Installing a transponder and ADS-B, Instructions?

I'm looking to buy an airplane and many of the experimental I am looking at do not have transponders or ADS-B (unsurprising). I live in a Mode C veil, so a transponder (and, in a year ADS-B) will be required. I have an extensive electronics background, but I have not worked on airplanes.

As I evaluate airplanes, I would like to know what I need to do to install a Transponder in an experimental. I am not too worried about installing ABS-B on something with a transponder (because of the uAvionics Skybecon), but I cannot find information on installing a transponder from scratch. Does anyone know a link to instructions or an install video to install a transponder/encoder on a plane that has not had one before?

Hi, This;

While I don't have either a link to, or the actual instructions, I installed my own transponder in my homebuilt in 2012. It was a microair 2.25" unit. I thought it was simple and straightforward.

Just connected a data cable from my EFIS to the transponder so the altitude could be provided (along with power) and then antenna cable to a standard rod antenna on the belly.

Since I'm also under a Mode C veil, I had the local instrument shop guy come to the hangar to do the biennial transponder cert to ensure what the pitot was sensing was what the transponder was reporting.

I'll install my own on my current build project as well, albeit with ADS-B out, which requires just a bit more stuff like having a WAAS GPS source. Still haven't decided which solution to use in this instance. Still waiting for the $1000 ADS-B transponder in a box solution. ;-)

Intstall transponder. Install antenna. Install an altitude encoder (usually a blind encoder). Connect the wires then spend some quality time with an avionics shop for an Appendix E/F check

I recently replaced the old Terra Transponder in one of my planes with a Sandia Aerospace STX-165. It has the encoder integral to the transponder, so you install power, ground, antenna, and connect a hose to the static port. That's it, unless you add in the overpriced OAT probe. Fits either a 3-1/8 round instrument hole, or can be adapted to fit half width in a standard transponder mounting hole, or custom cut your panel to fit.

After installation, you need to swing by a radio shop to have the transponder tested for output, frequency and correct altitude reporting. (regular transponder cert).

The STX165 does give you the option of running a cable to your EFIS to supply it with pressure altitude, or to plug into separate encoder if you want (EFIS Supplying pressure Altitude).

-Cub Builder

Quote:

---

Originally Posted by thisadviceisworthles

I. Does anyone know a link to instructions or an install video to install a transponder/encoder on a plane that has not had one before?

---

AC 43.13-2B - Acceptable Methods, Techniques, and Practices - Aircraft Alterations

Probably not a lot of discussion because it's stone simple. Hookup power, ground and maybe a wire to the dimmer bus. Connect the antenna and you're done. It's a radio, but there's no audio in/out, so way simpler than a comm. The altitude encoder is nine wires (usually labeled A1, A2, A4, B1, B2, B4, C1, C2, C4) that go from the encoder straight to the corresponding terminals on the transponder. Here's a typical schematic:

Attachment 7619

Quote:

---

Originally Posted by camorton

Probably not a lot of discussion because it's stone simple. Hookup power, ground and maybe a wire to the dimmer bus. Connect the antenna and you're done. It's a radio, but there's no audio in/out, so way simpler than a comm. The altitude encoder is nine wires (usually labeled A1, A2, A4, B1, B2, B4, C1, C2, C4) that go from the encoder straight to the corresponding terminals on the transponder. Here's a typical schematic:

---

The newer digital transponders and encoders are even easier to hook up than that.......only one serial data wire needed to connect the altitude encoder to the transponder instead of all those gray code connections. Gray code equipment still works but is now very old school. :)

Thanks for all of the information. It's good to know that a lack of a transponder is not a dealbreaker. Now I just need to find something with the useable load I want, that is in my price range.

Well the good news is now lots of people are installing ADS-B, so there's a huge glut of older (but still functional) mode A/C transponders on the market. The economics of installing one are questionable since you'll still need to add ADS-B out by 2020, but it's an option if you're on a super tight budget. Cheaper UATs may still hit the market.

C.

It is my understanding that ADS-B OUT can be installed & certified by a part 145 shop, only.

Quote:

---

Originally Posted by crusty old aviator

It is my understanding that ADS-B OUT can be installed & certified by a part 145 shop, only.

---

That is not the case for aircraft with an experimental airworthiness certificate.

I have the installation/operation manual for my Artex 345 ELT in a pdf file. I'll send it to you if you want to take a look at it. It was not difficult to install. Even I could do it. There are a few photos in the Electrical section of my build log. Send me a PM if you want the manual.

Quote:

---

Originally Posted by Tralika

I have the installation/operation manual for my Artex 345 ELT in a pdf file. I'll send it to you if you want to take a look at it. It was not difficult to install. Even I could do it. There are a few photos in the Electrical section of my build log. Send me a PM if you want the manual.

---

This thread is about ADS-B transponders, not ELT's......

Quote:

---

Originally Posted by crusty old aviator

It is my understanding that ADS-B OUT can be installed & certified by a part 145 shop, only.

---

Not so, and not just for experimentals. An FAA policy memo dated 3/2/16 clarified that properly certified Out units can be installed as minor or major alterations depending on complexity. My A&P IA did mine and it was completely legal.

Quote:

---

Originally Posted by crusty old aviator

It is my understanding that ADS-B OUT can be installed & certified by a part 145 shop, only.

---

That is not true. I just installed a Garmin ADS-B out system in my experimental plane and got it approved with no problems. Of course, if your plane is certificated, that is a different matter.