TT21 Mode S Transponder

Part No:

Manufacturer: TRIG




  • Smallest & lightest Class 2 Mode S Transponder
  • Designed for Light Aviation
  • For a Higher Performance Aircraft Option, View TT22 
  • Class 2 Transponder is suitable for aircraft cruising slower than 175 knots, and operating below 15,00 feet, VFR or IFR.
  • Remote Mount 2 Part Transponder System: panel controller & transponder box 
  • 130 Watts nominal output
  • Control includes an integrated altitude encoder, up to 35,000 ft
  • Total weight just over 1 lb
  • Minimal Panel Space, can be installed in standard 2¼" (57mm) cut-out or compact mounting just 42mm high
  • Simple Installation
  • Controller acts as a configuration module for the system - easily swap transponder box without reprogramming
  • Fully certified and compliant with all transponder requirements TSO approved for European & FAA registered aircraft
  • Includes TIS (Traffic Information Service) functionality
  • NOTE: While the TT21 is capable of 1090ES ADS-B Out with the appropriate GPS, it is NOT an acceptable ADS-B transponder for certified aircraft because of its Class 2 status. (Due to current FAA regulations)
Specification TT21 Transponder TT22 Transponder
Type Transponder Class 2 Mode S level 2els ADS-B Class B0 Transponder Class 1 Mode S level 2els
ADS-B Class B1S
Certification ETSO C88A, C112C, C166A
TSO C88b, C112c, C166b, approved for IFR and VFR flight
Compliance ED-73C, DO-160F, DO-178B Level B, DO-254
Level C, DO-260B, DO-181D
Supply voltage (DC) 9-33 V
Typical consumption (at 14v) idle: 0.15 A active: 0.28 A idle: 0.15A active: 0.34 A
Nominal Transmitter Power 130 W at connector 250 W at connector
Operating temperature for the transponder -40°C to +70°C
for the controller -25°C to +70°C
Cooling requirement no fan required
Weight (hardware back box) 440g / 0.8 lbs
Weight (TC20 control head) 90g / 0.11 lbs
Dimensions (mm) controller: H 44 x W 63 x L 54 mm
transponder in tray: H 48 x W 68 x L 160 mm
Dimensions (inches) controller: H 1.8 x W 2.4 x L 2.1 inches
transponder in tray: H 1.8 x W 2.6 x L 6.2 inches





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