Transponder installation article- Soaring Magazine

On Tuesday, December 22, 2020 at 11:56:51 AM UTC-7, Eric Greenwell wrote:
I suggest you keep your TT21, but install a TN72 with a TA50 antenna (total equipment cost of
about $460). You can't use it to enter A, B, and C airspace, though there are probably some
exceptions for glider operating areas (and maybe others), but you otherwise have all the
features the TT22 would give you. Here's the Trig document for gliders:

https://www.trig-avionics.com/librar...ust%202018.pdf


Thanks Eric. I think I will take this route. I received a few PM's from pilots using TT21's in this fashion. It makes a lot of sense for the case where you already have a TT21 and don't see a need to fly in full compliance airspace. I installed a PowerMouse with ADS-B in this year and it's helped me see just how busy the (unseen) traffic is in the Arizona airspace I mostly fly in. I'll start working on the firmware update my older unit almost certainly needs to get it working properly with a TN72.

JJ

On 12/21/20 5:19 PM, John Johnson wrote:
Should I assume it is not legal in the US to use a TT21 with a TN72 for ADS-B out in an experimental glider? That combination is ok in Europe (I think) with the difference being the US wants 2x the xmit power for ADS-B (TT22 at 250W) vs the 125W output of the TT21. I would like to think that having otherwise compliant, lower power ADS-B out is better (and not illegal) than no ADS-B out in an aircraft that is legal without ADS-B.
Probably not a realistic hope - but it would save me the not trivial expense of upgrading my TT21 to a TT22.

JJ


I don't see why you couldn't use the TT21, but the price difference
between the TT22 and the TT21 is only $157. Why wouldn't you go for the
higher power and legality above 15,000'?

Rather than upgrade, why not sell the 21 and buy a 22?

--
Dan
5J

On Wednesday, December 23, 2020 at 12:11:12 PM UTC-7, Dan Marotta wrote:
On 12/21/20 5:19 PM, John Johnson wrote:
Should I assume it is not legal in the US to use a TT21 with a TN72 for ADS-B out in an experimental glider? That combination is ok in Europe (I think) with the difference being the US wants 2x the xmit power for ADS-B (TT22 at 250W) vs the 125W output of the TT21. I would like to think that having otherwise compliant, lower power ADS-B out is better (and not illegal) than no ADS-B out in an aircraft that is legal without ADS-B.
Probably not a realistic hope - but it would save me the not trivial expense of upgrading my TT21 to a TT22.

JJ

I don't see why you couldn't use the TT21, but the price difference
between the TT22 and the TT21 is only $157. Why wouldn't you go for the
higher power and legality above 15,000'?

Rather than upgrade, why not sell the 21 and buy a 22?

--
Dan
5J
Dan, I suspect the cost to replace my TT21 with a TT22 is a lot more than $200 - probably closer to a $1000. Since I can legally use my TT21 for ADS-B out everywhere I fly (and I can always upgrade to a TT22 later for no additional cost penalty), I'm not sure what I gain. As near as I can tell, I'll essentially have the same ADS-B out visibility and be experimental glider legal everywhere I fly. I do appreciate the advice.
In the meantime, if anyone is looking for a used TT21, let me know and I'll consider your offer.
JJ

On Wednesday, December 23, 2020 at 8:49:56 PM UTC-5, John Johnson wrote:
On Wednesday, December 23, 2020 at 12:11:12 PM UTC-7, Dan Marotta wrote:
On 12/21/20 5:19 PM, John Johnson wrote:
Should I assume it is not legal in the US to use a TT21 with a TN72 for ADS-B out in an experimental glider? That combination is ok in Europe (I think) with the difference being the US wants 2x the xmit power for ADS-B (TT22 at 250W) vs the 125W output of the TT21. I would like to think that having otherwise compliant, lower power ADS-B out is better (and not illegal) than no ADS-B out in an aircraft that is legal without ADS-B.
Probably not a realistic hope - but it would save me the not trivial expense of upgrading my TT21 to a TT22.

JJ

I don't see why you couldn't use the TT21, but the price difference
between the TT22 and the TT21 is only $157. Why wouldn't you go for the
higher power and legality above 15,000'?

Rather than upgrade, why not sell the 21 and buy a 22?

--
Dan
5J
Dan, I suspect the cost to replace my TT21 with a TT22 is a lot more than $200 - probably closer to a $1000. Since I can legally use my TT21 for ADS-B out everywhere I fly (and I can always upgrade to a TT22 later for no additional cost penalty), I'm not sure what I gain. As near as I can tell, I'll essentially have the same ADS-B out visibility and be experimental glider legal everywhere I fly. I do appreciate the advice.
In the meantime, if anyone is looking for a used TT21, let me know and I'll consider your offer.
JJ
The 21 can be upgraded to a 22 by Mid Continent and then you can add the TN 72 as the ADS B out. Don't know today's price for the conversion, but when I did it a year ago, it was very reasonable.

On Thursday, December 24, 2020 at 7:01:44 AM UTC-8, wrote:
On Wednesday, December 23, 2020 at 8:49:56 PM UTC-5, John Johnson wrote:
On Wednesday, December 23, 2020 at 12:11:12 PM UTC-7, Dan Marotta wrote:
On 12/21/20 5:19 PM, John Johnson wrote:
Should I assume it is not legal in the US to use a TT21 with a TN72 for ADS-B out in an experimental glider? That combination is ok in Europe (I think) with the difference being the US wants 2x the xmit power for ADS-B (TT22 at 250W) vs the 125W output of the TT21. I would like to think that having otherwise compliant, lower power ADS-B out is better (and not illegal) than no ADS-B out in an aircraft that is legal without ADS-B.
Probably not a realistic hope - but it would save me the not trivial expense of upgrading my TT21 to a TT22.

