TT21 Mode S Transponder

Estimated Availability: October 2021

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Manufacturer: TRIG

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• Takes minimal panel space, easy installation

Integrated altitude encoder

Certified class 2 transponder 130 watts nominal output – C166

Low weight – 0.8 lbs

Low power consumption

1090ES ADS-B Out capable

Certified to FAA TSO C166b

Unbeatable value and quality – designed and manufactured in the U.K.

Two year worldwide warranty

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 airplane owners to fit other instrumentation or displays that otherwise might not have been possible.

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 control head can be installed in the panel either as a 2 ¼” round hole or smaller compact mount, the unit ships with the necessary fittings for both install options. The TT22 unit is highly efficient and is ideal for use via an auxiliary battery in gliding or lighter than air 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. The TT21 unit is highly efficient and is ideal for use via an auxiliary battery in gliding or lighter than air flight.

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. Mode A and C transponders are now being replaced by Mode S. This technology is more advanced and is optimised for tomorrow’s airspace requirements.  All Trig products come with a two year warranty.

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.

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