Transponder installation article- Soaring Magazine

On Tuesday, December 15, 2020 at 5:56:09 PM UTC-8, wrote:
On Tuesday, December 15, 2020 at 1:34:24 PM UTC-5, Dan Marotta wrote:
On 12/15/20 10:15 AM, wrote:
On Tuesday, December 15, 2020 at 11:56:33 AM UTC-5, Dan Marotta wrote:
On 12/15/20 3:02 AM, wrote:
A few random notes from my TT22 installation:

- From the Trig Installation Manual: "The transponder power input is not protected against reversed power connections. Reversing the power and ground inputs to the transponder will destroy it. Check wiring before applying power."
-- A proven hazard demonstrated (luckily) by someone else

- Common sense for all transmitters but not obvious on a transponder: Make sure the antenna is connected before any transmission takes place. When is that? Generally, anytime the transponder is on GND, ON, or ALT switch mode and it gets and replies to an interrogation. SBY mode use (e.g., for initial TT21/22 SETUP programming) should be OK without having the antenna connected. But it's easy to mistakenly turn past SBY onto one of the "transmit" positions. So it's best to have the antenna connected before powering on.

- If you plan to have ADS-B Out by integrating a Trig TN70 or TN72, both the firmware on the TC20 control head AND the main transponder (TT21/22) must be of a certain version number or later (like v1.14 and v2.12, respectively). An authorized Trig dealer can confirm the current requirements and upgrade your firmware as needed.
-- The firmware versions are displayed very briefly on the control head screen after powering on. I video'd the sequence and replayed it several times to catch the numbers.

Good information about the firmware. I had to send the control head for
the TT22 in the Stemme to the avionics shop for upgrade. There was no
charge for the service IIRC.

--
Dan
5J
Thank you all for the help and information, as wel as the link to the original article. We're considering installing a trig22 with ADS-B out for or glider, which also happens to be a DG303 as in the article.
Thanks

If your DG303 is experimental, then get the TN72 GPS and TA50 antenna.
Those are what I installed in my gyro and they work perfectly. No need
to buy the gigantic TA70 antenna which is a pain to mount and costs a
bunch more. I mounted my TA50 antenna on the glare shield of the gyro
using the sticky back tape that came with it. It hasn't moved in 150
hours of flying plus ground ops.

--
Dan
5J
Yes, our 303 is experimental so the trig22 seems like the best way to go. I imagine we'll be also opting for the ADS-B option given the relatively low cost and ease to do so.

I had the ADS-B out option installed on my ASH31Mi using the TT22 and the TN72, and highly recommend it. You will be much more visible to both ATC and airliners with TCAS. A big bonus is the power consumption of this pair is very low. I only wish this was permitted for certificated gliders.

Tom

On Saturday, December 19, 2020 at 5:14:23 PM UTC-5, 2G wrote:
On Tuesday, December 15, 2020 at 5:56:09 PM UTC-8, wrote:
On Tuesday, December 15, 2020 at 1:34:24 PM UTC-5, Dan Marotta wrote:
On 12/15/20 10:15 AM, wrote:
On Tuesday, December 15, 2020 at 11:56:33 AM UTC-5, Dan Marotta wrote:
On 12/15/20 3:02 AM, wrote:
A few random notes from my TT22 installation:

- From the Trig Installation Manual: "The transponder power input is not protected against reversed power connections. Reversing the power and ground inputs to the transponder will destroy it. Check wiring before applying power."
-- A proven hazard demonstrated (luckily) by someone else

- Common sense for all transmitters but not obvious on a transponder: Make sure the antenna is connected before any transmission takes place.. When is that? Generally, anytime the transponder is on GND, ON, or ALT switch mode and it gets and replies to an interrogation. SBY mode use (e.g., for initial TT21/22 SETUP programming) should be OK without having the antenna connected. But it's easy to mistakenly turn past SBY onto one of the "transmit" positions. So it's best to have the antenna connected before powering on.

- If you plan to have ADS-B Out by integrating a Trig TN70 or TN72, both the firmware on the TC20 control head AND the main transponder (TT21/22) must be of a certain version number or later (like v1.14 and v2.12, respectively). An authorized Trig dealer can confirm the current requirements and upgrade your firmware as needed.
-- The firmware versions are displayed very briefly on the control head screen after powering on. I video'd the sequence and replayed it several times to catch the numbers.

Good information about the firmware. I had to send the control head for
the TT22 in the Stemme to the avionics shop for upgrade. There was no
charge for the service IIRC.

