Andy thnks again for your interest and comprehensive reply. Will pass on your comments to the shop where i am getting Radio tested again.
No change in Headset. Am using David Clark ProX and tested other Headsets in both sides with no difference.
The problem is big distortion on transmit with engine both running and stopped. The problem arose a week ago when taxiing at Bankstown without any warning.
Today the first Radio shop i tried said that it worked fine on the Bench so it MUST be the Antenna, and because they couldnt get to it, i was told, sorry mate, cant help you.
Andy, have you heard of any instances where Jab antennas have been replaced?
Anyway, lets see what happens on the second opinion scenario. Will keep you all posted
Cheers Roscoe