Planning HDX1100's and Avidyne GPS/NAV/COM - how many GPS antenna and where?

[wswimpso1]

The title pretty well sums it up. Building a fiberglass airplane, lots of buried and/or internal antenna.

I know I need a GPS 2020 antenna/receiver to provide GPS signal to my Dynon array, and plan to put it under the turtledeck, which is high and a long ways from other metal items. I like that. But with the bird being IFR and having an Avidyne IFD440 in the panel, it too needs a GPS position source.

Does it work OK to port GPS position data from Dynon to Avidyne?

Is it smart to run only one GPS position source given the IFR mission? Does anyone else run a second antenna for the Avidyne?

Last, can we connect the GPS position data between the Dynon and Avidyne even when they both have their own antenna?

Thanks,

Billski

 

[John Lucas]

You will have to install a separate antenna for the Avidyne 440. The Dynon panel will allow you to select what your nav data source is inflight. I almost always use the 440 since it is IFR certified and I load my flight plan through that, either directly or using the iPad IFD100 app.

 

[Carl_Froehlich]

I suggest two GPS antennas.

The Avidyne 440 requires its TSO antenna to be legal for IFR work. The Dynon antenna feeds the SkyView moving map and such.

What you could do is get the non-WAAS Dynon GPS 250 as option to the GPS 2020. Use a serial output from the Avidyne to feed the SkyView XPDR for ADS-b out. The 250 sells for $250. The 2020 sells for $890.

The 2020 option is perfect for those non-IFR birds to be ADS-B out compliant. The 250 is as good as the 2020 for everything else.

Carl

 

[CanardMulti]

As said above, the Avidyne and Skyview each need their own antenna.

Keep in mind that the Dynon unit is both an antenna AND a GPS receiver. The wiring for the Dynon units is only for power, ground, and data. There is no antenna cable for the Dynon GPS-2020 or GPS250. Skyview uses position for a lot more than its VFR navigation capabilities. Provided you're using the Dynon transponder, to make the system ADSB-out legal it needs position from either a GPS-2020 or from an IFR legal WAAS GPS navigator.

Each position source you choose to make available to Skyview uses up one of your 5 serial data ports. In setup you designate which it goes to first and where to go next if your #1 choice fails. My system originally had 2 GPS250s with the primary outside on the aft turtle deck and the secondary under the composite avionics bay cover. When I upgraded to the GPS-2020 to be ADSB-out compliant, I replaced the -250 on the turtle deck. When I installed my Avidyne IFD540, I put its GPS antenna on a small composite shelf in the avionics bay that mirrors the GPS-250s location with a desire to keep the antenna cable run short. So far both have been rock sold, despite their proximity to a very electronically busy location. Knock wood. I had already used all 5 of my serial ports or I would have added it as #2 in the position fail down line up.

Ken