Installations - Cessna Skyhawk 172N 1980 Information Manual

CESSNA
MODEL
172N
SECTION
7
AIRPLANE & SYSTEMS DESCRIPTIONS
aware
that
if the sidetone volume level is set too high, audio
feedback
(squeal) may result when transmitting.
When the
airplane
has one
or two
transmitters, sidetone is
provided
in
both the speaker
and headset
anytime the
COM
AUTO selector switch is
utilized. Placing
the
COM
AUTO selector switch in the
OFF
position
will
eliminate
sidetone. Sidetone
internal adjustments
are
available
to the
pilot
through
the
front
of the audio
control panel
(see
figure
7-10).
Adjustment
can be made
by
removing the appropriate plug-button from the audio
control panel (left button for
headset adjustment and
right
button for
speaker adjustment),
inserting
a
small screwdriver into
the adiustment
potentiometer
and
rotating
it
clockwise to increase the
sidetone
volume
leve1.
When
the airplane has three transmitters,
sidetone
will
be
heard
on
either the speaker
or
a
headset
as
selected
with
the
AUTO
selector
switch.
Sidetone
may
be
eliminated by placing the AUTO selector switch in
the
OFF
position,
and
utilizing
the
individual
audio selector
switches' Adjust-
ment of speaker
and
headset sidetone
volume
can
only
be
accomplished
by
adjusting the sidetone potentiometers located inside the audio control
panel.
NOTE
Sidetone is not available
on
HF
Transceivers
(Types
PT10-
A
and ASB-125),
when installed.
M
ICROPHONE-HEADSET INSTALLATIONS
Three types
of
microphone-headset
installations are offered.
The
standard system provided
with avionics equipment includes
a
hand-held
microphone
and separate headset.
The
keying switch for this microphone
is on the microphone. Two
optional microphone-headset installations
are
also available;
these
feature a
single-unit microphone-headset combina-
tion which permits the
pilot to conduct radio communications without
interrupting other control operations to handle
a
hand-held microphone.
one microphone-headset combination is
offered
without
a
padded headset
and the other version has a padded
headset.
The microphone-headset
combinations
utilize
a
remote
keying switch
located on the
Ieft grip
of
the
pilot's control
wheel. The microphone and headset
jacks
are
located near
the
lower left corner
of the
instrument panel. Audio to aII three headsets
is
controlled
by the individual audio
selector switches and adjusted for
volume level by using the
selected
receiver volume controls.
1
July
1979
7-39