First Flight with the Dynon HDX Dynon ADSB and Dynon Transponder

[LouRubin]

It was really exciting to see what these units
actually can do.Most everything worked fine
except the ADSB and Transponder. I have a feeling the antennas are too close together. There about 5 in apart and being a fiberglass aircraft not nearly enough ground plane.I’m also shooting thru the fiberglass.The controller said he was only getting a primary signal.I was able to receive traffic on the HDX so I’m confused why I’m getting a ADSB error . My local avionics shop won’t work on experimentals so I guess I’m on my own troubleshooting this issue.
Thoughts?

 

[airguy]

Reception of traffic coming in is from the ADSB-472 receiver unit. ATC seeing your aircraft (primary versus secondary) is in your transponder.

 

[-Bob]

5 inches apart?
That is MUCH too close. Each antenna should have ground plane around it, and the distance between them should be at least 2 feet. 3-4 feet is better. The transponder is a high-power pulsed transmitter. The ADSB-IN is a sensitive receiver. It is probably being completely overloaded by the powerful signal from the transponder.

 

[LouRubin]

That’s what I was thinking
I’m going to spread them apart and increase the ground plane size