Transponder FAQ’s

How do I get a software upgrade?

Details of Trig software versions are shown on our product software page. Your Approved Trig Dealer can advise you if this will be of benefit to you.

Software upgrades may be introduced to add compatibility with third party products – if associated equipment is not installed in your aircraft then updating software is not usually required.

For software updates please contact your Approved Trig Dealer.

How can I tell what software version I am running?

Trig products will briefly display the software version(s) when initially powered up. See our product software page


What type of transponder antenna can I use?

Almost any transponder antenna can be used with any transponder. Various models are available based on the screw hole pattern desired and the speed/drag considerations for the aircraft type.

  • AV-22
  • CI-101 Stub type antenna examples
  • CI-105
  • AV-74 Blade type antenna examples

Ultimately, it is the responsibility of the installer or installing agency to determine what antenna is suitable for the aircraft application.

Where do I get a Mode S address / do I need a Mode S address?

Your Trig transponder will not operate until you enter a valid Mode S address.

Generally new aircraft will feature a Mode S address on their registration certificate. If you do not have a Mode S address, you will need to approach your national civilian airspace regulator who will issue your Mode S identifier.

Link for UK registered aircraft – G-INFO –

For N registered aircraft entering your tail number into the transponder settings will automatically generate your Mode S address.

Are there any adverse RF radiation effects from using a transponder?

Although Trig transponders can output a nominal power up to 260 Watts, the transmission is pulsed and has a duty cycle of about 0.55%.  This means that the effective radiation power is about 2 to 3 watts.

With an antenna more than 50cm away, plus the effects of the aircraft skin, ground planes, obstacles and basically not a direct path, the actual RF radiation reaching the cockpit is very low and considered no more of a risk to health than mobile phones.

Will Trig transponders display TIS-A on a GNS-530?

All Trig transponders can display TIS-A Traffic via a wide range of compatible avionics, via RS232. TT31 units shipped after May 2012 also support ARINC TIS-A. More information on compatibility can be found in relevant transponder installation and user documents.

Note – TIS-A is an older US traffic service only available in certain areas of the U.S. For TIS-B you will need a separate ADS-B In receiver.

Does my FAA aircraft need an STC to replace my transponder?

In the U.S. if you own a certified aircraft a simple logbook entry with field approval is all that is required.

If you wish to install a compliant ADS-B Out solution then in a certified aircraft an STC is required.

If in doubt, please consult your regulatory authority.

I need a Minor Change certificate but my aircraft is not listed on your website, what can I do?

The first thing to do is contact as we hold an unofficial database of Minor Changes held by our dealers and we may be able to put you in contact with someone that holds the Minor Change you are after.

Alternatively, CS-STAN can be used. Please find our CS-STAN guide here.