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Loss of GPS and ADSB

Witkin

I'm New Here
I am flying an RV-12 with a Dynon HDX. I am not the builder so my understanding of the systems is not great. There is a Dynon 2020 GPS antenna.

I get a warning that the ADSB HAS FAILED AND LOSS OF GPS.

Has anyone else had this happen and where do I begin to correct it?

ALAN

Actual message “POSITION SOURCE 1 FAIL
NO ADS-B OUT. GPS LOST
 

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Dynon tech support….. your ADSB failed due to gps failed. Fix gps, ADSB fixed! Happens often, once? Next time power off failed system, power back up, see if it comes back online. Make sure you did nothing like cover up antenna temporarily with anything if puck is in cockpit, and possibly eg: chart, checklist etc.

Good luck
 
Any military activity causing GPS interference in your area??
If not, then the GPS antenna might be defective.
 
Check wires at base of GPS puck antenna. Mounting holes are such that wires do not pass thru center of clearance hole. We noticed cut/frayed wires on Synergy built RV-12.
 
Always check wiring and connections first -- its the simplest and cheapest way to trouble-shoot. Wiggling the suspect wire/connection and watching for any instrument reading change is often a useful technique. All of the previous commentators' suggestions are valid as well.

Van's RV-12 plans and wiring diagram and Dynon's various manuals (https://www.dynonavionics.com/skyview-documentation.php) can aid you in tracing the circuit.
 
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I had the same problem. Opened the hole for the GPS antenna mount and freed up the wires going into the puck antenna. So far no further issues.
 
It appears you are on the ground and the issue could be antenna shading by something like a hangar. I see this error often when running my SV-D1000 if the aircraft is in the hangar with the door open all the way. I can see the sky but apparently the GPS antenna cannot see enough SVs to resolve a fix. Same problem with my other two GPS units, goes away as soon the aircraft is in the open.

If you see it flying or during taxi, start with wiring as others advised.

John Salak
RV-12 N896HS
 
Am I the only one who noticed something

I am flying an RV-12 with a Dynon HDX. I am not the builder so my understanding of the systems is not great. There is a Dynon 2020 GPS antenna.

I get a warning that the ADSB HAS FAILED AND LOSS OF GPS.

Has anyone else had this happen and where do I begin to correct it?

ALAN

Actual message “POSITION SOURCE 1 FAIL
NO ADS-B OUT. GPS LOST

Alan,

You have a position source. Your SkyView has a position as you have synthetic vision displayed. If you have a total GPS position failure, you would not have it.

First, do you have another GPS feeding it like a Garmin, Avidyne, or a GPS-250 puck? You need to determine what is your POS 1 source is and what is giving you the position for the synthetic vision. These are all in settings if you know where to look. Your synthetic vision source might be a POS 2 source or a GPS 1 source. Also what is your setting for the position source in the transponder settings.

Input Function Considerations and Priorities

SkyView's Moving Map Page uses POS and GPS sources for its data. Regardless of the number of data sources in your system, this page prioritizes these sources and fails over to them as follows:

POS 1, GPS 1, GPS 2, GPS 3, GPS 4, POS 2, POS 3, POS 4

For example, if your system has one SV-GPS-2020 configured as POS 1 and a Garmin 396 configured as GPS 1, the Moving Map will always use the SV-GPS-2020 as its primary data source. If the SV-GPS-2020 fails or you configure its input function to NONE, the Moving Map Page will use the Garmin 396 (or other GPS source) configured as GPS 1 as its primary data source.

If you have a GPS-250 puck as POS 2, then your system might be using it as the position source for the map and synthetic vision.

I find that the Dynon GPS is a lot more sensitive than say my Garmin 175 in my hanger, but do pull you aircraft outside and see if you get a position on POS 1.

The first thing I would check it if the GPS-2020 is up and running by going in to the setup menu, press and hold down buttons 7 and 8 at the same time until you are into the setup menu. Then go to System setup, then Serial Port setup, then serial port 5. Is the GPS-2020 detected and set as POS 1, and sending data out by the TX counter number going up? If it is, the press the back button, button 1, until you are in the main setup window. The go down to Local Display Setup, then GPS Fix Status. On the top right is will tell you what you are using for the present position source, the one giving you the map and synthetic vision position.

I don’t mean to ramble on, but these are things that should be checked out. The setup has things you can see that might help troubleshoot a problem, and sometimes it is just is setting that might just need to be changed.

