Is my funke TRT800 working correctly?

[Chris7777]

I have two Pilotawares, one set as a base station and one in my aircraft, both have different IDs. My friend has a Trig mode S transponder and if it is turned on, even in the hanger I can pick it up on my PAW. I think this is because "Mode S Transponders ... broadcast in unsolicited “SQUITTER” transmissions  ... approximately every second." (Is that correct?) So they do not need to be interrogated to be picked up by PAW.

I have funke TRT800 mode S transponder, software v5.2, but I can't pick it up, on the ground, on my base PAW. However I can see myself on Flightradar24 if I am flying above 3000' (I am in a hilly area).

The transponder has recently been back to funke for repair. My question is my mode S transponder working correctly because it does not seem to work as well, or in the same way, as the Trig.

[tnowak]

Chris,

Yes, you are correct in that Mode S transponders will transmit data every few seconds even if not interrogated.

From what you have described then I would say there is, probably, some kind of issue with your TRT800, coax cable or transponder antenna.

Have you tried taking your base station to where you keep your aircraft to see what you get?

Tony

[Paul_Sengupta]

This is ADS-B or non-ADS-B by the sounds of it. "Mode-S" needs an interrogation by radar, and the resulting reply will only appear on the PAW as a bearingless target. If the transponder has ES (Extended Squitter) and is capable of ADS-B-out, and has a GPS connected, and the GPS is giving out a valid position, then the transponder will send out the ES part on its own without interrogation. This will include GPS co-ordinates which will give you can absolute position on the PAW, just like it will seeing another PAW.

FlightRadar24 has two modes of operation, it can either pick up the ADS-B information and display the aircraft position, or it can try and triangulate on transponder responses from several receivers, known as multi-lateration, shown as "MLAT" as the receiving station. This will be an approximate position.

I believe the TRT800 is capable of transmitting ADS-B if a suitable GPS is connected (and the PAW can be the suitable GPS).

[Chris7777]

Yes Tony new Aircell 7 coax and new aerial. Ok Paul. Thanks for your detailed explanation off ES and FR24. Plenty of food for thought. My TRT800 can do ADS-B but the software v5.2 has a fault with heading being always north. (See a different thread) But I have had it connected up on the ground. I'll try it again on the ground with the bad station at airport just to see what happens even though I can't fly it like that. Thanks for replies. Grateful for for increased under standing Chris