I have a RFI problem. I operate hf mobile. I use a kenwood ts 440s and a tarheel antenna. When I'm on 75 and 20 meter phone and when I increase the power ( mic gain ) everyone reports to me that I have RFI on my signal.I have tried low pass filters, torrides,line isolators,ground wires, differant coxa's, and everything I have tried, nothing works. HELP!!!