Official PayPal Seal

Avidyne AXP-340 Transponder with Mode 'S'

Avidyne AXP340 Mode 'S' Transponder

Transponder with Mode 'S'




  • Overview
  • Specifications
  • Functionality
  • Image
  • Avidyne Panel Mount Video

AXP340 Mode S Transponder with ADS-B Out

Avidyne’s AXP340 Mode S Transponder provides an ADS-B Out solution for general aviation aircraft in a simple, easy-to-use, plug & play design.

Avidyne AXP340

AXP340 ADS-B Mode S Transponder

The AXP340 transponder is a panel-mounted Class 1 Mode S Level 2 Datalink Transponder, with support for 1090MHz Extended Squitter (ES), that meets all the current requirements for Mode S elementary surveillance transponders for both IFR and VFR flight. As a slide-in replacement for existing KT76A/KT78A transponders, the AXP340 is designed to easily upgrade existing Mode A/C equipment to Mode S, while adding additional functionality like a Direct-entry Numeric Keypad, Pressure Altitude & GPS Lat/Lon readout, Flight ID entry, one-touch VFR code entry, an easy-to-use Stop Watch Timer, Flight Timer, and Altitude Alerter.

Meeting the Mandate for ADS-B

The AXP340 also supports the latest Version 2 1090 MHz Automatic Dependent Surveillance Broadcast (ADS-B) Extended Squitter, known as “ADS-B out”. Equipping with ADS-B Out will be required in most U.S. airspace by 2020. The AXP340, when linked to a suitable GPS receiver, transmits position information to appropriately-equipped ground stations and other aircraft. This provides improved airborne surveillance, provides vital information for airport ground surveillance, and is a key feature of future airspace plans.

TAS600 Air volume


The AXP340 provides an affordable and lightweight Mode S Surveillance and ADS-B Out solution for fixed wing and helicopter operators.




Garmin Replacement

The AXP340 is a slide-in replacement for the venerable KT76A transponder, making it a great choice for upgrades, as well as for new installations. (Additional wiring required for ADS-B functionality.)

Physical and Performance:
Unit dimensions, WxHxD: 6.30"W x 1.57"H x 9.4"D (160 x 40 x 239 mm)
Weight: 2.98 lb (01.35 kg)
Power: 10-33 volts Idle: 0.22 A, Active: 0.45 A
240W nominal at connector
Other Features:
Environmental: -20 to +55 C, 35,000ft.
No external cooling fan required.
GPS Compatibility: Avidyne GPS (including R9)
Garmin GNS430W/530W Series
Garmin GTN650/750 Series
FreeFlight Model 1201/1204
NexNav mini-T
Other Interfaces: Gray Code & Serial Altitude Inputs
Serial Altitude Output
External Standby Input
Weight on Wheels Input
External Ident Input
Type: Class 1 Mode S Level 2 Datalink
Elementary Surveillance
Enhanced Surveillance
Certification: TSO C112c, TSO C166b 
ETSO 2C112b, ETSO C166b
Compliance: ED73B, DO160E, DO178B level B, DO181C, DO260B, AC 20-165 

AXP340 Mode S Transponder with ADS-B Out

Avidyne’s AXP340 Mode S Transponder provides an ADS-B Out solution for general aviation aircraft in a simple, easy-to-use, plug & play design.

Avidyne AXP340

The Mode S Advantage

The AXP340 delivers 240 Watts of transmitter power, and responds to both legacy Mode A/C interrogations and to Mode S interrogations from both ground radar and airborne collision avoidance systems. In the Mode S environment (S stands for Select), a Mode S interrogator can selectively address a single transponder. This allows accurate position plotting with lower reply rates, which in turn reduces frequency congestion and interference.

Your 1090Mhz ADS-B Solution

Coupled with any of Avidyne‘s TAS600A ADS-B capable Traffic Advisory Systems, the AXP340 provides full ADS-B surveillance capability to meet the upcoming mandates for flight internationally and above and below FL180 in the U.S. The AXP340 transmits the required ADS-B Out signals including your aircraft’s GPS-derived position, along with ground track, ground speed and altitude information. The TAS600A provides ADS-B In, allowing you to receive the ADS–B signals from ground radar and from other 1090MHz ADS-B – equipped aircraft and display both ADS-B and non-ADS-B traffic simultaneously for optimal situational awareness and safety.

ads-b solution

The AXP340 & TAS600A combine to provide complete 1090MHz ADS-B solution. ADS-B & TAS traffic can be displayed on a wide range of displays including Avidyne’s EX600 and MHD300 (shown here), providing the highest level of situational awareness and safety.

The Avidyne AXP-340 Mode 'S' Transponder

Avidyne AMX-240 Audio Panel

Watch the Avidyne Panel Mount Video.