GNC255A/255B Pilot's Guide
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... your local Garmin Authorized Service Center. A Garmin GNC 255A/255B Pilot's Guide i and 90 days for new Remote-Mount and Panel-Mount products; Online Auction Purchases: Products purchased through a Garmin Authorized Service Center; Online auction confirmations are obtained and/or used in lieu of intended distribution. International Purchases: A separate warranty may be provided by the local in the area of repair. Distributor...
... your local Garmin Authorized Service Center. A Garmin GNC 255A/255B Pilot's Guide i and 90 days for new Remote-Mount and Panel-Mount products; Online Auction Purchases: Products purchased through a Garmin Authorized Service Center; Online auction confirmations are obtained and/or used in lieu of intended distribution. International Purchases: A separate warranty may be provided by the local in the area of repair. Distributor...
GNC255A/255B Pilot's Guide
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... within this device may cause undesired operation. If you have any user-serviceable parts. WARNING: For safety reasons, GNC 255 operational procedures must be made by an authorized Garmin service center. It is very important to change and may differ slightly from the actual equipment. Databases used in the system must be updated regularly in accordance with 8.33 kHz COM channel spacing, the radio should only...
... within this device may cause undesired operation. If you have any user-serviceable parts. WARNING: For safety reasons, GNC 255 operational procedures must be made by an authorized Garmin service center. It is very important to change and may differ slightly from the actual equipment. Databases used in the system must be updated regularly in accordance with 8.33 kHz COM channel spacing, the radio should only...
GNC255A/255B Pilot's Guide
Page 6
... for your unit, please contact your unit handy, connect to clean the lens using an eyeglass lens cleaner which is very sensitive to radio communications. The display surface is coated with Part 15 of this device must accept any interference received, including interference that may cause harmful interference to skin oils, waxes and abrasive cleaners. iv Garmin GNC 255A/255B Pilot's Guide 190...
... for your unit, please contact your unit handy, connect to clean the lens using an eyeglass lens cleaner which is very sensitive to radio communications. The display surface is coated with Part 15 of this device must accept any interference received, including interference that may cause harmful interference to skin oils, waxes and abrasive cleaners. iv Garmin GNC 255A/255B Pilot's Guide 190...
GNC255A/255B Pilot's Guide
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... Operation 2-1 2.1 Power On 2-1 2.2 Com Radio 2-1 2.2.1 Selecting a Com Frequency 2-1 2.2.2 Monitoring the Standby Com Channel 2-2 2.2.3 Saving a Com Channel 2-2 2.2.4 Com Database Look-Up 2-4 2.2.5 Frequency Database Reverse Look-Up 2-4 2.2.6 Emergency Channel 2-5 2.2.7 Stuck Mic 2-5 2.2.8 Remote Frequency Selection Control 2-5 2.3 Nav Radio 2-6 2.3.1 Selecting a Nav Frequency 2-6 2.3.2 Saving a Nav Channel 2-6 2.3.3 Listening to the Nav Audio Channel 2-7 2.4 OBS Mode 2-8 2.5 Distance/Speed/Time (DST) Display 2-9 190-01182-01 Rev. A Garmin GNC 255A/255B Pilot's Guide vii...
... Operation 2-1 2.1 Power On 2-1 2.2 Com Radio 2-1 2.2.1 Selecting a Com Frequency 2-1 2.2.2 Monitoring the Standby Com Channel 2-2 2.2.3 Saving a Com Channel 2-2 2.2.4 Com Database Look-Up 2-4 2.2.5 Frequency Database Reverse Look-Up 2-4 2.2.6 Emergency Channel 2-5 2.2.7 Stuck Mic 2-5 2.2.8 Remote Frequency Selection Control 2-5 2.3 Nav Radio 2-6 2.3.1 Selecting a Nav Frequency 2-6 2.3.2 Saving a Nav Channel 2-6 2.3.3 Listening to the Nav Audio Channel 2-7 2.4 OBS Mode 2-8 2.5 Distance/Speed/Time (DST) Display 2-9 190-01182-01 Rev. A Garmin GNC 255A/255B Pilot's Guide vii...
