I'm at wits end. I installed a ICOM ICA210 radio in my EAB RV -12. When I have the intercom on I get a lot of engine noise above 3000 rpm. And it gets worse the higher I go. With the intercom off I don't get the noise and can hear the tower or other planes just fine. I'm using the same jacks, headset, and I assume audio ouput on the radio. Should I have a choke installed on the power side, and if so what size and how does it get wired? I hope someone out there can help. I have all the grounds at one place so I don't think I have a ground loop.