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Mounting of GPS antenna for ADSB in.

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I'm preparing to install the Garmin GDL 82 ADSB in for my CTLS. the installer had some questions concerning where to mount the GPS antenna.  He also has some concerns whether a composite expert would be required to install the ground in the fuselage.  Any suggestions would be appreciated from anyone who has upgraded to ADSB.  Thanks..

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2 hours ago, FlyingMonkey said:

I'm planning to mount on the glareshield, if reception is poor I will mount it externally.

Same here.

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Any reason not to save $1000 and install the GDL-39? I have happily used for almost 2 years.

For installation advice Bill I recommend talking with PLANEMAKERS who installed my 39.

 

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14 minutes ago, NC Bill said:

Any reason not to save $1000 and install the GDL-39? I have happily used for almost 2 years.

For installation advice Bill I recommend talking with PLANEMAKERS who installed my 39.

 

The GDL39 is ADS-B IN only, you have to have both IN and OUT to be compliant with the 2020 mandate.  You also get a less complete traffic picture with IN only installed.

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Roger that.

I installed the DYNON gps-2020 (a drop in replacement for the gps 250) for ADS-B (out) for $590 + the GDL-39 ADS-B (in) for $849.

Just a thought.

 

 

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54 minutes ago, NC Bill said:

Any reason not to save $1000 and install the GDL-39? I have happily used for almost 2 years.

For installation advice Bill I recommend talking with PLANEMAKERS who installed my 39.

 

Thanks, Bill.

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2 hours ago, NC Bill said:

Roger that.

I installed the DYNON gps-2020 (a drop in replacement for the gps 250) for ADS-B (out) for $590 + the GDL-39 ADS-B (in) for $849.

Just a thought.

 

 

Ah, that makes sense.  I don’t have Skyview, so the Garmin GDL82 or uAvionix EchoUAT are my best bets.  I will probably do the latter and use the price difference to upgrade my 496 to an iFly 740b.

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I installed my ADS-B, including the "in" and "out" antennas.  it is really easy to make a ground plane for the antenna.  Just take some heavy duty aluminum foil and glue this onto the fuselage where the antenna will be located.  I did not install the Garmin ADS-B and this requires a licensed Garmin shop to do this.  I imagine a Garmin shop might use a thin aluminum sheet for the ground plane but this performs the same as the foil.  The size needed for the ground plane isn't that large.  if space allows, a 10" by 10" square piece of aluminum is adequate.  The GPS antenna would be mounted on the roof of the aircraft and this can be just about anywhere that is convenient.  The GPS antenna for my ADS-B didn't require a ground plane and, although I might be wrong, I don't think that the Garmin GPS antenna requires a ground plane either.

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10 hours ago, Runtoeat said:

I installed my ADS-B, including the "in" and "out" antennas.  it is really easy to make a ground plane for the antenna.  Just take some heavy duty aluminum foil and glue this onto the fuselage where the antenna will be located.  I did not install the Garmin ADS-B and this requires a licensed Garmin shop to do this.  I imagine a Garmin shop might use a thin aluminum sheet for the ground plane but this performs the same as the foil.  The size needed for the ground plane isn't that large.  if space allows, a 10" by 10" square piece of aluminum is adequate.  The GPS antenna would be mounted on the roof of the aircraft and this can be just about anywhere that is convenient.  The GPS antenna for my ADS-B didn't require a ground plane and, although I might be wrong, I don't think that the Garmin GPS antenna requires a ground plane either.

Dick, thanks for the info.  uAvionix specifically says the heavy foil solution is good to go, so it should be good.  10" seems pretty big, uAvionix recoomends a minimum of 120mm (4.7").  Where did you mount your antenna that you could find 10"?  I want to mount mine just ahead of the ELT in the tunnel under the access panel in the baggage bay, but it will be tight on space for the ground plane.

Does anybody know if it's acceptable to wrap the ground plane up on the sides of the tunnel to gain more size, or does it need to be flat and perpendicular to the antenna?   

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3 hours ago, FlyingMonkey said:

Dick, thanks for the info.  uAvionix specifically says the heavy foil solution is good to go, so it should be good.  10" seems pretty big, uAvionix recoomends a minimum of 120mm (4.7").  Where did you mount your antenna that you could find 10"?  I want to mount mine just ahead of the ELT in the tunnel under the access panel in the baggage bay, but it will be tight on space for the ground plane.

Does anybody know if it's acceptable to wrap the ground plane up on the sides of the tunnel to gain more size, or does it need to be flat and perpendicular to the antenna?   

I put my GPS  on the glare shield and it works just great.  Almost anywhere in the A/C would work fine,  Composit is

transparent for GPS (and most else)

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21 minutes ago, Mick said:

I put my GPS  on the glare shield and it works just great.  Almost anywhere in the A/C would work fine,  Composit is

transparent for GPS (and most else)

We  mounted 2 external gps antenna 12 years ago.  Lately I notice any device I bring into the cockpit acquires better / faster just being in the cockpit.

