CERTIFICATION APPROVAL:
TSO Authorization
COMPLIANCE:
Optional
SYSTEM:
GTR225 / GTR225A / GTR225B / GNC255A / GNC255B
PURPOSE:
This Service Bulletin announces the availability of GTR 225/GNC 255 Display Software Version 2.11, USB Software Version 2.02, COM Software Version 2.20, and COM FPGA Version 2.4.
Display Software Version 2.11/USB Software Version 2.02 contain the following changes from Display Software Version 2.02/USB Software Version 2.01:
- Added “Internal” COM sidetone configuration to improve the audio quality of the COM sidetone
- Added configuration to allow the COM sidetone volume to change when the COM receiver volume is adjusted
- Added automatic intercom squelch level adjustment setting (Intercom Auto VOX) to improve the performance of the intercom
- Added setting to mute the auxiliary input during COM RX
- Added setting to mute the intercom during COM RX
- Added Advanced COM RX Squelch configuration to allow the COM radio sensitivity settings to be adjusted independently for low, mid, and high frequencies in both 8.33 kHz and 25 kHz channel spacing modes
- Changed display of station identifiers for active and standby COM and NAV frequencies when connected to a GPS position source to match other Garmin products
Display Software Version 2.11 contains the following changes from Display Software Version 2.10:
- The COM sidetone volume will be at the installer-configured level after power cycling the unit rather than being at a default level
COM Software Version 2.20/FPGA Version 2.4 contain the following changes from COM Software Version 2.13/FPGA Version 2.3:
- Improved the performance of the intercom Manual VOX mode
- Improved the intercom audio quality
- Reduced noise burst (“Squelch Tail”) that occurs at the end of a reception
- Reduced random squelch breaks (popping)