TRIG Mode S Transponders Feature ADS-B Out Readiness


The Trig T21 Mode S transponder is now equipped with a 1090 MHz squitter for ADS-B Out capability.

TRIG Avionics Limited, a UK-based group, has included ADS-B extended squitters in all of its 2010 TT21, TT22 and TT31 Mode S transponders, which range in price from $2200 to $2600, and are available and supported through Southeast Aerospace in Melbourne, Florida.

The TT21 and TT22 models are billed the smallest and lightest Mode S general aviation transponders, weighing just 1 pound (less than 500 grams) and fitting into a standard 2,25-inch instrument panel cutout. The TIS (traffic information service) readouts can be displayed onto a range of Garmin portable GPS products. Both transponders are designed for very light aircraft, including balloons and sailplanes, and can operate with simple battery power.

The TT31 is a direct slide-in replacement transponder for the KT-76A, KT-78A and KT-76C transponders, requiring no installation changes. It weighs 2.8 pounds and sports the same feature set as the TT21 and TT22 models, including the 1090 MHz ADS-B extended squitter for ADS-B Out capability. Designed for both new and legacy panels, the TT31 handles either 14-volt or 28-volt systems without the need for special configuring or dropper resistors. It is also compatible with both parallel and serial altitude encoders and can act as a serial altitude repeater to aid with resolving GPS altitude input needs.

To use the ADS-B Out capability the transponders must be connected to an NMEA GPS. TRIG carries the Freeflight 1201 GPS for this function, but it is possible to use your own NMEA GPS.


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.