Trig TT23 and TT23G Class 1 Mode S Transponders with Built-in Altitude Encoder and optional built-in GPS

Note: Price does not include tariff. 

The TT23 and TT23G are a very interesting new transponders.  It is a Mode S transponder with a built-in altitude encoder, optional built-in GPS (TT23G version), and an optional TC20 remote display - at a great price! 

Description:
Simple to install, simple to use – The TT23 is the next generation of Trig’s compact Transponder line. 

The new design is smaller and lighter than its predecessors, reducing instrument panel space and weight while introducing advanced features for pilots worldwide. 

The TT23 is a fully certified Class 1, Mode S transponder with ADS-B Out, suitable for both VFR and IFR flight. Its compact form factor is ideal for aircraft with limited panel space, ensuring maximum efficiency without compromising performance. 

Features:

The transponder is available in two versions: 

• TT23G: Features a built-in, ETSO-C199 certified GPS receiver – the ideal choice for pilots seeking an integrated ADS-B out solution. The TT23G is perfect for experimental and light sport aircraft looking to meet the requirements for ADS-B out in the United States. In markets when ADS-B equipage is voluntary, the TT23G is the perfect solution for enhancing conspicuity and safety. 

• TT23: For aircraft with a suitable GPS position source on board, the TT23 (without GPS) can be used as an ADS-B solution. An STC will be available to integrate with popular 3rd party GPS navigators, as well as the Trig TN70 Remote position source. For those that do not intend to equip with ADS-B out, the TT23 model is a high-quality, modern transponder with easy configuration options that make it suitable for any application. that make it suitable for a broad range of GA applications.  

Product Design:

The TT23 and TT23G transponders are designed for easy installation. Both models are mounted remotely from the instrument panel, giving maximum flexibility on panel space and wiring. 

The transponder is controlled by the popular TC20 control head. Well-known for its compact size, this takes up minimal space and depth in the panel. The controller has a built-in altitude encoder, saving additional space and weight.  

The control head fits into a 57mm round hole, with the option of using a smaller compact mount hole. When fitted the depth of the controller is only 54mm, and connected to a wiring harness the depth is still only 85mm. 

The TT23 is compatible with a wide range of aircraft and avionics systems, ensuring flexibility and adaptability. 

Trig Transponder Example Systems
The link below takes you to a page with several complete Trig transponder example systems.
https://www.cumulus-soaring.com/store/trig-example-systems-transponders

Specifications:

• TT23 or TT23G Transponder Unit (main unit)
• TC20 Control Unit (User Interface)
• Mounting Tray for TT23 or TT23G transponder unit
• Adapter for mounting the TC20 in a 57 mm (2 1/4") instrument hole (with mounting screws)
  
• Mounting screws for mounting the TC20 without the use of the adapter for 57 mm instrument hole
• Pneumatic tubing for connection to static port (connects to TC20 Control Unit)
• Tee connector for pneumatic tubing
• 2 x Straight connector for pneumatic tubing
• DB-25 m Connector and backshell for TT23 or TT23G unit
• DB-9f Connector and backshell for TC20 unit
• Hose clamps for securing pneumatic tubing in aircraft
• TNC connector for transponder antenna (connects to TT23 or TT23G)
• Installation Manual
• Operating Manual

Not Included:

• Wiring harness for connecting TT23G to TC20 display and 12V power.  Wiring details are in the installation manual (see link below).  All connectors are included, but they are not wired together.  Pre-made wiring harnesses are available.  

Trig Flow Chart - Which GPS for ADS-B OUT for Experimental and non-Experimental Sailplanes
There are a lot of confusing rumors about which GPS to use to legally get ADS-B 1090 OUT in the USA.  In past years, if you had a experimental sailplane, or a Light Sport aircraft, you could use the Trig TT22 transponder with a TN72 GPS, but sailplanes certificated in the Standard Airworthiness category needed to use the much more expensive and much larger Trig TN70 GPS - and the huge TA70 GPS antenna.  Fortunately, in recent years, Trig has worked with the FAA and FCC to get approvals for using the lower cost TN72 GPS in sailplanes certificated in the Standard Airworthiness category - as long as the sailplane won't fly above 18,000 feet, or in Class B or C airspace, or over the Gulf of Mexico.  Please see the link below for a flow chart detailing how to select the correct GPS for your application.  Those restrictions aren't a problem for mail sailplane owners, so 99% of sailplane owners have installed the TN72 GPS in their sailplanes.  The new Trig TT23G with built-in GPS engine works in the same applications in which the TT22 and TN72 were used for previously.  
Trig - Which GPS for Glider.pdf - Note: It's 2 pages.

STC for TT22 with TN70 - And the TT23 and TN70 
If you have a sailplane certificated in the Standard Airworthiness category, and you need to fly in Class B or Class C airspace, or above 18.000 feet, or over the Gulf of Mexico, then you'll need to install the TT22 and TN70 and a Peregrine Airspeed Switch.  Peregrine owns the STC for the combination.  The STC documents are available upon request.  The new Trig TT23 is not on that STC, but Trig is working on that.  As of December of 2025, Trig has completed the flight testing phase of the TT23 STC.  They are optimistic that the STC will be completed in early 2026.  Until then, the TT22 and TN70 are the only legal solution.  Once the STC is completed, the use of the TT23 transponder with a TN70 GPS engine and TA70 GPS antenna and Peregrine Airspeed Switch will provide a fully approved system for all sailplane types and in all airspace.

Brochure and Manuals
TT23 and TT23G Brochure, Operating Manuals and Installation Manuals
https://trig-avionics.com/support/install-and-user-manuals/

Example Systems