Contents
 GNC 255A/255B
 November
 Limited Warranty
 190-01182-01 Rev. a
 Iii
 Operation
 US Toll Free Canada Toll Free
Product Registration and Support
 Record of Revisions
 Contents
 2.1
2.2
2.3
 Index Index-1
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 Product Description
Getting Started
 Power/Com Volume/Squelch Knob
Nav Volume/ID Knob
Pilot Controls
 FLIP/FLOP Key
Tuning LARGE/SMALL Concentric Cursor Knobs
5 C/N Com/Nav Key
OBS Key
 USB Port
Func Function Key
MON Monitor Key
 Power On
Com Radio
Selecting a Com Frequency
 Monitoring the Standby Com Channel
Saving a Com Channel
After selecting the desired characters, press ENT
 After making a selection, press ENT
Description
 Frequency Database Reverse Look-Up
Com Database Look-Up
 Emergency Channel
Stuck Mic
Remote Frequency Selection Control
 Nav Radio
Selecting a Nav Frequency
Saving a Nav Channel
 01-36
Listening to the Nav Audio Channel
 14 CDI Display
OBS Mode
 15 DST Data Display
Distance/Speed/Time DST Display
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 Functions Description
Functions
 Com Frequencies
Recent Com Frequencies
Turn the Small knob to select an Entry
 Press the CLR key to delete this User frequency
Com User Frequencies
 Frequencies. Press ENT
Editing a Com User Frequency
 Com Database Frequencies
Com Database Frequencies
 Nearest APT function. Then, press ENT
Com Nearest Airports APT
 Turn Small Knob To Scroll Through Available Frequencies
Com Nearest Area Control Center ACC Frequencies
 13 Com Nearest FSS Frequencies
Com Nearest Flight Service Station FSS Frequencies
 14 Com Nearest Weather Frequencies
Com Nearest Weather WX Frequencies
 Recent Nav Frequencies
Nav Frequencies
 Press the ENT key to delete the displayed frequency
Nav User Frequencies
 Editing a Nav User Frequency
 21 Nav Database Frequencies
Nav Database Frequencies
 Nav Nearest VOR
When duplicate identifiers are found, press ENT
 Adjust Intercom
ICS Configuration
Turn the Small knob to display the available VORs
Functions display
 Turn the Small knob to turn the Aux Audio On or Off
Aux Audio
 Speaker On/Off
Intercom On/Off
Intercom On/Off function. Then, press the ENT key
Speaker On/Off function. Then, press ENT
 Com Spacing
System Configuration
 34 Set Display Brightness
Display Brightness
 Database Info
Display Contrast
Display Contrast function. Then, press the ENT key
Database Version function. Then, press the ENT key
 Load Database function. Then, press the ENT key
Load Database
 Serial Number
Software Version
Software Version function. Then, press the ENT key
Press the Func key to return to the main menu
 Timers
Setting Up the Count Down Timer
To select a starting timer value
 Viewing Timers in the Com Display
Setting Up the Count Up Timer
Pressing CLR and then ENT will reset the displayed Timer
Pressing ENT twice will stop the displayed Timer
 48 Count Down Timer Value Now Counting Up
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 Appendix
Troubleshooting
 Or disabled via a Remote mounted
It can be enabled
If in Lock Out mode
Calibration error Recalibrate resolver
 Updating the Frequency Database
 Messages
 Switch has been
Power has been Re-apply power to the unit
Verify glideslope deviation
Property with
 Installations
All installations
Remote com
Been in pressed
 Nav radio is Contact dealer for service
Not communicating
Property with System
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 Index
 Remote frequency control 2-5 Reverse look-up 2-4 Revisions