Part #: 011-00728-00

Model: GTX-320A

Garmin - Transponder
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Part Number :

GTX 320A
  • 200 watt power output
  • 100% solid state transmitter
  • 14 or 28 volt operatio without need for external voltage converters or dropping resistors
  • Optional adapters available for upgrading into existing installations of selected Narco, King, and ARC transponders
  • Two year warranty
  • TSO C74c Class 1A certified to 50000 ft.
TSO Compliance: C74c Class 1A Temperature Range: -20C to +55C
Weight: 2.1 lbs Dimensions: 8.2" L x 6.25" W x 1.63" H
Altitude: 50,000 feet Power Requirements: 11.0 to 33.0 VDC; Max power input: 12 watts
Humidity: 95% @ +55C for 16 hours; 85% @ +38C for 32 hours Transmitter Frequency:   1090 MHz
Transmitter Power: 200 watts nominal Receiver Sensitivity: -74 dm nominal for 90% replies
Mode A Capability: 4096 ident codes Mode C Capability: 100 foot increments from -1000 to 63,000 feet
Part NumberTransponder Description:
010-00247-01 With details above


- Transponder (unit only)
Price Condition Status

Click on a question below to see the answer. If you have a question about this model that is not answered below, please contact

Yes, the GTX-327 utilizes the same mounting rack and mating connector as the GTX-320 and GTX-320A. The GTX-327 offers a few additional features but matches the standard connection pins as the GTX-320 and GTX-320A.
The GTX-320 and GTX-320A are identical in relation to fit and function. Both are Mode C transponders and are operated identically. For manufacturing efficiency reasons, Garmin discontinued the GTX-320, changed the board design, and released the GTX-320A in its place.
Yes, anytime a transponder is removed or replaced an altitude correlation between what the transponder is reporting and what is displayed on the altimeter needs to be performed. This is outlined in FAA CFR Part 91.413. This regulation indicates that following any installation or maintenance of a transponder where data correspondence error could be introduced, the integrated system has been tested, inspected, and found to comply with paragraph (c), appendix E. Furthermore, these references indicate that an integration test between the altitude reporting equipment and transponder system must be conducted.

For complete information, please refer to these FAA regulations or contact Southeast Aerospace Tech Support team at

Although some manufacturers call out specific transponder antennas in their installation manuals, almost any transponder antenna can be used with any transponder. Various models are available based on the screw hole pattern desired and the speed & drag considerations based on the aircraft type.

For smaller general aviation aircraft, Southeast Aerospace recommends the stub type AV-22 or CI-101 antenna.



For medium to larger aircraft, Southeast Aerospace recommends the blade type CI-105 or AV-74 antenna.


Ultimately, it is the responsibility of the installer or installing agency to determine what antenna is suitable for the aircraft application.




Newly Overhauled parts obtained from Garmin are designated with an N in their part number. This usually follows the 010- in the part number. As with most Garmin 010 part numbers, the N part numbers are for ordering purposes only and do not actually appear on the dataplate of the unit.