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27 minutes ago, Mick said:

I put my GPS  on the glare shield and it works just great.  Almost anywhere in the A/C would work fine,  Composit is

transparent for GPS (and most else)

The GPS antenna is not a problem, I was asking about the ADS-B 978/1090 antenna(s), which transmit and thus require a ground plane on composite airplanes.

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Has FD issued a fleet wide authorization for the GDL 82 in our planes?  Did you each have to request an MRA or are you all experimental?

Danny

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Hi Andy.  Yes, less than 10" works. I was just being generous by suggesting 10" if space permits.  This could be on the ceiling or the floor back behind our cargo bay.  I have mounted Delta Pop antennas on the belly of my CTSW in the tunnel area, forward of the bulkhead as you are planning on doing.    I used a piece of heavy duty aluminum foil which was about 6" but will take a look or see if I have some pictures of this.  I used contact adhesive and it was a little tricky getting the foil down flat to the floor past all of the cables and wires.in the tunnel. The SkyGuard requires separate antennas for the UAT "in and out" so there are two Delta Pops for this.  My Garmin 327 xponder has it's own Delta Pop antenna.  3 Delta Pops on the belly.  The SkyGuard has a small rubber ducky antenna mounted on it which receives 1090 "in".  The SkyGuard GPS antenna is powered (one small coax for signal/power) and I installed this inside my cabin, at the ceiling behind my head so it looks out the skylight.  I get great signal incoming and outgoing for ADS-B and GPS with no RFI problems with surrounding equipment.  It all sound "busy" describing it here but it was easy to install and because it's wireless to my iFly GPS and for the squawk and PA from the xponder, it is a neat installation with the only wire showing being the small short run of coax up the bulkhead to the small ceiling GPS antenna.

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The GPS of course would not need a ground plane, just the UAT transmit. Maybe they are sharing with GPS?  Wait, the GDL 82 uses the existing transponder antenna for transponder and UAT in/out I think. The GPS is on its own, so no need for ground plane, since it doesn't transmit. Anywho, I asked about using the GDL 82 and was told it would not work with my mode S transponder, only mode C's. So I guess its back to uAvionix.

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Tom, my friend installed Garmin ADS-B in his CTLS.  Pretty sure he has the Garmin GTX330 mode S xponder and he installed the Garmin GDL84 ADS-B "in/out".  He also installed the Garmin "Flight Stream" to wirelessly receive xponder data and to send ADS-B data to iPad for viewing.  Maybe the GDL84 would work for you situation with mode S?

https://buy.garmin.com/en-US/US/p/511180

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Thanks for the info. Its an intriguing box, but I think the uAvionix system is similar, with a wifi output to several EFB's including my current favorite Avare and at about the $1500 zone. A further issue for many is communicating TIS and FIS data to their panel GPS such as the 396, 496 and my 696. Currently the only product available is the GDL 39 at the $600 price point, which it  looks like I will be using. Its either that or toss out the 696 and mount a 795 to get Bluetooth data from a Garmin product, like the GTX 345 ($5000).  Sigh ... there's just too much to think about.

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On 2/28/2018 at 12:49 PM, FlyingMonkey said:

The GDL39 is ADS-B IN only, you have to have both IN and OUT to be compliant with the 2020 mandate.  You also get a less complete traffic picture with IN only installed.

Andy - I thought the FAA only required "OUT" or did I miss something?

But, without "IN", you don't get traffic or weather as I understand it. To me that's the best part.

The shop installed the GPS antenna for my Garmin 345 transponder on top immediately adjacent to the left flap. Works great.

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On 3/11/2018 at 1:41 PM, sandpiper said:

Andy - I thought the FAA only required "OUT" or did I miss something?

But, without "IN", you don't get traffic or weather as I understand it. To me that's the best part.

The shop installed the GPS antenna for my Garmin 345 transponder on top immediately adjacent to the left flap. Works great.

You are right, brain fart.  OUT only is required.  I just always wonder to myself why anybody would install just OUT and not take advantage of IN data.  Maybe if you have a jet with TCAS and radar...  :)

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On 3/11/2018 at 7:16 PM, John Vance said:

Arian at FD provided the attached drawing for the GPS antenna installation free of charge when I was installing my system.   My avionics guy installed the antenna per the drawing, with a slight modification - he used an aluminum plate on the cabin ceiling to prevent compression of the foam core rather than the bushings that are shown.  I went with the Garmin 345, and got the FAA rebate, which requires a short in-flight test to prove that the system works, so I can vouch for the location specified by FD.

 

GPS antenna installation1.pdf

I can't see the document at that link, John.

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