I have a Series 5 with a 912ULS. I have had radio noise problems but recently have solved all but one. When transmitting the side tone is very noisey. I am told by unicoms and other planes in the pattern that my transmissions are loud and clear. I have an Icom A200 with a PS PM501 intercom. I use noise canceling headset and have added an Oregan Aero mic muff. This seems to help. I have gone thru all my grounding. I installed a Icom A210 in an RV-9A and it has internal menu to ajust sidetone, etc. ,but the A200 does not. Any ideas or suggestions appreciated.