I used a francis antenna with a connex and had a lot less modulation than with my old stainless whip, so I went back. I know most of the time when a radio interferes with computers and electrical parts it's because of stray RF. Ground that radio, and everything else real good and try it again. If that doesn't work try some snap on ferrite cores from radio shack. they go round the power wires for devices that receive interference from radios. rerouting your coax may also do the trick. Just remember that 4600 has a built in kicker. It's gonna do some odd things to your electrical if it's not installed right..