Own Ship Called Out As Traffic...and..."No ADS-B-GPS Lost"

Dynon101

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I am still hearing the Dynon call out "TRAFFIC" and I look on the screen and I see a target at my exact place and altitude. It happens when I am in a turn and it is really annoying to the point of being dangerous because I am at the point where I am no longer feel the need to look...and that is NOT GOOD..

I have the SV-261 Transponder SN 04483 and the ADSB-472 PN 102985-000 SN 12806

The transponder and ADS-B antenna are mounted on the belly of the airplane pointed straight down 27 inches apart.

I know this has been an issue so I am hoping that there has been some kind of fix.

Also...the screen has a continuous "No ADS-B-GPS Lost" even though I see ADS-B traffic on the Dynon screen and my ForeFlight app (there is no other GPS receiver in the iPad nor is there a Stratus receiver in the airplane.

I know there is GPS reception because the Dynon knows where it is.

The airplane has both a Dynon GPS 250/A receiver and the Garmin GTN-650

THANKS for your help
 

andresmith76

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Have you gone into Setup > Traffic Setup Menu and set the Show Ghost Targets option to NO? (see attached)

Andre'
 

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KA4HRE

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I can't resist asking though I know I should... Why would you ever want the "Show Ghost Targets" to be "YES"?
 

Carl_Froehlich

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I suspect your ADS-b GPS position is coming from the GTN-650, not the SkyView 250 receiver (the 250 does not meet the ADS-b out criteria). As such your SkyView getting GPS signal does not mean the GTN-650 has a valid GPS postion.

Carl
 

Dynon101

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>I suspect your ADS-b GPS position is coming from the GTN-650, not the SkyView 250 receiver (the 250 does not meet the ADS-b out criteria).

Carl,

Thanks for your help.

Yes the configuration is such that the GPS input to my Dynon system is the GTN-650.


>As such your SkyView getting GPS signal does not mean the GTN-650 has a valid GPS position.

I am not clear on what this means however this is intriguing...

I am now wondering why the Dynon needs to have the GPS-250 connected at all if the GPS input is coming from the GTN? Is it true that the Dynon will not look for the GPS-250 until the other source of GPS position (GTN) is lost so the 250 is just a backup...or does the Dynon look at both the GTN and the 250 and this could be the problem?

THANKS AGAIN!!!
 

GKC Aviation

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May not be relative to your setup, but for the "No ADS-B-GPS Lost", go into your transponder setup and make sure the GPS source is correct for your installation. I forgot to do this recently on a new install, had the wrong GPS selected in the transponder setup.
 

Carl_Froehlich

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>I suspect your ADS-b GPS position is coming from the GTN-650, not the SkyView 250 receiver (the 250 does not meet the ADS-b out criteria).

Carl,

Thanks for your help.

Yes the configuration is such that the GPS input to my Dynon system is the GTN-650.


>As such your SkyView getting GPS signal does not mean the GTN-650 has a valid GPS position.

I am not clear on what this means however this is intriguing...

I am now wondering why the Dynon needs to have the GPS-250 connected at all if the GPS input is coming from the GTN? Is it true that the Dynon will not look for the GPS-250 until the other source of GPS position (GTN) is lost so the 250 is just a backup...or does the Dynon look at both the GTN and the 250 and this could be the problem?

THANKS AGAIN!!!
You want the SkyView GPS input to be the GPS-250, not the GTN-650. The GPS-250 provides the position information for your moving map, ADS-B in data, backup speed/altitude for the PFD display and such. The GTN-650 is your certified navigator for IFR - so it feeds the PFD (and autopilot) if you select the GTN-650 as your input. I always just have the GTN-650 feed the PFD so I don’t forget when flying IFR. This means all my flight plans are in the GTN-650, not the SkyView. This adds a step as the not so good folks at Garmin refuse to let ForeFlight transfer flight plans to the GTN-650 unless you cough up ~$2K for another Garmin add on that really costs less than $1.

When is Dynon coming out with its own IFR GPS Navigator??????

You could just have the GTN-650 feed the SkyView but I do not recommend that because:
- The GPS-250 will alway lock up postion faster than the GTN-650
- The two provide redundancy for IFR work

For VFR only you can just use the Dynon GPS-2020 receiver to meet ADS-B position requirements and not spring for the overpriced GTN-650. The GPS-250 does not have WAAS so it does not meet the ADS-B out rules.

Remember, for ADS-B out you have to configure to select the GTN-650, not the GPS-250.

Carl
 

Bill Putney

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The advantage of the Dynon GPS is that when the ships power dies completely, you’ll still know where you are and where you’re going for another 40 min or so because it’s powered by the SV battery. You could use the Garmin for a position source for the Dynon, but then you loose all your Nav (except what’s out the window and your whiskey compass) when the electrical system dies. If you happen to be flying at night or above a cloud layer, it’s nice to know where you are when you need to let down and look for a place to land.

I don’t imagine Dynon would have to do much, hardware-wise to make SkyView an IFR navigator. The new GPS is accurate enough and fast enough for ADS-B, so it should pass muster. But, it would have to be certified to meet the IFR navigator TSO spec. The EFIS would have to implement RAIM in software, but the hardware already has all the air data it needs for that. They might have to get the air data parts of the ADHRS certified IFR and they probably have to go through a more rigorous software certification than they did for the EFIS. It should certainly be an additional safety feature to have an IFR navigator with backup battery. I don’t know if any others.

But, that takes effort away from more certified autopilots and more new features for the base product. And it would take new thinking adjustment at the FAA. A lot of hurdles to jump. It’s not just Dynon not wanting to do it.
 

Dynon101

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Thanks Carl and Bill for the information. When I get to the airplane I will look to see what GPS is providing the system.

I do know that Dynon Tech Support had me setup the GTN as the GPS source for some reason and I think that it had to do with the ADS-B certification.
 

Rhino

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If you fly IFR, the reason they had you do that is because the Dynon GPS isn't legal for IFR. The GTN is.
 

Bill Putney

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I don’t think the older GPS will meet the refresh rate spec for the 2020 AFS-B mandate. The solution was to use an output from an IFR navigator. That saved some money over buying a new Dynon GPS.
 

Dynon

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I don’t think the older GPS will meet the refresh rate spec for the 2020 AFS-B mandate. The solution was to use an output from an IFR navigator. That saved some money over buying a new Dynon GPS.
It's not refresh rate as much as it is the nature of the integrity checking and verification that's inherent to the GPS design. The SV-GPS-250 actually has a slightly faster refresh rate than the SV-GPS-2020.
 
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