Author Topic: Wiring into Trig TT21 - is it worth it?  (Read 2899 times)

Altomar718

Wiring into Trig TT21 - is it worth it?
« on: November 25, 2020, 03:36:36 pm »
 Hi All

I have got the carry PAW and have read about fitting external antennas for ADBS out - I fly in Devon mostly so not so much traffic but do go on day trips - Question - is it worth wiring in to the Trig TT21 please

PaulSS

Re: Wiring into Trig TT21 - is it worth it?
« Reply #1 on: November 25, 2020, 04:43:35 pm »
In my opinion, yes. The cost of wiring to a TT21 is so low as to be irrelevant and will leave you with the best of both worlds. You'll have ADSB Out and the best option in terms of receiving all the other EC protocols, as well as METARs etc when in range of an ATOM station.

I have an external PAW antenna but my ADSB receiving antenna is mounted inside my (fabric covered) aircraft. Admittedly my TT21 gets its GPS information from my EFIS, instead of my PAW but if I didn't have that link then I would simply wire up the transponder to my Pilot Aware.

An FTDI cable and a couple of hours work and you're all set to see and be seen.

Ancien

Re: Wiring into Trig TT21 - is it worth it?
« Reply #2 on: November 25, 2020, 05:58:14 pm »
I agree with Paul. It certainly is worth it.
It's cheap and simple to do.
There will be other traffic out there not PAW equipped but with ADS-B in on another system so they will see you.
You don't need another antenna. You must have misread something.
Good luck.
Bob

steveu

Re: Wiring into Trig TT21 - is it worth it?
« Reply #3 on: November 25, 2020, 06:49:48 pm »
I think it's important to mention screening.

Certified stuff may screen out ADS-B from a source with uncertified GPS, i.e. SIL = 0. Or you may be seen but not trigger TCAS. So, you won't necessarily pop up on every ADS-B in system, and the CAA agrees with this conclusion, having echoed it in their EC grant application backgrounder.

This is a point worth raising but does not alter the advice given to make the connection with the cable, set up the TT21 as per the Trig instructions, and enjoy the benefits of being seen by more aircraft.

tnowak

Re: Wiring into Trig TT21 - is it worth it?
« Reply #4 on: November 26, 2020, 07:08:50 am »
My understanding is that TCAS in CAT is triggered by the other aircraft's transponder and not its ADS-B Out data.
Future upgrades in TCAS technology may process ADS-B Out data for TCAS purposes, but will always process transponder data from your certified Trig TT21.
As other posters have said, definitely go ahead and make yourself ADS-B Out visible.
Tony

Altomar718

Re: Wiring into Trig TT21 - is it worth it?
« Reply #5 on: November 26, 2020, 09:05:34 am »
This is available on the PAW website, hence my comment about external antennas :- https://www.pilotaware.com/product/aviation-grade-external-antennas

I agree with Paul. It certainly is worth it.
It's cheap and simple to do.
There will be other traffic out there not PAW equipped but with ADS-B in on another system so they will see you.
You don't need another antenna. You must have misread something.
Good luck.
Bob

exfirepro

Re: Wiring into Trig TT21 - is it worth it?
« Reply #6 on: November 26, 2020, 10:29:58 am »
Hi Altomar,

You don’t say what type of aircraft you fly. The external antennas are of significant benefit if the aircraft is metal-bodied as they get the signal out in the clear away from potential obscuration.

I have also been using them under the pod of my flexwing (with a thin laminated aluminium foil ground plane inside the pod) for some time now to very good effect - especially the 869.5 MHz P3i one. If using both, be careful to keep the shorter 1090MHz one as far away from your transponder antenna as practicable to avoid potential interference (not so easy in a flexwing).

I also echo the others’ comments re connecting to your transponder. It’s a fairly simple and inexpensive job, using a single USB to RS232 Serial Adapter Cable (obtainable from RS Components or Farnell for under £30), and ensures that you will comply fully with the CAA recommendation that we all ‘transmit ADSB on 1090MHz’, so is in my opinion a ‘no-brainer’. If you need any help or advice, feel free to ask - I have done several.

Regards

Peter

steveu

Re: Wiring into Trig TT21 - is it worth it?
« Reply #7 on: November 26, 2020, 11:01:07 am »
My understanding is that TCAS in CAT is triggered by the other aircraft's transponder and not its ADS-B Out data.
Future upgrades in TCAS technology may process ADS-B Out data for TCAS purposes, but will always process transponder data from your certified Trig TT21.
As other posters have said, definitely go ahead and make yourself ADS-B Out visible.

You're right, brain fart on my part as TCAS interrogates the transponders around it...

Altomar718

Re: Wiring into Trig TT21 - is it worth it?
« Reply #8 on: November 26, 2020, 11:20:12 pm »
Hi Peter

Thanks for that - I have got a little Eurostar .......

Chris

Hi Altomar,

You don’t say what type of aircraft you fly. The external antennas are of significant benefit if the aircraft is metal-bodied as they get the signal out in the clear away from potential obscuration.

I have also been using them under the pod of my flexwing (with a thin laminated aluminium foil ground plane inside the pod) for some time now to very good effect - especially the 869.5 MHz P3i one. If using both, be careful to keep the shorter 1090MHz one as far away from your transponder antenna as practicable to avoid potential interference (not so easy in a flexwing).

I also echo the others’ comments re connecting to your transponder. It’s a fairly simple and inexpensive job, using a single USB to RS232 Serial Adapter Cable (obtainable from RS Components or Farnell for under £30), and ensures that you will comply fully with the CAA recommendation that we all ‘transmit ADSB on 1090MHz’, so is in my opinion a ‘no-brainer’. If you need any help or advice, feel free to ask - I have done several.

Regards

Peter

exfirepro

Re: Wiring into Trig TT21 - is it worth it?
« Reply #9 on: November 27, 2020, 08:42:40 am »
Morning Chris,

There are lots of Eurostar Owners with permanent fits of PilotAware. IIRC from posts on the 'EV-97 Eurostar Forum' over on Facebook, there are a couple of 'redundant jig holes' underneath the aircraft near the wing roots which are ideally positioned to take the external antennas and which the relevant authorities have already agreed you can drill out to size for this purpose. Several well known Eurostar Owner/Users (including Paul D Kiddell) have posted comprehensive info on PilotAware fits over on Facebook recently and there is a wealth of information available. Definitely worth a search of their Forum and they are very amenable to requests for advice.

Best Regards

Peter