On Saturday, August 18, 2018 at 2:18:16 PM UTC+2, Glidingstuff wrote:
Hi Chris and Dan

Yes the coax is connected to the aircraft ground. The aerials are correctly connected. Both aerial outlets are activated in the unit and are used. The Flarm transmit and receive aerial is on the top of the aircraft and the receive only aerial is underneath on the starboard side just behind the firewall.

Cheers

Paul

Then I would try disconnecting it at the antenna end.