Trig makes the world’s smallest and lightest Mode S certified GA transponders. The TT21 Trig compact transponder can fit into to the tightest panel space. This allows general aviation, light sport and glider pilots to fit other instrumentation or displays that otherwise might not have been possible. The TT21 is a class 2 transponder and our most popular compact transponder model.
The TT21 is a two part transponder with a compact control head; this includes an inbuilt altitude encoder - saving further space and expense. A separate hardware box can be installed anywhere in the airframe. The mounted control head is only 54mm (2 3/25”) deep and can be fitted in panel using a 57mm (2 ¼”) round hole or smaller compact mount, the unit ships with the necessary fittings for both install options. The TT21 unit is highly efficient and is ideal for use via an auxiliary battery in gliders, balloons and foot launched flight.
Trig’s TT21 is a popular compact transponder with 130 watts nominal power output. This is a class 2 transponder which meets international standards for 1090ES ADS-B Out (TSO C166b). The TT21 is ideal for use in flight where a light weight Mode S solution is required and is suitable for IFR and VFR use.
Older mode A and C transponders are now being replaced by Mode S, technology which is optimized for tomorrow’s airspace requirements. The TT21 transponder is easy to operate and with a crisp, bright display it is also easy to read in all lighting conditions. The transponder control head is splash proof too so it’s ideal for open cockpit and seaplane operations.
Customers in the U.S. should be aware that FAA, Federal Aviation Regulations (FAR) 91.227 requires that a compliant ADS-B Out solution uses a Class 1 transponder. The TT21 is a Class 2 device and does not meet this regulation. If you are looking for a class 1 transponder, we recommend the Trig TT22 Transponder which is a Class 1 device and meets this requirement.
|TT21 – Mode S for light aviation||TT22 – Mode S for high performance aircraft|
|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 and 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 (@14V)||idle: 0.15 A active: 0.28 A||idle: 0.15A active: 0.34 A|
|NominalTransmitterPower||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|
|CoolingRequirement||no fan required|
|Dimensions||controller: H 44 x W 63 x L 54 mm transponder in tray: H 48 x W 68 x L 160 mm|