--
Dan
5J
Thank you all for the help and information, as wel as the link to the original article. We're considering installing a trig22 with ADS-B out for or glider, which also happens to be a DG303 as in the article.
Thanks

If your DG303 is experimental, then get the TN72 GPS and TA50 antenna..
Those are what I installed in my gyro and they work perfectly. No need
to buy the gigantic TA70 antenna which is a pain to mount and costs a
bunch more. I mounted my TA50 antenna on the glare shield of the gyro
using the sticky back tape that came with it. It hasn't moved in 150
hours of flying plus ground ops.

--
Dan
5J
Yes, our 303 is experimental so the trig22 seems like the best way to go. I imagine we'll be also opting for the ADS-B option given the relatively low cost and ease to do so.
I had the ADS-B out option installed on my ASH31Mi using the TT22 and the TN72, and highly recommend it. You will be much more visible to both ATC and airliners with TCAS. A big bonus is the power consumption of this pair is very low. I only wish this was permitted for certificated gliders.

Tom
Yes. I'm definitely interested in pursuing this... thanks for all the info and help.
Gregg. I'm sure I'll be in touch once the holidays settle down a little bit, this has been put on the backburner during the holidays. I always thought adding a transponder would be a good idea, but after a much more closer than comfortable encounter with another aircraft that I'm sure never saw me, it has become a priority. Adding the ADS-B out unit is in rhe plans as well.

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

Get the TT22. Don't consider the TT21. It could save you about $150 on a $2500 USD purchase but does not provide full ADS-B compliance. In the USA this means a TT21 does not allow you to fly in transponder-required airspace. The TT22 provides a full ADS-B out solution and more transmit power, yet its power consumption is identical to the TT21, according to Trig's spec sheets.

For an experimental glider you can use the same GPS receiver and antenna that you would find in a TT21 ADS-B out package (Trig TN72 and Trig TA50), so the only added cost is the $150 to upgrade to the TT22.

...david

On Monday, December 21, 2020 at 7:19:22 PM UTC-5, 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

On Monday, December 21, 2020 at 6:23:20 PM UTC-7, wrote:
Get the TT22. Don't consider the TT21. It could save you about $150 on a $2500 USD purchase but does not provide full ADS-B compliance. In the USA this means a TT21 does not allow you to fly in transponder-required airspace.. The TT22 provides a full ADS-B out solution and more transmit power, yet its power consumption is identical to the TT21, according to Trig's spec sheets.

For an experimental glider you can use the same GPS receiver and antenna that you would find in a TT21 ADS-B out package (Trig TN72 and Trig TA50), so the only added cost is the $150 to upgrade to the TT22.

...david
On Monday, December 21, 2020 at 7:19:22 PM UTC-5, 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
Fully agree a new purchase should be a TT22. Unfortunately, my glider has been setup with mode-S TT21 for some time now. I understand it costs ~$1000 or so to have an existing TT21 upgraded to TT22 specs. Since I can't see any practical need for my glider to have the 2x xmit power compliance, I'd like to save the $1000 and, perhaps, spend it in the future when the next wave of new transponder compliance requirements come about. I could always perform the upgrade later if that made sense for me.

thx, JJ

John Johnson wrote on 12/22/2020 10:38 AM:
On Monday, December 21, 2020 at 6:23:20 PM UTC-7, wrote:
Get the TT22. Don't consider the TT21. It could save you about $150 on a $2500 USD purchase but does not provide full ADS-B compliance. In the USA this means a TT21 does not allow you to fly in transponder-required airspace.. The TT22 provides a full ADS-B out solution and more transmit power, yet its power consumption is identical to the TT21, according to Trig's spec sheets.

For an experimental glider you can use the same GPS receiver and antenna that you would find in a TT21 ADS-B out package (Trig TN72 and Trig TA50), so the only added cost is the $150 to upgrade to the TT22.

...david
On Monday, December 21, 2020 at 7:19:22 PM UTC-5, 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
Fully agree a new purchase should be a TT22. Unfortunately, my glider has been setup with mode-S TT21 for some time now. I understand it costs ~$1000 or so to have an existing TT21 upgraded to TT22 specs. Since I can't see any practical need for my glider to have the 2x xmit power compliance, I'd like to save the $1000 and, perhaps, spend it in the future when the next wave of new transponder compliance requirements come about. I could always perform the upgrade later if that made sense for me.


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

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

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.