GNC255A/255B Pilot's Guide
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... a Nav User Frequency 3-12 3.3.3 Nav Database Frequencies 3-13 3.3.4 Nav Nearest VOR 3-14 3.4 ICS Configuration 3-15 3.4.1 Adjust Intercom 3-15 3.4.2 Aux Audio 3-16 3.4.3 Intercom On/Off 3-17 3.4.4 Speaker On/Off 3-17 3.5 System Configuration 3-18 3.5.1 Com Spacing 3-18 3.5.2 Display Brightness 3-19 3.5.3 Display Contrast 3-20 3.5.4 Database Info 3-20 3.5.5 Load Database 3-21 3.5.6 Software Version 3-22 3.5.7 Serial Number 3-22 3.6 Timers 3-23 3.6.1 Setting Up the Count Down Timer 3-23 3.6.2 Setting Up the Count Up Timer 3-24 viii Garmin GNC 255A/255B Pilot's Guide...
... a Nav User Frequency 3-12 3.3.3 Nav Database Frequencies 3-13 3.3.4 Nav Nearest VOR 3-14 3.4 ICS Configuration 3-15 3.4.1 Adjust Intercom 3-15 3.4.2 Aux Audio 3-16 3.4.3 Intercom On/Off 3-17 3.4.4 Speaker On/Off 3-17 3.5 System Configuration 3-18 3.5.1 Com Spacing 3-18 3.5.2 Display Brightness 3-19 3.5.3 Display Contrast 3-20 3.5.4 Database Info 3-20 3.5.5 Load Database 3-21 3.5.6 Software Version 3-22 3.5.7 Serial Number 3-22 3.6 Timers 3-23 3.6.1 Setting Up the Count Down Timer 3-23 3.6.2 Setting Up the Count Up Timer 3-24 viii Garmin GNC 255A/255B Pilot's Guide...
GNC255A/255B Pilot's Guide
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... Photo Sensor Locking Screw Frequency Transfer (FLIP/FLOP) Key USB Port Nav (VLOC) Volume, Nav ID On/Off Frequency Monitor Key Com or Nav Frequency Selection OBS Selection LARGE and SMALL Knobs (Frequency Adjust) Enter Key Clear Data Key Function Selection To/From Selection Figure 1-1 GNC 255 Front Panel Description 190-01182-01 Rev. The GNC 255 is available in a small footprint at a very affordable price. A Garmin GNC 255A/255B Pilot's Guide 1-1 The GNC 255's Com radio operates...
... Photo Sensor Locking Screw Frequency Transfer (FLIP/FLOP) Key USB Port Nav (VLOC) Volume, Nav ID On/Off Frequency Monitor Key Com or Nav Frequency Selection OBS Selection LARGE and SMALL Knobs (Frequency Adjust) Enter Key Clear Data Key Function Selection To/From Selection Figure 1-1 GNC 255 Front Panel Description 190-01182-01 Rev. The GNC 255 is available in a small footprint at a very affordable price. A Garmin GNC 255A/255B Pilot's Guide 1-1 The GNC 255's Com radio operates...
GNC255A/255B Pilot's Guide
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... Annunciator Active Frequency Annunciator Com Mode Annunciator Active Nav Frequency Com Volume Bar Graph Standby Frequency Annunciator Figure 1-2 Com Volume and Squelch Display Description The Com radio features an automatic squelch to automatic squelch operation. To override the automatic squelch, press the Power/Com Volume/Squelch knob momentarily. 1.2 Pilot Controls The GNC 255 controls have been designed to simplify operation of the bezel controls audio volume for the Com radio. You may override the squelch function by pressing the Power/Com Volume/Squelch...
... Annunciator Active Frequency Annunciator Com Mode Annunciator Active Nav Frequency Com Volume Bar Graph Standby Frequency Annunciator Figure 1-2 Com Volume and Squelch Display Description The Com radio features an automatic squelch to automatic squelch operation. To override the automatic squelch, press the Power/Com Volume/Squelch knob momentarily. 1.2 Pilot Controls The GNC 255 controls have been designed to simplify operation of the bezel controls audio volume for the Com radio. You may override the squelch function by pressing the Power/Com Volume/Squelch...
