Cessna 1980 172RG Cutlass Pilot Operating Handbook page 130

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CESSNA 300 NAV/COM
(TYPE RT-385A)
1. COMMUNICATION OPERATING FREQUENCY READOUT (Third-decimal-
place is shown by the position of the "5-0" switch).
2. 5-0 SWITCH - Part of Com Receiver-Transmitter Fractional MHz Frequency
Selector. In "5" position, enables Corn frequency readout to display and C o m
Fractional MHz Selector to select frequency in .05-MHz steps between .025 and
.975 MHz. In "0" position, enables COM frequency readout to display and Com
Fractional MHz Selector to select frequency in .05-MHz steps between .000 and
.950 MHz.
The "5" or "0" may be read as the third decimal digit, which is not
displayed in the Com fractional frequency display.
Figure 1. Cessna 300 Nav/Com (Type RT-385A), Operating Controls
and Indicators (Sheet 1 of 3)
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PILOT'S OPERATING HANDBOOK
SUPPLEMENT
NOTE
1 July 1979
PILOT'S OPERATING HANDBOOK
SUPPLEMENT
3. NAVIGATION OPERATING FREQUENCY READOUT.
4. ID-VOX-T SWITCH - With VOR or LOC station selected, in ID position, station
identifier signal is audible; in VOX (Voice) position, identifier signal is sup-
pressed; in T (Momentary On) position, the VOR navigational self-test function is
selected.
5. NAVIGATION RECEIVER FRACTIONAL MEGAHERTZ SELECTOR - Selects
Nav frequency in .05-MHz steps between .00 and .95 MHz; simultaneously selects
paired glide slope frequency and DME channel.
6. NAV VOL CONTROL - Adjusts volume of navigation receiver audio.
7. NAVIGATION RECEIVER MEGAHERTZ SELECTOR - Selects NAV frequency
in 1-MHz steps between 108 and 117 MHz; simultaneously selects paired glide
slope frequency and DME channel.
8. COMMUNICATION RECEIVER-TRANSMITTER FRACTIONAL MEGAHERTZ
SELECTOR - Depending on position of 5-0 switch, selects COM frequency in .05-
MHz steps between .000 and .975 MHz. The 5-0 switch identifies the last digit as
either 5 or O.
SQUELCH CONTROL - Used to adjust signal threshold necessary to activate
9.
COM receiver audio. Clockwise rotation increases background noise (decreases
squelch action); counterclockwise rotation decreases background noise.
10. COMMUNICATION RECEIVER-TRANSMITTER MEGAHERTZ SELECTOR -
Selects COM frequency in 1-MHz steps between 118 and 135 MHz.
11. COM OFF-VOL CONTROL - Combination on/off switch and volume control;
turns on NAV/COM set and controls volume of communications receiver audio.
12. BC LAMP - Amber light illuminates when an autopilot's back-course (reverse
sense) function is engaged; indicates course deviation pointer is reversed on
selected receiver when tuned to a localizer frequency. Light dimming is only
available when installed with an audio control panel incorporating the annuncia-
tor lights DAY/NITE selector switch.
13. COURSE INDEX - Indicates selected VOR course.
14. COURSE DEVIATION POINTER - Indicates course deviation from selected
omni course or localizer centerline.
15. GLIDE SLOPE "GS" FLAG - When visible, red GS flag indicates unreliable glide
slope signal or improperly operating equipment. Flag disappears when a reliable
glide slope signal is being received.
16. GLIDE SLOPE DEVIATION POINTER - Indicates deviation from ILS glide
slope.
Figure 1. Cessna 300 Nav/Com (Type RT-385A), Operating Controls
and Indicators (Sheet 3 of 3)
1 July 1979
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CESSNA 300 NAV/COM
(TYPE RT-385A)
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