If you want to do a little more troubleshooting, you can email me at [email protected] and I will do what I can to lead you down the right path.

Brian
 
Another possibility .... RF interference.

I have personally witnessed a bad portable puck GPS antenna (the inexpensive type) in a friend's airplane completely scramble GPS reception on every GPS device in the vicinity.

Not saying this is your issue, but want folks reading this thread to be cognizant that there is a very real possibility for a bad portable device in the cockpit to hose up the reception of permanently installed GPS antennas. Saw it with my own eyes.

I did lose GPS reception during one flight and if I remember correctly, I lost my flight path (track) and aircraft's position on the SkyView's map. I was about 10 or 15 miles away from my home base flying over a large steel plant at the time. Figured I would fly on for a couple of minutes before turning back towards home. After a few tense minutes all was good again. This only happened just that one time, so have chalked it up to some kind of interference along my flight path.
 
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I thought I would have some great information to share on what caused the outage but……..
I sprayed the connections on the back of the Dynon touch screen not an HDX model. Checked for security of the connectors and nothing seemed to correct the issue.

Came out to the plane a day or two later and everything works fine- no outage and it has been working since.????? My ADSB out is functioning!
 
Just had this happen to me...

Thought at first it might be GPS jamming....today after reseating and rejigging some wires seems to be better.....

Anyone have to replace their Dynon 2020 GPS Puck yet?
 
Thought at first it might be GPS jamming....today after reseating and rejigging some wires seems to be better.....

Anyone have to replace their Dynon 2020 GPS Puck yet?

A friend's RV-12 built by Synergy had Dynon GPS antenna wire cut through. Hole in mounting plate did not align with wires exiting bottom of amplified antenna...
 
I have been having the same problem as the OP for the past month. I have jiggled everything while watching the satellite screen, and at first I can create the signal loss but can't exactly locate the source. After fiddling with it at the antenna and in the radio bay for an hour or so it all starts acting normal. It will work in flight for another 10+ hours then act up again. This scenario has repeated 3 times now.

I will consider John-G's suggestion next time since it acts up. I have a Garmin antenna mounted next to the Dynon on the firewall tray. Although these 2 have played well for 1000 hours maybe the Garmin is actually the culprit.
 
I have been having the same problem as the OP for the past month. I have jiggled everything while watching the satellite screen, and at first I can create the signal loss but can't exactly locate the source. After fiddling with it at the antenna and in the radio bay for an hour or so it all starts acting normal. It will work in flight for another 10+ hours then act up again. This scenario has repeated 3 times now.

I will consider John-G's suggestion next time since it acts up. I have a Garmin antenna mounted next to the Dynon on the firewall tray. Although these 2 have played well for 1000 hours maybe the Garmin is actually the culprit.

I don't have any other GPS antenna mounted. Mine started within 7 hrs of updating to the latest Van's approved Dynon update on their downloads page. Dynon support seems to think it's wires. But I don't see any connection, pin or puck wire issues at all. Dynon says there are no slow or fast failure patterns they are seeing with the 2020 GPS puck.

It's definitely an intermittent issue which makes it all the more frustrating. And I'm guessing but I think it's a software problem but it's such an infrequent bug Dynon isn't catching it.

White Sands and military jamming practice doesn't help either. Gets you chasing your tail. Very annoying.
 
Hi Guys,

I've got this issue on a fresh 2020 install. Wiring is correct and has power/continuity. Setting are correct. This is really bugging me. I just want these issues gone so I can hit first flight.

Do you think the size of the mount hole could be the issue? Wires are in tack but maybe some interference? I'll widen and report back to note any change.

I doubt a brand new puck could be faulty, right....right?

Cheers,

Dan
 
A friend's RV-12 built by Synergy had Dynon GPS antenna wire cut through. Hole in mounting plate did not align with wires exiting bottom of amplified antenna...

Just so everyone is clear, the Dynon GPS (at least the SV-GPS-2020) looks like an antenna but is actually an antenna and GPS receiver all in one. It looks like a traditional GPS antenna but note there is no coax running to it, only wires. What comes out of it is NMEA serial data. It is a small nit but I find it helpful to have an accurate mental picture of the system configuration when considering failure modes. BTW, this and all the other comments are good ideas on troubleshooting.

Bob
 
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