GNC255A/255B Pilot's Guide
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Switching between Com frequencies is installed with an external converter. 1.2.7 T/F (To/From) Key Press the T/F key to switch between the bearing TO or radial FROM the active VOR. The T/F key does not operate for tuning frequencies and data entry. The T/F page also shows Distance/Speed/ Time information. A Garmin GNC 255A/255B Pilot's Guide 1-3 The OBS page will be disabled if the unit is disabled while you are used for Localizer...
Switching between Com frequencies is installed with an external converter. 1.2.7 T/F (To/From) Key Press the T/F key to switch between the bearing TO or radial FROM the active VOR. The T/F key does not operate for tuning frequencies and data entry. The T/F page also shows Distance/Speed/ Time information. A Garmin GNC 255A/255B Pilot's Guide 1-3 The OBS page will be disabled if the unit is disabled while you are used for Localizer...
GNC255A/255B Pilot's Guide
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... categories for updating the database. 1-4 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. NOTE: Garmin recommends the use of a USB 2.0 compatible USB flash drive for the following: the Com Radio, Nav Radio, ICS Configuration, System Configuration, and Timer. Pressing the FUNC key a second time exits the Function mode. 1.2.11 MON (Monitor) Key The MON (Monitor) key will engage the monitor function where the Standby frequency may...
... categories for updating the database. 1-4 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. NOTE: Garmin recommends the use of a USB 2.0 compatible USB flash drive for the following: the Com Radio, Nav Radio, ICS Configuration, System Configuration, and Timer. Pressing the FUNC key a second time exits the Function mode. 1.2.11 MON (Monitor) Key The MON (Monitor) key will engage the monitor function where the Standby frequency may...
GNC255A/255B Pilot's Guide
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2 BASIC OPERATION 2.1 Power On Turn the GNC 255 on by either turning the Power/Com Volume/ Squelch knob clockwise to turn the power on or, if installed, turning on the master switch that powers the radios. 2.2 Com Radio 2.2.1 Selecting a Com Frequency New frequencies are first selected as a Standby frequency and then toggled to change the values in one MHz steps. 3. Turn the SMALL knob to the Active side with multiple types will have an...
2 BASIC OPERATION 2.1 Power On Turn the GNC 255 on by either turning the Power/Com Volume/ Squelch knob clockwise to turn the power on or, if installed, turning on the master switch that powers the radios. 2.2 Com Radio 2.2.1 Selecting a Com Frequency New frequencies are first selected as a Standby frequency and then toggled to change the values in one MHz steps. 3. Turn the SMALL knob to the Active side with multiple types will have an...
GNC255A/255B Pilot's Guide
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... saved into the Com User Frequency database from the user frequency list. Press ENT. Number of the Standby frequency. The Com User Frequency database can hold up to move the cursor. Turn the LARGE knob to 15 frequencies. After selecting the desired characters, press ENT. 2-2 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. Turn the SMALL knob to the Active frequency. NOTE: When switching from 8.33 kHz to 25 kHz mode...
... saved into the Com User Frequency database from the user frequency list. Press ENT. Number of the Standby frequency. The Com User Frequency database can hold up to move the cursor. Turn the LARGE knob to 15 frequencies. After selecting the desired characters, press ENT. 2-2 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. Turn the SMALL knob to the Active frequency. NOTE: When switching from 8.33 kHz to 25 kHz mode...
GNC255A/255B Pilot's Guide
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... multiple times to the receive mode on units configured for approximately two seconds. The following message will return to scroll the entire preset frequency list through the Standby frequency box (the list will become the Standby Frequency. The remote recall switch can be inserted into the unit's Standby frequency box. Remote Frequency Selection only functions on the selected frequency. Figure 2-9 Emergency Channel 2. A Garmin GNC 255A/255B Pilot's Guide 2-5 Press and hold...
