Installed ground plane correct?

[n456ts]

Hello.
I'm looking for feedback on the transponder's antenna ground plane. I'm not a radio/ham guy, so I'm fairly ignorant here. In the past, I've only seen circular ground planes. Attached is a photo. X configuration made with foil tape on a composite airframe. Is this considered acceptable?

I'm looking into this because it would appear that the transponder is a bit weak. I've got a good size ADS-B receiver setup and despite times of good line of sight, the signal is lost or intermittent.

 

[preid]

a previous thread from Dynon on this-http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1328697560/5

 

[dynonsupport]

Please read our install manual which has specific instructions and requirements for a ground plane defined. It even tells you how to make your own.

 

[cessnadriver850]

being an old avionics guy and looking at your install. The aluminum tape I suppose has a sticky back. So when you cross over one piece the sticky back takes that piece out of the picture and you end up with only one side as an actual ground plane. go to the manual and make one as the book shows and see if that fixes your problem.

 

[dynonsupport]

Oh, and sorry, missed the photo before. An "X" ground plane is not acceptable. It needs to be solid out from the antenna by at least 120mm. An X will cause a very odd transmission pattern.

Also, as pointed out, you need a really solid electrical connection to the ground plane which tape may not give. We'd really recommend solid aluminum. Even aluminum foil from the kitchen will work fine!

 

[n456ts]

Thanks everyone. To be clear, this isn't my install. My aircraft was the first US built Allegro with all the Dynon goodies. As you can see, there were some learning curves. So, I'll be getting an LOA and correcting this. They also did the X foil tape with the radio and ELT antennas. They know me well, so it shouldn't be an issue getting the LOA.