Specifications

SECTION 9 - SUPPLEMENTS CESSNA
SUPPLEMENT 3 MODEL 172R NAV III
GFC 700 AFCS
U.S.
FAA APPROVED
GENERAL (Continued)
1. ANT/ADF MODE ANNUNCIATOR - Antenna (ANT) is selected
when the ADF button is in the OUT position. This mode
improves the audio reception and is usually used for station
identification. The bearing pointer is deactivated and will park in
the 90° relative position. Automatic Direction Finder (ADF) mode
is selected by pushing the ADF button. This mode activates the
bearing pointer and will point in the direction of the station
relative to the aircraft heading.
2. ACTIVE FREQUENCY DISPLAY - The frequency to which the
ADF is tuned is displayed here. The active ADF frequency can
be changed directly when either of the timer functions is
selected.
3. BFO (Beat Frequency Oscillator) ANNUNCIATOR - The BFO
mode is activated and annunciated by pushing the BFO button.
When BFO mode is active, the carrier wave and its morse code
identifier can be heard.
NOTE
CW signals (Morse Code) are unmodulated and no audio
will be heard without use of BFO. This type of signal is not
used in the United States air navigation. It is used in some
foreign countries and marine beacons.
4. STANDBY FREQUENCY/FLIGHT TIME OR ELAPSED TIME
DISPLAY - When FRQ is shown, the STANDBY frequency is
shown in the right display. The STANDBY frequency is selected
using the frequency select knobs. The selected STANDBY
frequency is put into the active frequency window by pushing the
frequency transfer button. Either the standby frequency, the
flight timer, or the elapsed time is shown in this position. The
flight timer and elapsed timer replace the standby frequency
which goes into blind memory to be called back at any time by
pushing the FRQ button. Flight time or elapsed time are shown
and annunciated by depressing the FLT/ET button.
5. FLIGHT TIMER AND ELAPSED TIMER MODE
ANNUNCIATION - Either the elapsed time (ET) or flight time
(FLT) mode is annunciated here.
(Continued Next Page)
172RPHBUS-S3-00
S3-6