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Sandia STX 165R ADS-B

R7237

Well Known Member
Finishing a build of an RV-7 that has a new Sandia STX-165R Mode C transponder. I would like to meet the 2020 mandate for ADS-B. Sandia website states it will be compliant with a “UAT 978”. I have tried figuring that out, but am running in circles between 1090, Mode S and 978, Mode C. What would I need to purchase in order to meet the 2020 mandate? Thanks in advance.

EFIS is an AFS 5600. Currently the GPS is not the 2020 version.
 
Finishing a build of an RV-7 that has a new Sandia STX-165R Mode C transponder. I would like to meet the 2020 mandate for ADS-B. Sandia website states it will be compliant with a “UAT 978”. I have tried figuring that out, but am running in circles between 1090, Mode S and 978, Mode C. What would I need to purchase in order to meet the 2020 mandate? Thanks in advance.

EFIS is an AFS 5600. Currently the GPS is not the 2020 version.

You sound confused. You’re not alone. To fly in airspace where adsb-out is required (over 10,000’, class B, C, or over B, C, within 30nm mode C veil around a class B airport) you must have an altitude reporting transponder (mode C or S) and an ADSB-out device. The out device can be the transponder itself (operating on 1090 MHz) if it’s a mode S-ES (ES stands for extended squitter-extra data that contains the adsb info) or it can be a Universal Access Transceiver (UAT) operating on 978 MHz. The adsb out device (SES transponder, or UAT) must be fed high quality gps data from a gps that is TSO’d for this, or which has a manufacturer’s statement that it meets the gps performance specs. Examples of the former would be Garmin’s 430W (must be WAAS version). Example of the latter would be gps offered by GRT for $500. You must be sure the gps can communicate with the adsb transmitter (some boxes use uncompatible formats). Finally, ADSB-in is not required by law - but you get no benefit unless you have an -in receiver. So, some suggestions:
1. Buy a compatible UAT. These usually have both transmitter and receiver. Buy an approved gps to feed it. Make sure they talk to each other. Make sure the receiver can talk to your AFS EFIS to display the data. Often you can buy the adsb transmitter, receiver, gps as a package.
2. Sell the 165, buy a Trig TT-22 mode S-ES transponder. Buy the GRT or other approved gps to feed the TT22 data. Buy a adsb-in box that works with your efis.
 
I paired that very STX-165 transponder with a Garmin GDL 82 ADS-B out in a Super Cub. The STX-165 is a great little digital transponder. They worked great together. However, best bang for the buck for an EAB aircraft would be to pair the STX unit with a uAvionix Echo ADS-B out. That works equally well with all the advantages of UAT like anonymous mode combined with ADS-B "in" at a lower price than the Garmin UAT unit. With both the Echo pre-packaged (kit with SkyFX external GPS) and GDL 82 unit there is an approved WAAS GPS source built-in so no external source is needed.

Jim
 
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I have the Sandia 165R in my RV4, paired with the GRT SafeFly 2020 compliant GPS and the uAvionix echo for ADS-B in/out. The echo mounts directly on the GPS unit, which mounts right on the back of my GRT EFIS. The 165 is controlled by the EFIS. I’m pretty sure your AFS EFIS will work the same way.you could get the uAvionics version of the GPS. It looks the same and I think it’s the same size. Same price too, at least it was last winter when I got mine.

923EFB13-6233-42CD-AD71-D5BF3E2CBBB7.jpg

The echo is the black unit, mounted directly on the SafeFly GPS, and in the pic, mounted to the back of my EFIS. You would probably have to mount those two separately, but they would talk to your EFIS and 165 through a similar harness.
 
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