Spent a couple of hours tracing an apparent earth problem. When the PTT button was activated, the trim indicators would go crazy. After finding no fault with my wiring, I looped the antenna cable through a ferrite core and the problem was solved to 99%. Rerouted the antenna wire along the side of the fuse, well away from any wires and now there is nill effect on any of the avionics.
Also installed the headset sockets and tied up the wires behind the seats
It's nice when things work out.
The green headset is a avcom and of coarse the other is a ZULU