TT21 Transponder

TT21 - Class 2 – Mode S and 1090ES ADS-B Out transponder

Trig makes the world’s smallest Mode S certified GA transponders. The TT21 Trig compact transponder can fit into to the tightest panel space. This allows other instrumentation or avionics to be accommodated, providing a genuine benefit in any installation.

Product features

The TT21 is a class 2 transponder and our most popular compact transponder model, with the following features:

• Takes minimal panel space, fits in a standard 57mm round instrument hole or smaller compact mount
• Comes with integrated altitude encoder
• Certified for IFR / VFR flight
• Certified class 2 transponder 130 watts nominal output
• Manual dimming feature (adjustable backlight)
• Low weight – 440g (0.8 lbs)
• Low power consumption
• 1090ES ADS-B Out capable
• Free European minor change approvals
• EASA ETSO and FAA TSO Certification – includes TSO C166b the latest ADS-B standard
• Unbeatable value and quality – designed and manufactured in the U.K.
• Two year worldwide warranty

Product description

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, ideally suited for use via an auxiliary battery in either gliders, balloons or foot launched flight.

Trig’s TT21 has a 130 watts nominal power output, making it a class 2 transponder that 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 both IFR and VFR use.

Older mode A and C transponders are now being replaced by Mode S technology which is optimised for tomorrow’s airspace requirements. The TT21 transponder is easy to operate and with a crisp, bright display. It is easy to read in all lighting conditions and features manual dimming. The transponder control head is splash proof too so it’s ideal for open cockpit and seaplane operations.

You may wish to consider our TN70 product line, this contains all the main components to provide an ADS-B Out solution in one box and can be specified with a TT21. 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 TT22 is a Class 1 device and meets this requirement. The TT21 is a Class 2 device and does not meet this regulation.

All Trig products come with a two year warranty, supported by our global network of Approved Trig Dealers and Approved Trig Service Centers in the U.S. and Australia.