How do I tell if my GPS A20 it talking with my 23ES transponder?

Ok - dumb question. I have a Garmin G3X system and a GDL-39. I've had ADSB in for a while, but just installed a GPS A20 to get ADSB out.

FYI - the A20 is only hooked up to the 23ES transponder (I'm not using it as a GPS source for the G3X).

I am getting a solid green light on the A20, but is there anyway I can tell that the 23ES is getting the GPS signal? Is there any configuration I need to change in the G3X steup menu for the 23ES?

I am hoping not to have to put the plane back together, test it, then take it apart again if something is amiss.

Thanks,
Jason

Go fly the plane, then go to FAA website and request an ADS-B performance report, fill in the required info and submit. You should receive a detailed report back in about 10 minutes. If there are no red boxes, then the Fed's are happy. If there is a problem, I'm told the FAA will likely be in touch to inform you there is a problem that needs to be corrected.

I plan to fly it this weekend and see what the FAA report looks like, but I was hoping to find a way to make sure the 23ES was receiving the GPS signal before I spent an hour or more putting the plane back to flyable condition... then only to find it's not working and to have to take it a part again.....

UnPossible said:

Ok - dumb question. I have a Garmin G3X system and a GDL-39. I've had ADSB in for a while, but just installed a GPS A20 to get ADSB out.

FYI - the A20 is only hooked up to the 23ES transponder (I'm not using it as a GPS source for the G3X).

I am getting a solid green light on the A20, but is there anyway I can tell that the 23ES is getting the GPS signal? Is there any configuration I need to change in the G3X steup menu for the 23ES?

I am hoping not to have to put the plane back together, test it, then take it apart again if something is amiss.

Thanks,
Jason

Click to expand...

Hello Jason,

The transponder control area at the top of your G3X Touch display will display "NO ADSB" if the transponder is telling the system that it is not capable of performing the ADS-B Out function.

If you power up your system with everything on but the GPS 20A position source, confirm that the yellow "NO ADSB" annunciation is shown in the transponder control area, then power-up the GPS 20A and confirm that this annunciation is removed after the GPS 20A gets a good fix, that is pretty good confirmation that your GTX 23ES is getting ADS-B+ data from the GPS 20A.

Thanks,
Steve

g3xpert said:

Hello Jason,

The transponder control area at the top of your G3X Touch display will display "NO ADSB" if the transponder is telling the system that it is not capable of performing the ADS-B Out function.

If you power up your system with everything on but the GPS 20A position source, confirm that the yellow "NO ADSB" annunciation is shown in the transponder control area, then power-up the GPS 20A and confirm that this annunciation is removed after the GPS 20A gets a good fix, that is pretty good confirmation that your GTX 23ES is getting ADS-B+ data from the GPS 20A.

Thanks,
Steve

Click to expand...

I am seeing the "NO ADSB" annunciation whether or not the 20A is powered up or not.

I am seeing a solid green light on the 20A. I've double checked the wiring and it all looks good. Is there any sort of setup or configuration I need to do?

Do I need to be in the air, or near an ADSB station to get the "No ADSB" alert to go away?

Thanks,
Jason

UnPossible said:

I am seeing the "NO ADSB" annunciation whether or not the 20A is powered up or not.

I am seeing a solid green light on the 20A. I've double checked the wiring and it all looks good. Is there any sort of setup or configuration I need to do?

Do I need to be in the air, or near an ADSB station to get the "No ADSB" alert to go away?

Thanks,
Jason

Click to expand...

Hello Jason,

When you configure your G3X Touch system to have a GTX 23ES it will automatically configure the GTX 23ES RS-232 #2 input for ADS-B+, so you shouldn't have to configure anything.

Page 27-23 of the Rev. AE G3X Installation Manual shows how to wire the GPS 20A to the GTX 23ES.

No, you do not need to be in the air or near an ADS-B station. An ADS-B out system couldn't care less if you are near a ground station.

Just as soon as the GPS status LED on the GPS 20A stops flashing, and goes to a steady solid green, the NO ADSB annunciation should clear.

Note that there are two status LEDs on the GPS 20A, so make sure you are looking at the GPS status LED.

The unit status LED between the two connectors should also be solid green when not installed on the CAN bus.

You should ideally be using V8.02 or later software on your transponder, but V7.00 and newer should work.

Thanks,
Steve

g3xpert said:

Hello Jason,

Just as soon as the GPS status LED on the GPS 20A stops flashing, and goes to a steady solid green, the NO ADSB annunciation should clear.

Thanks,
Steve

Click to expand...

How long should it take for the GPS status light to go solid green? I checked after a couple of minutes (with the plane pulled out of the hangar), and it was still flashing - about 1/ second... not sure if that is fast or slow.

Thanks for all your help,
Jason

UnPossible said:

How long should it take for the GPS status light to go solid green? I checked after a couple of minutes (with the plane pulled out of the hangar), and it was still flashing - about 1/ second... not sure if that is fast or slow.

Thanks for all your help,
Jason

Click to expand...

Hello Jason,

My experience has been that it typically receives a full fix and turns off the "NO ADSB" annunciation in about 1 minute or less.

Too bad you don't have the CAN bus connected to the GPS 20A. If you did, you would be able to see the GPS status page with signal strength bars.

It sounds like it was still flashing slowly.

You might think about contacting us directly for more efficient support.

Thanks,
Steve

Just to close this out in case someone searches for this in the future.

I called and spoke with Garmin this morning and learned that the first time the GPS A20 acquires the satellites it can take 5-10 minutes to lock on. I had only been waiting a couple of minutes before giving up.

I pulled my plane out of the hangar, turned it all on and waited 5-6 minutes, and bingo, two solid green lights and the "No ADSB" warning was gone.

I turned off the GPS A20 and the "No ADSB" warning popped right up. Turned it back on and 60-90 seconds later it was gone.

So best I can tell everything is working correctly.... now to fly and see if the FAA ADSB report agrees.

Thanks,
Jason