Cessna Skyhawk 172N Pilot Operating Handbook page 143

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CESSNA SECTION 7
MODEL 172N
AIRPLANE
&
SYSTEMS DESCRIPTIONS
selected with the AUTO selector switch. Sidetone may be
eliminated by placing the AUTO selector switch in the OFF
position. and utilizing the individual radio selector
switches. Adjustment of speaker sidetone volume is
accomplished by adjusting the sidetone potentiometer
located inside the audio control panel. During adjustment,
be aware that if the sidetone level is set too high it can
cause audio' feedback (squeal) when transmitting. Head ­
phone sidetone level adjustment to accommodate the use
of the different type headsets is accomplished by adjusting
potentiometers in the N A V f COM radios.
AUDIO SELECTOR SWITCHES
The audio selector switches, labeled NAV ICOM 1,2 and 3 and ADF 1
and 2, allow the pilot to initially pre-tune all NAVf COM and ADF
receivers, and then individually select and listen to any receiver or
combination of receivers. To listen to a specific receiver, first check that
the AUTO selector switch is in the OFF (center) position, then place the
audio selector switch corresponding to that receiver in either the SPEAK­
ER (up) or PHONE (down) position. To turn off the audio of the selected
receiver, place that switch in the OFF (center) position.
If
desired. the audio
selector switches can be positioned to permit the pilot to listen to one
receiver on a headset while the passengers listen to another receiver on the
airplane speaker.
The ADF 1 and 2 switches may be used anytime ADF audio is desired.
If
the pilot wants only ADF audio. for station identification or other reasons,
the AUTO selector switch
(if
in use) and all other audio selector switches
should be in the OFF position.
If
simultaneous ADF and NAVf COM audio
is acceptable to the pilot, no change in the existing switch positions is
required. Place the ADF 1 or 2 switch in either the SPEAKER or PHONE
position and adjust radio volume as desired.
NOTE
If
the N A V I 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.
MICROPHONE-HEADSET INSTALLATIONS
Three types of microphone-headset installations are offered. The
1 July 1978
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