... multiple times to the receive mode on units configured for approximately two seconds. The following message will return to scroll the entire preset frequency list through the Standby frequency box (the list will become the Standby Frequency. The remote recall switch can be inserted into the unit's Standby frequency box. Remote Frequency Selection only functions on the selected frequency. Figure 2-9 Emergency Channel 2. A Garmin GNC 255A/255B Pilot's Guide 2-5 Press and hold...
GNC255A/255B Pilot's Guide
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... Display 2-8 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. A Each dot indicates two degrees deflection with an external CDI/HSI, the OBS radial of your system is the decoded Nav Identifier from the Morse code broadcast by the station. 1. NOTE: The Identifier is configured with ten degrees full deflection to change the displayed OBS values. 2.4 OBS Mode If your remote display will be on the screen...
... Display 2-8 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. A Each dot indicates two degrees deflection with an external CDI/HSI, the OBS radial of your system is the decoded Nav Identifier from the Morse code broadcast by the station. 1. NOTE: The Identifier is configured with ten degrees full deflection to change the displayed OBS values. 2.4 OBS Mode If your remote display will be on the screen...
GNC255A/255B Pilot's Guide
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... Config Recent Freqs User Freqs Database Nearest Apt Nearest ACC Nearest FSS Nearest WX Recent Freqs User Freqs Database Nearest VOR Adjust Intercom Aux Audio Intrcom On/Off Speaker On/Off SYS Config Com Spacing DSPL Brt DSPL Contrast Database Info Load Database Software Ver Serial Number Timers Count Down ENT - Start/Stop CLR - Reset Push CRSR - Accept Count Up ENT - A Garmin GNC 255A/255B Pilot's Guide 3-1
... Config Recent Freqs User Freqs Database Nearest Apt Nearest ACC Nearest FSS Nearest WX Recent Freqs User Freqs Database Nearest VOR Adjust Intercom Aux Audio Intrcom On/Off Speaker On/Off SYS Config Com Spacing DSPL Brt DSPL Contrast Database Info Load Database Software Ver Serial Number Timers Count Down ENT - Start/Stop CLR - Reset Push CRSR - Accept Count Up ENT - A Garmin GNC 255A/255B Pilot's Guide 3-1
GNC255A/255B Pilot's Guide
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.... Updating will begin automatically. Turn the SMALL knob to view the Load Database function. Insert the supplied cable into the other end of the GNC 255. 2. NOTE: Garmin recommends the use of a USB 2.0 compatible USB flash drive for easily updating the system databases. Verify the database version on the top right corner of the cable. A Garmin GNC 255A/255B Pilot's Guide 3-21 3.5.5 Load Database The GNC 255 has a USB connector to allow for updating the database. 1. Figure 3-38 Database Update Display...
.... Updating will begin automatically. Turn the SMALL knob to view the Load Database function. Insert the supplied cable into the other end of the GNC 255. 2. NOTE: Garmin recommends the use of a USB 2.0 compatible USB flash drive for easily updating the system databases. Verify the database version on the top right corner of the cable. A Garmin GNC 255A/255B Pilot's Guide 3-21 3.5.5 Load Database The GNC 255 has a USB connector to allow for updating the database. 1. Figure 3-38 Database Update Display...
GNC255A/255B Pilot's Guide
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... to select the SYS Function. The unit will reset automatically once the database is complete and then remove the memory device and cable. Wait until the updating process is updated. 6. Turn the LARGE knob to the main menu. 3-22 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. Then, press the ENT key. Turn the LARGE knob to the main menu. 3.5.7 Serial Number The serial number of the GNC 255 unit are displayed.
... to select the SYS Function. The unit will reset automatically once the database is complete and then remove the memory device and cable. Wait until the updating process is updated. 6. Turn the LARGE knob to the main menu. 3-22 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. Then, press the ENT key. Turn the LARGE knob to the main menu. 3.5.7 Serial Number The serial number of the GNC 255 unit are displayed.
GNC255A/255B Pilot's Guide
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4 APPENDIX 4.1 Troubleshooting If efforts to 7:00 PM Central Time. http://www.garmin.com https://fly.garmin.com/fly-garmin 190-01182-01 Rev. The Garmin customer service staff will gladly assist you have the following information ready: • System configuration (products, antennas, mounting locations, etc.) • Model No., part number, and serial number • Software versions • Description of the problem • Efforts made to isolate/solve the problem Garmin International, Inc...
