches in
the center (OFF) position,
and
place the AUTO
selector switch
in
either the SPEAKER or PHONE position,
as desired.
Once the AUTO
selector
switch
is
positioned,
the
pilot
may then
select any
transmitter
and
its
associated
NAV/COM receiver audio simultaneously
with
the
transmitter
selector switch.
If
automatic audio selection is not
desired, the AUTO selector switch should
be
placed in the
center (OFF)
position.
NOTE
If
the NAV/COM audio selector switch corresponding
to
the
selected
transmitter is in
the
PHONE position with
the
AUTO
selector switch in the SPEAKER position, all
audio
selector switches placed in the
PHONE position will
automatically
be connected
to both the airplane
speaker
and
any
headsets
in
use.
ANNUNCIATOR LIGHTS
BRTGHTNESS
AND
TEST SWITCH
The audio control panel used with
either
one
or two
transmitters
incorporates
a
three-position toggle-type switch
to
control
the brightness
level
of
the
marker
beacon
indicator lights
(and certain other annunciator
Iights
associated
with
avionics equipment).
When
the
switch is
placed
in
the center (DAY) position,
the
indicator lights will
show
full
bright.
When
this
switch is
placed
in
the up (NITE) position, the Iights are set to
a
reduced level for typical night operations
and can be further
adjusted
using the RADIO LT dimming rheostat knob.
The down (TEST)
position
illuminates all Iamps
(except
the
ARC
Iight in
the
NAV indicators) which
are controlled by the switch to the full
bright
level
to
verify
lamp opera-
tion.
SIDETONE OPERATION
Cessna
radios are equipped with
sidetone
capability (monitoring
of
the
operator's own voice transmission). While adjusting sidetone,
be
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1
July
1979