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Trig TT31 coupled with Garmin 430/530W


I’m wondering if anyone could help on this matter, I have a Trig tt31 Mode-S Xponder ( ADS-B out Ready as they say ) but its not ads-b due to lack of GPS positioning.

I want to enable what is called extended squitter and hook up my GNS430W to provide a true ADS-B output.

The Trig manual is very vague about this, there are pinouts and diagrams, but what I’m looking is real world experience, has any one here done it themselves?

I will tackle the matter in the next few days, but It would be handy if anyone here has any tips!

Thanks In Advance


I am doing this on a TT31 but with the Trig TN72 certified position source. However I looked into connecting the PowerFlarm Core into the TT31 a few years ago.

An Avionics shop did this for me but from what I remember it is a pair of wires, then you need to go into a service menu of the TT31 and select the integrity of the position source ie: SIL 1 . I didn’t do it for the PowerFlarm as it would have had a lower level integrity source and it would have been ignored by most anti collision devices.

One thing to be aware of. Is your TN72 sitting in a proper Trig tray as it has been slid into an original King transponder tray, it won’t have the extra serial socket on the back to connect the GPS source to. I had to swap my tray.

United Kingdom

We did this some time ago- it was a matter of connecting a couple of wires and replacing the BK tray that the installer couldnt be arsed to change when he did the first installation. We do find that we get an error message No ADSB Out unless we have a destination – any waypoint will do – in the 430

EHLE / Lelystad, Netherlands, Netherlands

Thanks for the advice.

Good to know about the tray, as we also used a slide in option from the old Bendix.

I did look into TN70/72 aswell, but as we have a certified Waas Garmin unit, this is not required I believe.

I will report when I get it fitted.



Peregrine has partnered with Trig and provides an STC for the GNS430W as a position source connected to the Trig TT31. As I understand it the STC is no charge. The STC uses an airspeed switch to determine ground/air status and they sell the switch separately. See


Did this a couple of years ago using gtn 650 (gns would be the same) Used trig stc via peregrine, which includes a neat air ground switch(airspeed based static/pitot) for txpr, saves switching prior to take off.
Have you talked to trig? I found them very helpful!


@evo400, if you have an EASA aircraft, you can connect a GNS430W to a TT31 for ADS-B out without an STC. There is a Standard Change that permits this if the transponder manufacturer states that the GPS-transponder combination is compliant and the TT31 installation manual does state this for the GNS430W.

ESKC (Uppsala/Sundbro), Sweden
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