Cessna 172SPHUSR05 Pilot Operating Handbook page 297

CESSNA
MODEL 1 72S
3. MARKER B EACON S ENSITIVITY LAM P AND TEST SWITCH
--The II MKR " Audio Select button m ust be pushed so that the
green ann unciator is illuminated for the marker beacon to
receive to provide an audio signal at beacon passage. When
this switch is on " H I SENS " (upper) position, the high
sensitivity is selected which permits you to hear the outer
marker tone about a mile out. At this poi nt you may select the
the " LO S E NS " (middle) position to temporarily silence the
tone. It wil l start to sound again when you are closer to the
marker, giving you a more precise i ndication of its location.
4. AUDIO SELECT BUTTONS -- Push button audio selection is
available for three Communications receivers ( IICOM
"COM
/1
and IINAV 2 "), the internal Marker Beacon receiver ( IIMKR"),
2
,
one DME, one ADF, and one additional auxiliary receiver
( "AUX "). The IIAUX " position could be used, for example, for
a second D M E or ADF. When a receiver's audio is selected,
the g reen annunciator illuminates at the bottom of the button .
Push the button again to deselect the receiver's audio.
5. M ICROPHONE SELECTOR SWITCH (M IC) -- Used to select
the desired transmitter for the cockpit microphones.
" C 1 " , "C2 " , and "C3" positions are for transmitting on the
Com Com 2, and Com 3 comm u nications transceivers,
respectively.
1,
bypass the KMA 26's audio amplifier and d irectly con nects
Com to the pilot's microphone and headphones.
provides a fail-safe method of comm un ication should the unit
1
fail . The " PA" position may be selected when the aircraft is
configured with a passenger address capability.
Com " feature always provides automatic headphone audio
selection to match the Com transmitter in use.
speaker audio, simply push the Speaker Select Switch (inner
right knob) to the "inll position . Pul l i ng the switch to the " out"
position removes speaker audio.
Figure Bendix/King KMA 26 Audio Selector Panel (Sheet 2 of 4)
1.
July 8/98
S UPPLEM E NT 3 - FAA APPROVED
and "COM 311), two Navigation receivers ( " NAV
The IIE M G " (emergency) position is used to
SECTION 9 - S U PP LEME NTS
11 ,
1
1"
The
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The " Auto
To add
S3-5