I have a Legacy 2010 RV12 with the Garmin SL-40 Radio...on the ground the reception is great, transmits great however in the air I'm getting static interference to the point where it's hard to make out what's being said. My transmissions are good in the air. This issue started a few weeks ago and seems to come and go, I've swapped out head sets, turned off strobes, nothing helps, after I land it's gone, reception is clear. I have ordered the blue capacitor that's mounted to the firewall, I've heard that it's needed when using Rotax engines to avert static interference. Maybe that's the problem but what confuses me is the on ground/inflight difference...anybody experience this?