4 APPENDIX 4.1 Troubleshooting If efforts to 7:00 PM Central Time. http://www.garmin.com https://fly.garmin.com/fly-garmin 190-01182-01 Rev. The Garmin customer service staff will gladly assist you have the following information ready: • System configuration (products, antennas, mounting locations, etc.) • Model No., part number, and serial number • Software versions • Description of the problem • Efforts made to isolate/solve the problem Garmin International, Inc...
GNC255A/255B Pilot's Guide
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... Can't change active frequency OBS readout displays "---" Possible Cause No power to the GNC 255 Faulty electrical wiring or connection Output disabled or set to a low level Mixed with Com feature No power to Com Mic key connection It can be enabled or disabled via a remote mounted switch or via the menu. Contact dealer Recalibrate resolver 4-2 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. In this case the radio would be...
... Can't change active frequency OBS readout displays "---" Possible Cause No power to the GNC 255 Faulty electrical wiring or connection Output disabled or set to a low level Mixed with Com feature No power to Com Mic key connection It can be enabled or disabled via a remote mounted switch or via the menu. Contact dealer Recalibrate resolver 4-2 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. In this case the radio would be...
GNC255A/255B Pilot's Guide
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... PTT Key Stuck Message Message Description Action COM RADIO Com radio needs service. Check aircraft voltage and reduce electrical load as necessary. Hold remote com transfer key to troubleshooting system operation. Com radio is locked to Com locked to 121.5 MHz. 121.5 MHz. Contact dealer for two seconds. 4-4 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. Com radio is in overtemp or undervoltage mode and transmitting power has been...
... PTT Key Stuck Message Message Description Action COM RADIO Com radio needs service. Check aircraft voltage and reduce electrical load as necessary. Hold remote com transfer key to troubleshooting system operation. Com radio is locked to Com locked to 121.5 MHz. 121.5 MHz. Contact dealer for two seconds. 4-4 Garmin GNC 255A/255B Pilot's Guide 190-01182-01 Rev. Com radio is in overtemp or undervoltage mode and transmitting power has been...
GNC255A/255B Pilot's Guide
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...22, 4-1, 4-3 Frequency monitoring 2-2 Front panel description 1-1 FSS 3-8 Functions 1-4, 3-1 G Getting started 1-1 I ICS 3-15 ID 1-2 Intercom 3-17 K Knobs 1-3 L Locking screw 1-1 M Menus 1-3 Message 4-4 Monitoring 1-4, 2-2 Morse code 1-1 N Nav audio 2-7 Nav database frequencies 3-13 Nav frequencies 3-10 Nav ID 1-2 Nav radio 2-6 Nav;Select frequency 2-6 Nav user frequencies 3-11 Nav volume 1-2 Nearest airport 3-6, 3-7 O OBS mode 1-3, 2-8 P Pilot controls 1-2 Power on 2-1 Power-up 3-22 Product description 1-1 Product Support v, 4-1 190-01182-01 Rev. A Garmin GNC 255A/255B Pilot's Guide Index...
...22, 4-1, 4-3 Frequency monitoring 2-2 Front panel description 1-1 FSS 3-8 Functions 1-4, 3-1 G Getting started 1-1 I ICS 3-15 ID 1-2 Intercom 3-17 K Knobs 1-3 L Locking screw 1-1 M Menus 1-3 Message 4-4 Monitoring 1-4, 2-2 Morse code 1-1 N Nav audio 2-7 Nav database frequencies 3-13 Nav frequencies 3-10 Nav ID 1-2 Nav radio 2-6 Nav;Select frequency 2-6 Nav user frequencies 3-11 Nav volume 1-2 Nearest airport 3-6, 3-7 O OBS mode 1-3, 2-8 P Pilot controls 1-2 Power on 2-1 Power-up 3-22 Product description 1-1 Product Support v, 4-1 190-01182-01 Rev. A Garmin GNC 255A/255B Pilot's Guide Index...
