Garmin GNC 420W Pilots Guide - Page 29

GNC 420(A) Pilot’s Guide and Reference

2-1

SECTION 2

COM

190-00140-20

Rev. K

SECTION 2:

COM

2.1

COMMUNICATING USING THE GNC 420

The GNC 420 features a digitally-tuned VHF COM radio

that provides a seamless transition from communication

to navigation, bringing the two most important functions

in flying together in one panel-mounted unit.

The GNC

420’s COM radio operates in the aviation voice band, from

118.000 to 136.975 MHz, in 25 kHz steps (default).

For

European operations, a COM radio configuration to allow

for 8.33 kHz steps is also provided (Section 9.5, Setup 2

Page: COM Configuration).

Volume

COM radio

volume is adjusted using the

COM Power/

Volume

Knob.

Turn the

COM Power/Volume

Knob

clockwise to increase volume, or counterclockwise to

decrease volume.

Squelch

The COM radio features an

automatic squelch,

providing maximum sensitivity to weaker signals while

rejecting many localized noise sources.

The pilot may

wish to override this automatic squelch function when

listening to a distant station or when setting the desired

volume level.

The

COM Power/Volume

Knob allows the

pilot to disable the

automatic squelch and keep the COM

audio open continuously.

Overriding the automatic squelch:

1)

Press the

COM Power/Volume

Knob

momentarily.

2)

Press the

COM Power/Volume

Knob again

to return to automatic squelch operation.

COM Window and Tuning

Communication frequencies are selected with the

tuning cursor in the standby COM frequency field (Figure

2-1), using the small and large

left

knobs to tune the

desired frequency.

The standby frequency always appears

below the active frequency.

The active frequency is

the frequency currently in use for transmit and receive

operations.

Figure 2-1

‘RX’ Receive Indication

‘RX’ Receive Indication

Standby COM Frequency Field

A frequency may also be quickly selected from the

database by simply highlighting the desired frequency on

any of the main pages and pressing the

ENT

Key.

This

process is referred to as auto-tuning.

Once a frequency is

selected in the standby field, it may be transferred to the

active frequency by pressing the

COM Flip-flop

Key.

Section	Page
SECTION 1: INTRODUCTION	9
1.1 Accessories and Packing List	9
1.2 Key and Knob Functions	10
1.3 Takeoff Tour	13
SECTION 2: COM	29
2.1 Communicating Using the GNC 420	29
SECTION 3: NAV PAGES	35
3.1 Main Page Groups	35
3.2 NAV Page Group	36
3.3 Default NAV Page	36
3.4 Map Page	39
3.5 TERRAIN Page	49
3.6 NAV/COM Page	52
3.7 Position Page	54
3.8 Satellite Status Page	57
3.9 Vertical Navigation Page	59
SECTION 4: DIRECT-TO NAVIGATION	63
4.1 Overview	63
SECTION 5: FLIGHT PLANS	69
5.1 Flight Plan Catalog Page	69
5.2 Active Flight Plan Page	76
SECTION 6: PROCEDURES	85
6.1 Approaches, Departures, and Arrivals	85
6.2 Non-Precision Approach Operations	87
6.3 Points to Remember for All Approaches	110
SECTION 7: WPT PAGES	111
7.1 WPT Page Group	111
7.2 Airport Location Page	114
7.3 Airport Runway Page	115
7.4 Airport Frequency Page	116
7.5 Airport Approach Page	118
7.6 Airport Arrival Page	121
7.7 Airport Departure Page	123
7.8 Intersection Page	124
7.9 NDB Page	125
7.10 VOR Page	125
7.11 User Waypoint Page	126
SECTION 8: NRST PAGES	135
8.1 NRST Page Group	135
8.2 Nearest Airport Page	138
8.3 Nearest Intersection Page	140
8.4 Nearest NDB Page	140
8.5 Nearest VOR Page	141
8.6 Nearest User Waypoint Page	141
8.7 Nearest Center (ARTCC) Page	142
8.8 Nearest Flight Service Station (FSS) Page	143
8.9 Nearest Airspace Page	144
SECTION 9: AUX PAGES	149
9.1 AUX Page Group	149
9.2 Flight Planning Page	150
9.3 Utility Page	160
9.4 Setup 1 Page	168
9.5 Setup 2 Page	175
SECTION 10: TERRAIN	181
10.1 Introduction	181
10.2 TERRAIN Page	183
10.3 TERRAIN Alerts	184
10.4 Database Information for TERRAIN	189
SECTION 11: ADDITIONAL FEATURES	191
11.1 Traffic Information Service (TIS)	191
11.2 GTS 8XX Traffic Systems	201
11.3 Weather Data Link Interface	208
SECTION 12: FAULT DETECTION AND EXCLUSION	227
12.1 Detection and Exclusion	227
12.2 Pre-Departure Verification of FDE	228
SECTION 13: MESSAGES, ABBREVIATIONS, AND NAV TERMS	229
13.1 Messages	229
13.2 Abbreviations	236
13.3 Navigation Terms	239
Appendix A: Data Card Use	241
Appendix B: Specifications	243

Garmin GNC 420W Pilots Guide - Page 29

COM, 2.1 Communicating Using the GNC 420, Overriding the automatic squelch

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