JJ

I don't see why you couldn't use the TT21, but the price difference
between the TT22 and the TT21 is only $157. Why wouldn't you go for the
higher power and legality above 15,000'?

Rather than upgrade, why not sell the 21 and buy a 22?

--
Dan
5J
Dan, I suspect the cost to replace my TT21 with a TT22 is a lot more than $200 - probably closer to a $1000. Since I can legally use my TT21 for ADS-B out everywhere I fly (and I can always upgrade to a TT22 later for no additional cost penalty), I'm not sure what I gain. As near as I can tell, I'll essentially have the same ADS-B out visibility and be experimental glider legal everywhere I fly. I do appreciate the advice.
In the meantime, if anyone is looking for a used TT21, let me know and I'll consider your offer.
JJ
The 21 can be upgraded to a 22 by Mid Continent and then you can add the TN 72 as the ADS B out. Don't know today's price for the conversion, but when I did it a year ago, it was very reasonable.


I believe the price is $900 TT21 to TN72

They will update the software in the TC20 & TT22/TT21 for free you pay the shipping then you could use the TT21 for a TABS installation.

http://www.craggyaero.com/transponder.htm

Richard
www.craggyaero.com

Been following this thread, as my glider has a TT21, and not sure what else is connected to it (TN72 GPS?). If I understand correctly, with the TT21 I cannot fly in A, B, and C airspace, but okay to fly in the rest, correct?

Thanks,
Paul

On 12/23/20 6:49 PM, John Johnson wrote:
On Wednesday, December 23, 2020 at 12:11:12 PM UTC-7, Dan Marotta wrote:
On 12/21/20 5:19 PM, John Johnson wrote:
Should I assume it is not legal in the US to use a TT21 with a TN72 for ADS-B out in an experimental glider? That combination is ok in Europe (I think) with the difference being the US wants 2x the xmit power for ADS-B (TT22 at 250W) vs the 125W output of the TT21. I would like to think that having otherwise compliant, lower power ADS-B out is better (and not illegal) than no ADS-B out in an aircraft that is legal without ADS-B.
Probably not a realistic hope - but it would save me the not trivial expense of upgrading my TT21 to a TT22.

JJ

I don't see why you couldn't use the TT21, but the price difference
between the TT22 and the TT21 is only $157. Why wouldn't you go for the
higher power and legality above 15,000'?

Rather than upgrade, why not sell the 21 and buy a 22?

--
Dan
5J
Dan, I suspect the cost to replace my TT21 with a TT22 is a lot more than $200 - probably closer to a $1000. Since I can legally use my TT21 for ADS-B out everywhere I fly (and I can always upgrade to a TT22 later for no additional cost penalty), I'm not sure what I gain. As near as I can tell, I'll essentially have the same ADS-B out visibility and be experimental glider legal everywhere I fly. I do appreciate the advice.
In the meantime, if anyone is looking for a used TT21, let me know and I'll consider your offer.
JJ

Hi John,

When I posted I missed the part where you already had a TT21. I thought
you were starting from scratch and so the extra $157 for a TT22 wouldn't
have been that much extra.

--
Dan
5J

On 12/24/20 11:07 AM, paul.fer....gmail.com wrote:
Been following this thread, as my glider has a TT21, and not sure what else is connected to it (TN72 GPS?). If I understand correctly, with the TT21 I cannot fly in A, B, and C airspace, but okay to fly in the rest, correct?

Thanks,
Paul



Not legal above 15K, but I've heard rumors it's been done.

On Thursday, December 24, 2020 at 10:07:36 AM UTC-8, paul.fer....gmail.com wrote:
Been following this thread, as my glider has a TT21, and not sure what else is connected to it (TN72 GPS?). If I understand correctly, with the TT21 I cannot fly in A, B, and C airspace, but okay to fly in the rest, correct?

Thanks,
Paul

Not only can't you fly IN those airspaces, you can't fly OVER them either, which may be the bigger limitation. Going back to Minden from the north the shortest distance may be over the Reno class C airspace, which only goes up to 8,400 ft. But you will need to be in compliance with class C airspace to even over-fly this airspace. The non-compliant aircraft will either have to get a waiver from ATC or fly 20 nm either east or west to avoid it altogether. Never mind that this might put you into conflict with air traffic flying in and out of Reno.

Tom

On 12/25/20 11:53 PM, 2G wrote:
On Thursday, December 24, 2020 at 10:07:36 AM UTC-8, paul.fer....gmail.com wrote:
Been following this thread, as my glider has a TT21, and not sure what else is connected to it (TN72 GPS?). If I understand correctly, with the TT21 I cannot fly in A, B, and C airspace, but okay to fly in the rest, correct?

Thanks,
Paul

Not only can't you fly IN those airspaces, you can't fly OVER them either, which may be the bigger limitation. Going back to Minden from the north the shortest distance may be over the Reno class C airspace, which only goes up to 8,400 ft. But you will need to be in compliance with class C airspace to even over-fly this airspace. The non-compliant aircraft will either have to get a waiver from ATC or fly 20 nm either east or west to avoid it altogether. Never mind that this might put you into conflict with air traffic flying in and out of Reno.

Tom



But aren't gliders exempt from the ADS-B rules? Or is a non-equipped
glider not allowed to fly over the top of the airspace?

I'm equipped, BTW.

--
Dan
5J