Which CDI indicators will works with the GNC NAV/COM?
For a new glideslope and LOC/VOR CDI receiver the GI 106A is the first recommendation under part number 11-05768.
Will the GTR & GNC units operate without purchasing and maintaining a current database subscription from Garmin?
Yes, the database is an optional feature on the GTR & GNC series.
Will these radios integrate with the Dynon 180 like the SL 30 model does?
Yes, the GNC series will still output the NAV like the older SL 30 units.
Is the a wiring like with the 430W units to a Sandel 3308?
Yes the Garmin GNC Nav/Com has a 429 Arinc output which can go to the Sandel.
What size circuit breaker does the GNC 255A 10W version require? What is the maximum current draw?
For the Com side 5A @ 28V & 10A 14V and for the Nav side 2A @ 28V & 4A @ 14V. The amp draw varies based on the Com and Nav as well as 14 and 24 volt systems. Always refer to the manual before installation.
What antennas are recommended for the GNC 255A Nav/Com radio? Is there a wing tip antenna that can be used for this radio?
There is no recommended antenna for any radio as almost any Com and Nav antenna can be used. They are built for different speed ratings, mounting locations and some are certified (TSO'd) and some are for experimental aircraft only. Type antennas in the search box on Aircraft Spruce website for our product selection.
Archer and Advanced composite are two wing tip types but both are not certified (TSO'd) as they are intended for experimental aircraft only.
Does the integrated intercom offer an auxiliary audio input (for something like an MP3 player)?
No, it is a basic intercom, for a stereo option or 3.5mm input you will need to go with an external intercom.
What voltage do these units operate on?
It can operate on a 14 or 28 volt system.
Is it possible to purchase the installation tray and wiring harness separately from the GNC 255A NAV/COM unit?
It is possible but we will have to special order this for you and may not cost or have the same lead-time as Garmin does not stock it this way. Please call us and we can get pricing and lead-times.
Does the GNC 255A provide the same radial display of the standby VOR like the SL 30? With the primary VOR/LOC frequency providing guidance to your HSI or CDI, the standby frequency can be tuned to a second VOR to display the current radial on which your aircraft is flying.
In speaking with Garmin, the GNC 255 does not have the standby VOR like the SL 30.
Is the unit compatible with my existing KI-209 GS/Loc CDI?
Per the manufacturer: Yes all Garmin GNC 255's are compatible with the King KI-209.
What does the wiring harness include for the Garmin VHF NAV / COM GNC 255A / B? Does it include the harness to interface with the indicator head?
No, the stock harness (11-11354 or 11-11355) does not include connections to the CDI. Please see part 11-13040 or 11-13041 for the custom harness which includes CDI connections.
Does the GNC 255A interface with portable GPS Garmin 695/696?
Yes, you will need the power/data cable part number 11-07056.
Is the GNC 255a or 255B a direct replacement for the SL30 without harness modification
No, the upgrade to a GNC will require a new install of rack, connector and harness.